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Gentoo's Bugzilla – Attachment 280899 Details for
Bug 376325
sys-kernel/gentoo-sources-3.0 please add patch for zcache
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[patch]
fix zcache build
zc.patch (text/plain), 92.50 KB, created by
Marcin Mirosław
on 2011-07-25 10:17:49 UTC
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Description:
fix zcache build
Filename:
MIME Type:
Creator:
Marcin Mirosław
Created:
2011-07-25 10:17:49 UTC
Size:
92.50 KB
patch
obsolete
>diff -urN drivers.old//staging/zcache/Makefile drivers//staging/zcache/Makefile >--- drivers.old//staging/zcache/Makefile 2011-07-22 04:17:23.000000000 +0200 >+++ drivers//staging/zcache/Makefile 2011-07-25 12:02:14.028241844 +0200 >@@ -1,3 +1,3 @@ >-zcache-y := tmem.o >+zcache-y := zcache_drv.o tmem.o > > obj-$(CONFIG_ZCACHE) += zcache.o >diff -urN drivers.old//staging/zcache/zcache.c drivers//staging/zcache/zcache.c >--- drivers.old//staging/zcache/zcache.c 2011-07-22 04:17:23.000000000 +0200 >+++ drivers//staging/zcache/zcache.c 1970-01-01 01:00:00.000000000 +0100 >@@ -1,1661 +0,0 @@ >-/* >- * zcache.c >- * >- * Copyright (c) 2010,2011, Dan Magenheimer, Oracle Corp. >- * Copyright (c) 2010,2011, Nitin Gupta >- * >- * Zcache provides an in-kernel "host implementation" for transcendent memory >- * and, thus indirectly, for cleancache and frontswap. Zcache includes two >- * page-accessible memory [1] interfaces, both utilizing lzo1x compression: >- * 1) "compression buddies" ("zbud") is used for ephemeral pages >- * 2) xvmalloc is used for persistent pages. >- * Xvmalloc (based on the TLSF allocator) has very low fragmentation >- * so maximizes space efficiency, while zbud allows pairs (and potentially, >- * in the future, more than a pair of) compressed pages to be closely linked >- * so that reclaiming can be done via the kernel's physical-page-oriented >- * "shrinker" interface. >- * >- * [1] For a definition of page-accessible memory (aka PAM), see: >- * http://marc.info/?l=linux-mm&m=127811271605009 >- */ >- >-#include <linux/cpu.h> >-#include <linux/highmem.h> >-#include <linux/list.h> >-#include <linux/lzo.h> >-#include <linux/slab.h> >-#include <linux/spinlock.h> >-#include <linux/types.h> >-#include <linux/atomic.h> >-#include "tmem.h" >- >-#include "../zram/xvmalloc.h" /* if built in drivers/staging */ >- >-#if (!defined(CONFIG_CLEANCACHE) && !defined(CONFIG_FRONTSWAP)) >-#error "zcache is useless without CONFIG_CLEANCACHE or CONFIG_FRONTSWAP" >-#endif >-#ifdef CONFIG_CLEANCACHE >-#include <linux/cleancache.h> >-#endif >-#ifdef CONFIG_FRONTSWAP >-#include <linux/frontswap.h> >-#endif >- >-#if 0 >-/* this is more aggressive but may cause other problems? */ >-#define ZCACHE_GFP_MASK (GFP_ATOMIC | __GFP_NORETRY | __GFP_NOWARN) >-#else >-#define ZCACHE_GFP_MASK \ >- (__GFP_FS | __GFP_NORETRY | __GFP_NOWARN | __GFP_NOMEMALLOC) >-#endif >- >-/********** >- * Compression buddies ("zbud") provides for packing two (or, possibly >- * in the future, more) compressed ephemeral pages into a single "raw" >- * (physical) page and tracking them with data structures so that >- * the raw pages can be easily reclaimed. >- * >- * A zbud page ("zbpg") is an aligned page containing a list_head, >- * a lock, and two "zbud headers". The remainder of the physical >- * page is divided up into aligned 64-byte "chunks" which contain >- * the compressed data for zero, one, or two zbuds. Each zbpg >- * resides on: (1) an "unused list" if it has no zbuds; (2) a >- * "buddied" list if it is fully populated with two zbuds; or >- * (3) one of PAGE_SIZE/64 "unbuddied" lists indexed by how many chunks >- * the one unbuddied zbud uses. The data inside a zbpg cannot be >- * read or written unless the zbpg's lock is held. >- */ >- >-#define ZBH_SENTINEL 0x43214321 >-#define ZBPG_SENTINEL 0xdeadbeef >- >-#define ZBUD_MAX_BUDS 2 >- >-struct zbud_hdr { >- uint32_t pool_id; >- struct tmem_oid oid; >- uint32_t index; >- uint16_t size; /* compressed size in bytes, zero means unused */ >- DECL_SENTINEL >-}; >- >-struct zbud_page { >- struct list_head bud_list; >- spinlock_t lock; >- struct zbud_hdr buddy[ZBUD_MAX_BUDS]; >- DECL_SENTINEL >- /* followed by NUM_CHUNK aligned CHUNK_SIZE-byte chunks */ >-}; >- >-#define CHUNK_SHIFT 6 >-#define CHUNK_SIZE (1 << CHUNK_SHIFT) >-#define CHUNK_MASK (~(CHUNK_SIZE-1)) >-#define NCHUNKS (((PAGE_SIZE - sizeof(struct zbud_page)) & \ >- CHUNK_MASK) >> CHUNK_SHIFT) >-#define MAX_CHUNK (NCHUNKS-1) >- >-static struct { >- struct list_head list; >- unsigned count; >-} zbud_unbuddied[NCHUNKS]; >-/* list N contains pages with N chunks USED and NCHUNKS-N unused */ >-/* element 0 is never used but optimizing that isn't worth it */ >-static unsigned long zbud_cumul_chunk_counts[NCHUNKS]; >- >-struct list_head zbud_buddied_list; >-static unsigned long zcache_zbud_buddied_count; >- >-/* protects the buddied list and all unbuddied lists */ >-static DEFINE_SPINLOCK(zbud_budlists_spinlock); >- >-static LIST_HEAD(zbpg_unused_list); >-static unsigned long zcache_zbpg_unused_list_count; >- >-/* protects the unused page list */ >-static DEFINE_SPINLOCK(zbpg_unused_list_spinlock); >- >-static atomic_t zcache_zbud_curr_raw_pages; >-static atomic_t zcache_zbud_curr_zpages; >-static unsigned long zcache_zbud_curr_zbytes; >-static unsigned long zcache_zbud_cumul_zpages; >-static unsigned long zcache_zbud_cumul_zbytes; >-static unsigned long zcache_compress_poor; >- >-/* forward references */ >-static void *zcache_get_free_page(void); >-static void zcache_free_page(void *p); >- >-/* >- * zbud helper functions >- */ >- >-static inline unsigned zbud_max_buddy_size(void) >-{ >- return MAX_CHUNK << CHUNK_SHIFT; >-} >- >-static inline unsigned zbud_size_to_chunks(unsigned size) >-{ >- BUG_ON(size == 0 || size > zbud_max_buddy_size()); >- return (size + CHUNK_SIZE - 1) >> CHUNK_SHIFT; >-} >- >-static inline int zbud_budnum(struct zbud_hdr *zh) >-{ >- unsigned offset = (unsigned long)zh & (PAGE_SIZE - 1); >- struct zbud_page *zbpg = NULL; >- unsigned budnum = -1U; >- int i; >- >- for (i = 0; i < ZBUD_MAX_BUDS; i++) >- if (offset == offsetof(typeof(*zbpg), buddy[i])) { >- budnum = i; >- break; >- } >- BUG_ON(budnum == -1U); >- return budnum; >-} >- >-static char *zbud_data(struct zbud_hdr *zh, unsigned size) >-{ >- struct zbud_page *zbpg; >- char *p; >- unsigned budnum; >- >- ASSERT_SENTINEL(zh, ZBH); >- budnum = zbud_budnum(zh); >- BUG_ON(size == 0 || size > zbud_max_buddy_size()); >- zbpg = container_of(zh, struct zbud_page, buddy[budnum]); >- ASSERT_SPINLOCK(&zbpg->lock); >- p = (char *)zbpg; >- if (budnum == 0) >- p += ((sizeof(struct zbud_page) + CHUNK_SIZE - 1) & >- CHUNK_MASK); >- else if (budnum == 1) >- p += PAGE_SIZE - ((size + CHUNK_SIZE - 1) & CHUNK_MASK); >- return p; >-} >- >-/* >- * zbud raw page management >- */ >- >-static struct zbud_page *zbud_alloc_raw_page(void) >-{ >- struct zbud_page *zbpg = NULL; >- struct zbud_hdr *zh0, *zh1; >- bool recycled = 0; >- >- /* if any pages on the zbpg list, use one */ >- spin_lock(&zbpg_unused_list_spinlock); >- if (!list_empty(&zbpg_unused_list)) { >- zbpg = list_first_entry(&zbpg_unused_list, >- struct zbud_page, bud_list); >- list_del_init(&zbpg->bud_list); >- zcache_zbpg_unused_list_count--; >- recycled = 1; >- } >- spin_unlock(&zbpg_unused_list_spinlock); >- if (zbpg == NULL) >- /* none on zbpg list, try to get a kernel page */ >- zbpg = zcache_get_free_page(); >- if (likely(zbpg != NULL)) { >- INIT_LIST_HEAD(&zbpg->bud_list); >- zh0 = &zbpg->buddy[0]; zh1 = &zbpg->buddy[1]; >- spin_lock_init(&zbpg->lock); >- if (recycled) { >- ASSERT_INVERTED_SENTINEL(zbpg, ZBPG); >- SET_SENTINEL(zbpg, ZBPG); >- BUG_ON(zh0->size != 0 || tmem_oid_valid(&zh0->oid)); >- BUG_ON(zh1->size != 0 || tmem_oid_valid(&zh1->oid)); >- } else { >- atomic_inc(&zcache_zbud_curr_raw_pages); >- INIT_LIST_HEAD(&zbpg->bud_list); >- SET_SENTINEL(zbpg, ZBPG); >- zh0->size = 0; zh1->size = 0; >- tmem_oid_set_invalid(&zh0->oid); >- tmem_oid_set_invalid(&zh1->oid); >- } >- } >- return zbpg; >-} >- >-static void zbud_free_raw_page(struct zbud_page *zbpg) >-{ >- struct zbud_hdr *zh0 = &zbpg->buddy[0], *zh1 = &zbpg->buddy[1]; >- >- ASSERT_SENTINEL(zbpg, ZBPG); >- BUG_ON(!list_empty(&zbpg->bud_list)); >- ASSERT_SPINLOCK(&zbpg->lock); >- BUG_ON(zh0->size != 0 || tmem_oid_valid(&zh0->oid)); >- BUG_ON(zh1->size != 0 || tmem_oid_valid(&zh1->oid)); >- INVERT_SENTINEL(zbpg, ZBPG); >- spin_unlock(&zbpg->lock); >- spin_lock(&zbpg_unused_list_spinlock); >- list_add(&zbpg->bud_list, &zbpg_unused_list); >- zcache_zbpg_unused_list_count++; >- spin_unlock(&zbpg_unused_list_spinlock); >-} >- >-/* >- * core zbud handling routines >- */ >- >-static unsigned zbud_free(struct zbud_hdr *zh) >-{ >- unsigned size; >- >- ASSERT_SENTINEL(zh, ZBH); >- BUG_ON(!tmem_oid_valid(&zh->oid)); >- size = zh->size; >- BUG_ON(zh->size == 0 || zh->size > zbud_max_buddy_size()); >- zh->size = 0; >- tmem_oid_set_invalid(&zh->oid); >- INVERT_SENTINEL(zh, ZBH); >- zcache_zbud_curr_zbytes -= size; >- atomic_dec(&zcache_zbud_curr_zpages); >- return size; >-} >- >-static void zbud_free_and_delist(struct zbud_hdr *zh) >-{ >- unsigned chunks; >- struct zbud_hdr *zh_other; >- unsigned budnum = zbud_budnum(zh), size; >- struct zbud_page *zbpg = >- container_of(zh, struct zbud_page, buddy[budnum]); >- >- spin_lock(&zbpg->lock); >- if (list_empty(&zbpg->bud_list)) { >- /* ignore zombie page... see zbud_evict_pages() */ >- spin_unlock(&zbpg->lock); >- return; >- } >- size = zbud_free(zh); >- ASSERT_SPINLOCK(&zbpg->lock); >- zh_other = &zbpg->buddy[(budnum == 0) ? 1 : 0]; >- if (zh_other->size == 0) { /* was unbuddied: unlist and free */ >- chunks = zbud_size_to_chunks(size) ; >- spin_lock(&zbud_budlists_spinlock); >- BUG_ON(list_empty(&zbud_unbuddied[chunks].list)); >- list_del_init(&zbpg->bud_list); >- zbud_unbuddied[chunks].count--; >- spin_unlock(&zbud_budlists_spinlock); >- zbud_free_raw_page(zbpg); >- } else { /* was buddied: move remaining buddy to unbuddied list */ >- chunks = zbud_size_to_chunks(zh_other->size) ; >- spin_lock(&zbud_budlists_spinlock); >- list_del_init(&zbpg->bud_list); >- zcache_zbud_buddied_count--; >- list_add_tail(&zbpg->bud_list, &zbud_unbuddied[chunks].list); >- zbud_unbuddied[chunks].count++; >- spin_unlock(&zbud_budlists_spinlock); >- spin_unlock(&zbpg->lock); >- } >-} >- >-static struct zbud_hdr *zbud_create(uint32_t pool_id, struct tmem_oid *oid, >- uint32_t index, struct page *page, >- void *cdata, unsigned size) >-{ >- struct zbud_hdr *zh0, *zh1, *zh = NULL; >- struct zbud_page *zbpg = NULL, *ztmp; >- unsigned nchunks; >- char *to; >- int i, found_good_buddy = 0; >- >- nchunks = zbud_size_to_chunks(size) ; >- for (i = MAX_CHUNK - nchunks + 1; i > 0; i--) { >- spin_lock(&zbud_budlists_spinlock); >- if (!list_empty(&zbud_unbuddied[i].list)) { >- list_for_each_entry_safe(zbpg, ztmp, >- &zbud_unbuddied[i].list, bud_list) { >- if (spin_trylock(&zbpg->lock)) { >- found_good_buddy = i; >- goto found_unbuddied; >- } >- } >- } >- spin_unlock(&zbud_budlists_spinlock); >- } >- /* didn't find a good buddy, try allocating a new page */ >- zbpg = zbud_alloc_raw_page(); >- if (unlikely(zbpg == NULL)) >- goto out; >- /* ok, have a page, now compress the data before taking locks */ >- spin_lock(&zbpg->lock); >- spin_lock(&zbud_budlists_spinlock); >- list_add_tail(&zbpg->bud_list, &zbud_unbuddied[nchunks].list); >- zbud_unbuddied[nchunks].count++; >- zh = &zbpg->buddy[0]; >- goto init_zh; >- >-found_unbuddied: >- ASSERT_SPINLOCK(&zbpg->lock); >- zh0 = &zbpg->buddy[0]; zh1 = &zbpg->buddy[1]; >- BUG_ON(!((zh0->size == 0) ^ (zh1->size == 0))); >- if (zh0->size != 0) { /* buddy0 in use, buddy1 is vacant */ >- ASSERT_SENTINEL(zh0, ZBH); >- zh = zh1; >- } else if (zh1->size != 0) { /* buddy1 in use, buddy0 is vacant */ >- ASSERT_SENTINEL(zh1, ZBH); >- zh = zh0; >- } else >- BUG(); >- list_del_init(&zbpg->bud_list); >- zbud_unbuddied[found_good_buddy].count--; >- list_add_tail(&zbpg->bud_list, &zbud_buddied_list); >- zcache_zbud_buddied_count++; >- >-init_zh: >- SET_SENTINEL(zh, ZBH); >- zh->size = size; >- zh->index = index; >- zh->oid = *oid; >- zh->pool_id = pool_id; >- /* can wait to copy the data until the list locks are dropped */ >- spin_unlock(&zbud_budlists_spinlock); >- >- to = zbud_data(zh, size); >- memcpy(to, cdata, size); >- spin_unlock(&zbpg->lock); >- zbud_cumul_chunk_counts[nchunks]++; >- atomic_inc(&zcache_zbud_curr_zpages); >- zcache_zbud_cumul_zpages++; >- zcache_zbud_curr_zbytes += size; >- zcache_zbud_cumul_zbytes += size; >-out: >- return zh; >-} >- >-static int zbud_decompress(struct page *page, struct zbud_hdr *zh) >-{ >- struct zbud_page *zbpg; >- unsigned budnum = zbud_budnum(zh); >- size_t out_len = PAGE_SIZE; >- char *to_va, *from_va; >- unsigned size; >- int ret = 0; >- >- zbpg = container_of(zh, struct zbud_page, buddy[budnum]); >- spin_lock(&zbpg->lock); >- if (list_empty(&zbpg->bud_list)) { >- /* ignore zombie page... see zbud_evict_pages() */ >- ret = -EINVAL; >- goto out; >- } >- ASSERT_SENTINEL(zh, ZBH); >- BUG_ON(zh->size == 0 || zh->size > zbud_max_buddy_size()); >- to_va = kmap_atomic(page, KM_USER0); >- size = zh->size; >- from_va = zbud_data(zh, size); >- ret = lzo1x_decompress_safe(from_va, size, to_va, &out_len); >- BUG_ON(ret != LZO_E_OK); >- BUG_ON(out_len != PAGE_SIZE); >- kunmap_atomic(to_va, KM_USER0); >-out: >- spin_unlock(&zbpg->lock); >- return ret; >-} >- >-/* >- * The following routines handle shrinking of ephemeral pages by evicting >- * pages "least valuable" first. >- */ >- >-static unsigned long zcache_evicted_raw_pages; >-static unsigned long zcache_evicted_buddied_pages; >-static unsigned long zcache_evicted_unbuddied_pages; >- >-static struct tmem_pool *zcache_get_pool_by_id(uint32_t poolid); >-static void zcache_put_pool(struct tmem_pool *pool); >- >-/* >- * Flush and free all zbuds in a zbpg, then free the pageframe >- */ >-static void zbud_evict_zbpg(struct zbud_page *zbpg) >-{ >- struct zbud_hdr *zh; >- int i, j; >- uint32_t pool_id[ZBUD_MAX_BUDS], index[ZBUD_MAX_BUDS]; >- struct tmem_oid oid[ZBUD_MAX_BUDS]; >- struct tmem_pool *pool; >- >- ASSERT_SPINLOCK(&zbpg->lock); >- BUG_ON(!list_empty(&zbpg->bud_list)); >- for (i = 0, j = 0; i < ZBUD_MAX_BUDS; i++) { >- zh = &zbpg->buddy[i]; >- if (zh->size) { >- pool_id[j] = zh->pool_id; >- oid[j] = zh->oid; >- index[j] = zh->index; >- j++; >- zbud_free(zh); >- } >- } >- spin_unlock(&zbpg->lock); >- for (i = 0; i < j; i++) { >- pool = zcache_get_pool_by_id(pool_id[i]); >- if (pool != NULL) { >- tmem_flush_page(pool, &oid[i], index[i]); >- zcache_put_pool(pool); >- } >- } >- ASSERT_SENTINEL(zbpg, ZBPG); >- spin_lock(&zbpg->lock); >- zbud_free_raw_page(zbpg); >-} >- >-/* >- * Free nr pages. This code is funky because we want to hold the locks >- * protecting various lists for as short a time as possible, and in some >- * circumstances the list may change asynchronously when the list lock is >- * not held. In some cases we also trylock not only to avoid waiting on a >- * page in use by another cpu, but also to avoid potential deadlock due to >- * lock inversion. >- */ >-static void zbud_evict_pages(int nr) >-{ >- struct zbud_page *zbpg; >- int i; >- >- /* first try freeing any pages on unused list */ >-retry_unused_list: >- spin_lock_bh(&zbpg_unused_list_spinlock); >- if (!list_empty(&zbpg_unused_list)) { >- /* can't walk list here, since it may change when unlocked */ >- zbpg = list_first_entry(&zbpg_unused_list, >- struct zbud_page, bud_list); >- list_del_init(&zbpg->bud_list); >- zcache_zbpg_unused_list_count--; >- atomic_dec(&zcache_zbud_curr_raw_pages); >- spin_unlock_bh(&zbpg_unused_list_spinlock); >- zcache_free_page(zbpg); >- zcache_evicted_raw_pages++; >- if (--nr <= 0) >- goto out; >- goto retry_unused_list; >- } >- spin_unlock_bh(&zbpg_unused_list_spinlock); >- >- /* now try freeing unbuddied pages, starting with least space avail */ >- for (i = 0; i < MAX_CHUNK; i++) { >-retry_unbud_list_i: >- spin_lock_bh(&zbud_budlists_spinlock); >- if (list_empty(&zbud_unbuddied[i].list)) { >- spin_unlock_bh(&zbud_budlists_spinlock); >- continue; >- } >- list_for_each_entry(zbpg, &zbud_unbuddied[i].list, bud_list) { >- if (unlikely(!spin_trylock(&zbpg->lock))) >- continue; >- list_del_init(&zbpg->bud_list); >- zbud_unbuddied[i].count--; >- spin_unlock(&zbud_budlists_spinlock); >- zcache_evicted_unbuddied_pages++; >- /* want budlists unlocked when doing zbpg eviction */ >- zbud_evict_zbpg(zbpg); >- local_bh_enable(); >- if (--nr <= 0) >- goto out; >- goto retry_unbud_list_i; >- } >- spin_unlock_bh(&zbud_budlists_spinlock); >- } >- >- /* as a last resort, free buddied pages */ >-retry_bud_list: >- spin_lock_bh(&zbud_budlists_spinlock); >- if (list_empty(&zbud_buddied_list)) { >- spin_unlock_bh(&zbud_budlists_spinlock); >- goto out; >- } >- list_for_each_entry(zbpg, &zbud_buddied_list, bud_list) { >- if (unlikely(!spin_trylock(&zbpg->lock))) >- continue; >- list_del_init(&zbpg->bud_list); >- zcache_zbud_buddied_count--; >- spin_unlock(&zbud_budlists_spinlock); >- zcache_evicted_buddied_pages++; >- /* want budlists unlocked when doing zbpg eviction */ >- zbud_evict_zbpg(zbpg); >- local_bh_enable(); >- if (--nr <= 0) >- goto out; >- goto retry_bud_list; >- } >- spin_unlock_bh(&zbud_budlists_spinlock); >-out: >- return; >-} >- >-static void zbud_init(void) >-{ >- int i; >- >- INIT_LIST_HEAD(&zbud_buddied_list); >- zcache_zbud_buddied_count = 0; >- for (i = 0; i < NCHUNKS; i++) { >- INIT_LIST_HEAD(&zbud_unbuddied[i].list); >- zbud_unbuddied[i].count = 0; >- } >-} >- >-#ifdef CONFIG_SYSFS >-/* >- * These sysfs routines show a nice distribution of how many zbpg's are >- * currently (and have ever been placed) in each unbuddied list. It's fun >- * to watch but can probably go away before final merge. >- */ >-static int zbud_show_unbuddied_list_counts(char *buf) >-{ >- int i; >- char *p = buf; >- >- for (i = 0; i < NCHUNKS - 1; i++) >- p += sprintf(p, "%u ", zbud_unbuddied[i].count); >- p += sprintf(p, "%d\n", zbud_unbuddied[i].count); >- return p - buf; >-} >- >-static int zbud_show_cumul_chunk_counts(char *buf) >-{ >- unsigned long i, chunks = 0, total_chunks = 0, sum_total_chunks = 0; >- unsigned long total_chunks_lte_21 = 0, total_chunks_lte_32 = 0; >- unsigned long total_chunks_lte_42 = 0; >- char *p = buf; >- >- for (i = 0; i < NCHUNKS; i++) { >- p += sprintf(p, "%lu ", zbud_cumul_chunk_counts[i]); >- chunks += zbud_cumul_chunk_counts[i]; >- total_chunks += zbud_cumul_chunk_counts[i]; >- sum_total_chunks += i * zbud_cumul_chunk_counts[i]; >- if (i == 21) >- total_chunks_lte_21 = total_chunks; >- if (i == 32) >- total_chunks_lte_32 = total_chunks; >- if (i == 42) >- total_chunks_lte_42 = total_chunks; >- } >- p += sprintf(p, "<=21:%lu <=32:%lu <=42:%lu, mean:%lu\n", >- total_chunks_lte_21, total_chunks_lte_32, total_chunks_lte_42, >- chunks == 0 ? 0 : sum_total_chunks / chunks); >- return p - buf; >-} >-#endif >- >-/********** >- * This "zv" PAM implementation combines the TLSF-based xvMalloc >- * with lzo1x compression to maximize the amount of data that can >- * be packed into a physical page. >- * >- * Zv represents a PAM page with the index and object (plus a "size" value >- * necessary for decompression) immediately preceding the compressed data. >- */ >- >-#define ZVH_SENTINEL 0x43214321 >- >-struct zv_hdr { >- uint32_t pool_id; >- struct tmem_oid oid; >- uint32_t index; >- DECL_SENTINEL >-}; >- >-static const int zv_max_page_size = (PAGE_SIZE / 8) * 7; >- >-static struct zv_hdr *zv_create(struct xv_pool *xvpool, uint32_t pool_id, >- struct tmem_oid *oid, uint32_t index, >- void *cdata, unsigned clen) >-{ >- struct page *page; >- struct zv_hdr *zv = NULL; >- uint32_t offset; >- int ret; >- >- BUG_ON(!irqs_disabled()); >- ret = xv_malloc(xvpool, clen + sizeof(struct zv_hdr), >- &page, &offset, ZCACHE_GFP_MASK); >- if (unlikely(ret)) >- goto out; >- zv = kmap_atomic(page, KM_USER0) + offset; >- zv->index = index; >- zv->oid = *oid; >- zv->pool_id = pool_id; >- SET_SENTINEL(zv, ZVH); >- memcpy((char *)zv + sizeof(struct zv_hdr), cdata, clen); >- kunmap_atomic(zv, KM_USER0); >-out: >- return zv; >-} >- >-static void zv_free(struct xv_pool *xvpool, struct zv_hdr *zv) >-{ >- unsigned long flags; >- struct page *page; >- uint32_t offset; >- uint16_t size; >- >- ASSERT_SENTINEL(zv, ZVH); >- size = xv_get_object_size(zv) - sizeof(*zv); >- BUG_ON(size == 0 || size > zv_max_page_size); >- INVERT_SENTINEL(zv, ZVH); >- page = virt_to_page(zv); >- offset = (unsigned long)zv & ~PAGE_MASK; >- local_irq_save(flags); >- xv_free(xvpool, page, offset); >- local_irq_restore(flags); >-} >- >-static void zv_decompress(struct page *page, struct zv_hdr *zv) >-{ >- size_t clen = PAGE_SIZE; >- char *to_va; >- unsigned size; >- int ret; >- >- ASSERT_SENTINEL(zv, ZVH); >- size = xv_get_object_size(zv) - sizeof(*zv); >- BUG_ON(size == 0 || size > zv_max_page_size); >- to_va = kmap_atomic(page, KM_USER0); >- ret = lzo1x_decompress_safe((char *)zv + sizeof(*zv), >- size, to_va, &clen); >- kunmap_atomic(to_va, KM_USER0); >- BUG_ON(ret != LZO_E_OK); >- BUG_ON(clen != PAGE_SIZE); >-} >- >-/* >- * zcache core code starts here >- */ >- >-/* useful stats not collected by cleancache or frontswap */ >-static unsigned long zcache_flush_total; >-static unsigned long zcache_flush_found; >-static unsigned long zcache_flobj_total; >-static unsigned long zcache_flobj_found; >-static unsigned long zcache_failed_eph_puts; >-static unsigned long zcache_failed_pers_puts; >- >-#define MAX_POOLS_PER_CLIENT 16 >- >-static struct { >- struct tmem_pool *tmem_pools[MAX_POOLS_PER_CLIENT]; >- struct xv_pool *xvpool; >-} zcache_client; >- >-/* >- * Tmem operations assume the poolid implies the invoking client. >- * Zcache only has one client (the kernel itself), so translate >- * the poolid into the tmem_pool allocated for it. A KVM version >- * of zcache would have one client per guest and each client might >- * have a poolid==N. >- */ >-static struct tmem_pool *zcache_get_pool_by_id(uint32_t poolid) >-{ >- struct tmem_pool *pool = NULL; >- >- if (poolid >= 0) { >- pool = zcache_client.tmem_pools[poolid]; >- if (pool != NULL) >- atomic_inc(&pool->refcount); >- } >- return pool; >-} >- >-static void zcache_put_pool(struct tmem_pool *pool) >-{ >- if (pool != NULL) >- atomic_dec(&pool->refcount); >-} >- >-/* counters for debugging */ >-static unsigned long zcache_failed_get_free_pages; >-static unsigned long zcache_failed_alloc; >-static unsigned long zcache_put_to_flush; >-static unsigned long zcache_aborted_preload; >-static unsigned long zcache_aborted_shrink; >- >-/* >- * Ensure that memory allocation requests in zcache don't result >- * in direct reclaim requests via the shrinker, which would cause >- * an infinite loop. Maybe a GFP flag would be better? >- */ >-static DEFINE_SPINLOCK(zcache_direct_reclaim_lock); >- >-/* >- * for now, used named slabs so can easily track usage; later can >- * either just use kmalloc, or perhaps add a slab-like allocator >- * to more carefully manage total memory utilization >- */ >-static struct kmem_cache *zcache_objnode_cache; >-static struct kmem_cache *zcache_obj_cache; >-static atomic_t zcache_curr_obj_count = ATOMIC_INIT(0); >-static unsigned long zcache_curr_obj_count_max; >-static atomic_t zcache_curr_objnode_count = ATOMIC_INIT(0); >-static unsigned long zcache_curr_objnode_count_max; >- >-/* >- * to avoid memory allocation recursion (e.g. due to direct reclaim), we >- * preload all necessary data structures so the hostops callbacks never >- * actually do a malloc >- */ >-struct zcache_preload { >- void *page; >- struct tmem_obj *obj; >- int nr; >- struct tmem_objnode *objnodes[OBJNODE_TREE_MAX_PATH]; >-}; >-static DEFINE_PER_CPU(struct zcache_preload, zcache_preloads) = { 0, }; >- >-static int zcache_do_preload(struct tmem_pool *pool) >-{ >- struct zcache_preload *kp; >- struct tmem_objnode *objnode; >- struct tmem_obj *obj; >- void *page; >- int ret = -ENOMEM; >- >- if (unlikely(zcache_objnode_cache == NULL)) >- goto out; >- if (unlikely(zcache_obj_cache == NULL)) >- goto out; >- if (!spin_trylock(&zcache_direct_reclaim_lock)) { >- zcache_aborted_preload++; >- goto out; >- } >- preempt_disable(); >- kp = &__get_cpu_var(zcache_preloads); >- while (kp->nr < ARRAY_SIZE(kp->objnodes)) { >- preempt_enable_no_resched(); >- objnode = kmem_cache_alloc(zcache_objnode_cache, >- ZCACHE_GFP_MASK); >- if (unlikely(objnode == NULL)) { >- zcache_failed_alloc++; >- goto unlock_out; >- } >- preempt_disable(); >- kp = &__get_cpu_var(zcache_preloads); >- if (kp->nr < ARRAY_SIZE(kp->objnodes)) >- kp->objnodes[kp->nr++] = objnode; >- else >- kmem_cache_free(zcache_objnode_cache, objnode); >- } >- preempt_enable_no_resched(); >- obj = kmem_cache_alloc(zcache_obj_cache, ZCACHE_GFP_MASK); >- if (unlikely(obj == NULL)) { >- zcache_failed_alloc++; >- goto unlock_out; >- } >- page = (void *)__get_free_page(ZCACHE_GFP_MASK); >- if (unlikely(page == NULL)) { >- zcache_failed_get_free_pages++; >- kmem_cache_free(zcache_obj_cache, obj); >- goto unlock_out; >- } >- preempt_disable(); >- kp = &__get_cpu_var(zcache_preloads); >- if (kp->obj == NULL) >- kp->obj = obj; >- else >- kmem_cache_free(zcache_obj_cache, obj); >- if (kp->page == NULL) >- kp->page = page; >- else >- free_page((unsigned long)page); >- ret = 0; >-unlock_out: >- spin_unlock(&zcache_direct_reclaim_lock); >-out: >- return ret; >-} >- >-static void *zcache_get_free_page(void) >-{ >- struct zcache_preload *kp; >- void *page; >- >- kp = &__get_cpu_var(zcache_preloads); >- page = kp->page; >- BUG_ON(page == NULL); >- kp->page = NULL; >- return page; >-} >- >-static void zcache_free_page(void *p) >-{ >- free_page((unsigned long)p); >-} >- >-/* >- * zcache implementation for tmem host ops >- */ >- >-static struct tmem_objnode *zcache_objnode_alloc(struct tmem_pool *pool) >-{ >- struct tmem_objnode *objnode = NULL; >- unsigned long count; >- struct zcache_preload *kp; >- >- kp = &__get_cpu_var(zcache_preloads); >- if (kp->nr <= 0) >- goto out; >- objnode = kp->objnodes[kp->nr - 1]; >- BUG_ON(objnode == NULL); >- kp->objnodes[kp->nr - 1] = NULL; >- kp->nr--; >- count = atomic_inc_return(&zcache_curr_objnode_count); >- if (count > zcache_curr_objnode_count_max) >- zcache_curr_objnode_count_max = count; >-out: >- return objnode; >-} >- >-static void zcache_objnode_free(struct tmem_objnode *objnode, >- struct tmem_pool *pool) >-{ >- atomic_dec(&zcache_curr_objnode_count); >- BUG_ON(atomic_read(&zcache_curr_objnode_count) < 0); >- kmem_cache_free(zcache_objnode_cache, objnode); >-} >- >-static struct tmem_obj *zcache_obj_alloc(struct tmem_pool *pool) >-{ >- struct tmem_obj *obj = NULL; >- unsigned long count; >- struct zcache_preload *kp; >- >- kp = &__get_cpu_var(zcache_preloads); >- obj = kp->obj; >- BUG_ON(obj == NULL); >- kp->obj = NULL; >- count = atomic_inc_return(&zcache_curr_obj_count); >- if (count > zcache_curr_obj_count_max) >- zcache_curr_obj_count_max = count; >- return obj; >-} >- >-static void zcache_obj_free(struct tmem_obj *obj, struct tmem_pool *pool) >-{ >- atomic_dec(&zcache_curr_obj_count); >- BUG_ON(atomic_read(&zcache_curr_obj_count) < 0); >- kmem_cache_free(zcache_obj_cache, obj); >-} >- >-static struct tmem_hostops zcache_hostops = { >- .obj_alloc = zcache_obj_alloc, >- .obj_free = zcache_obj_free, >- .objnode_alloc = zcache_objnode_alloc, >- .objnode_free = zcache_objnode_free, >-}; >- >-/* >- * zcache implementations for PAM page descriptor ops >- */ >- >-static atomic_t zcache_curr_eph_pampd_count = ATOMIC_INIT(0); >-static unsigned long zcache_curr_eph_pampd_count_max; >-static atomic_t zcache_curr_pers_pampd_count = ATOMIC_INIT(0); >-static unsigned long zcache_curr_pers_pampd_count_max; >- >-/* forward reference */ >-static int zcache_compress(struct page *from, void **out_va, size_t *out_len); >- >-static void *zcache_pampd_create(struct tmem_pool *pool, struct tmem_oid *oid, >- uint32_t index, struct page *page) >-{ >- void *pampd = NULL, *cdata; >- size_t clen; >- int ret; >- bool ephemeral = is_ephemeral(pool); >- unsigned long count; >- >- if (ephemeral) { >- ret = zcache_compress(page, &cdata, &clen); >- if (ret == 0) >- >- goto out; >- if (clen == 0 || clen > zbud_max_buddy_size()) { >- zcache_compress_poor++; >- goto out; >- } >- pampd = (void *)zbud_create(pool->pool_id, oid, index, >- page, cdata, clen); >- if (pampd != NULL) { >- count = atomic_inc_return(&zcache_curr_eph_pampd_count); >- if (count > zcache_curr_eph_pampd_count_max) >- zcache_curr_eph_pampd_count_max = count; >- } >- } else { >- /* >- * FIXME: This is all the "policy" there is for now. >- * 3/4 totpages should allow ~37% of RAM to be filled with >- * compressed frontswap pages >- */ >- if (atomic_read(&zcache_curr_pers_pampd_count) > >- 3 * totalram_pages / 4) >- goto out; >- ret = zcache_compress(page, &cdata, &clen); >- if (ret == 0) >- goto out; >- if (clen > zv_max_page_size) { >- zcache_compress_poor++; >- goto out; >- } >- pampd = (void *)zv_create(zcache_client.xvpool, pool->pool_id, >- oid, index, cdata, clen); >- if (pampd == NULL) >- goto out; >- count = atomic_inc_return(&zcache_curr_pers_pampd_count); >- if (count > zcache_curr_pers_pampd_count_max) >- zcache_curr_pers_pampd_count_max = count; >- } >-out: >- return pampd; >-} >- >-/* >- * fill the pageframe corresponding to the struct page with the data >- * from the passed pampd >- */ >-static int zcache_pampd_get_data(struct page *page, void *pampd, >- struct tmem_pool *pool) >-{ >- int ret = 0; >- >- if (is_ephemeral(pool)) >- ret = zbud_decompress(page, pampd); >- else >- zv_decompress(page, pampd); >- return ret; >-} >- >-/* >- * free the pampd and remove it from any zcache lists >- * pampd must no longer be pointed to from any tmem data structures! >- */ >-static void zcache_pampd_free(void *pampd, struct tmem_pool *pool) >-{ >- if (is_ephemeral(pool)) { >- zbud_free_and_delist((struct zbud_hdr *)pampd); >- atomic_dec(&zcache_curr_eph_pampd_count); >- BUG_ON(atomic_read(&zcache_curr_eph_pampd_count) < 0); >- } else { >- zv_free(zcache_client.xvpool, (struct zv_hdr *)pampd); >- atomic_dec(&zcache_curr_pers_pampd_count); >- BUG_ON(atomic_read(&zcache_curr_pers_pampd_count) < 0); >- } >-} >- >-static struct tmem_pamops zcache_pamops = { >- .create = zcache_pampd_create, >- .get_data = zcache_pampd_get_data, >- .free = zcache_pampd_free, >-}; >- >-/* >- * zcache compression/decompression and related per-cpu stuff >- */ >- >-#define LZO_WORKMEM_BYTES LZO1X_1_MEM_COMPRESS >-#define LZO_DSTMEM_PAGE_ORDER 1 >-static DEFINE_PER_CPU(unsigned char *, zcache_workmem); >-static DEFINE_PER_CPU(unsigned char *, zcache_dstmem); >- >-static int zcache_compress(struct page *from, void **out_va, size_t *out_len) >-{ >- int ret = 0; >- unsigned char *dmem = __get_cpu_var(zcache_dstmem); >- unsigned char *wmem = __get_cpu_var(zcache_workmem); >- char *from_va; >- >- BUG_ON(!irqs_disabled()); >- if (unlikely(dmem == NULL || wmem == NULL)) >- goto out; /* no buffer, so can't compress */ >- from_va = kmap_atomic(from, KM_USER0); >- mb(); >- ret = lzo1x_1_compress(from_va, PAGE_SIZE, dmem, out_len, wmem); >- BUG_ON(ret != LZO_E_OK); >- *out_va = dmem; >- kunmap_atomic(from_va, KM_USER0); >- ret = 1; >-out: >- return ret; >-} >- >- >-static int zcache_cpu_notifier(struct notifier_block *nb, >- unsigned long action, void *pcpu) >-{ >- int cpu = (long)pcpu; >- struct zcache_preload *kp; >- >- switch (action) { >- case CPU_UP_PREPARE: >- per_cpu(zcache_dstmem, cpu) = (void *)__get_free_pages( >- GFP_KERNEL | __GFP_REPEAT, >- LZO_DSTMEM_PAGE_ORDER), >- per_cpu(zcache_workmem, cpu) = >- kzalloc(LZO1X_MEM_COMPRESS, >- GFP_KERNEL | __GFP_REPEAT); >- break; >- case CPU_DEAD: >- case CPU_UP_CANCELED: >- free_pages((unsigned long)per_cpu(zcache_dstmem, cpu), >- LZO_DSTMEM_PAGE_ORDER); >- per_cpu(zcache_dstmem, cpu) = NULL; >- kfree(per_cpu(zcache_workmem, cpu)); >- per_cpu(zcache_workmem, cpu) = NULL; >- kp = &per_cpu(zcache_preloads, cpu); >- while (kp->nr) { >- kmem_cache_free(zcache_objnode_cache, >- kp->objnodes[kp->nr - 1]); >- kp->objnodes[kp->nr - 1] = NULL; >- kp->nr--; >- } >- kmem_cache_free(zcache_obj_cache, kp->obj); >- free_page((unsigned long)kp->page); >- break; >- default: >- break; >- } >- return NOTIFY_OK; >-} >- >-static struct notifier_block zcache_cpu_notifier_block = { >- .notifier_call = zcache_cpu_notifier >-}; >- >-#ifdef CONFIG_SYSFS >-#define ZCACHE_SYSFS_RO(_name) \ >- static ssize_t zcache_##_name##_show(struct kobject *kobj, \ >- struct kobj_attribute *attr, char *buf) \ >- { \ >- return sprintf(buf, "%lu\n", zcache_##_name); \ >- } \ >- static struct kobj_attribute zcache_##_name##_attr = { \ >- .attr = { .name = __stringify(_name), .mode = 0444 }, \ >- .show = zcache_##_name##_show, \ >- } >- >-#define ZCACHE_SYSFS_RO_ATOMIC(_name) \ >- static ssize_t zcache_##_name##_show(struct kobject *kobj, \ >- struct kobj_attribute *attr, char *buf) \ >- { \ >- return sprintf(buf, "%d\n", atomic_read(&zcache_##_name)); \ >- } \ >- static struct kobj_attribute zcache_##_name##_attr = { \ >- .attr = { .name = __stringify(_name), .mode = 0444 }, \ >- .show = zcache_##_name##_show, \ >- } >- >-#define ZCACHE_SYSFS_RO_CUSTOM(_name, _func) \ >- static ssize_t zcache_##_name##_show(struct kobject *kobj, \ >- struct kobj_attribute *attr, char *buf) \ >- { \ >- return _func(buf); \ >- } \ >- static struct kobj_attribute zcache_##_name##_attr = { \ >- .attr = { .name = __stringify(_name), .mode = 0444 }, \ >- .show = zcache_##_name##_show, \ >- } >- >-ZCACHE_SYSFS_RO(curr_obj_count_max); >-ZCACHE_SYSFS_RO(curr_objnode_count_max); >-ZCACHE_SYSFS_RO(flush_total); >-ZCACHE_SYSFS_RO(flush_found); >-ZCACHE_SYSFS_RO(flobj_total); >-ZCACHE_SYSFS_RO(flobj_found); >-ZCACHE_SYSFS_RO(failed_eph_puts); >-ZCACHE_SYSFS_RO(failed_pers_puts); >-ZCACHE_SYSFS_RO(zbud_curr_zbytes); >-ZCACHE_SYSFS_RO(zbud_cumul_zpages); >-ZCACHE_SYSFS_RO(zbud_cumul_zbytes); >-ZCACHE_SYSFS_RO(zbud_buddied_count); >-ZCACHE_SYSFS_RO(zbpg_unused_list_count); >-ZCACHE_SYSFS_RO(evicted_raw_pages); >-ZCACHE_SYSFS_RO(evicted_unbuddied_pages); >-ZCACHE_SYSFS_RO(evicted_buddied_pages); >-ZCACHE_SYSFS_RO(failed_get_free_pages); >-ZCACHE_SYSFS_RO(failed_alloc); >-ZCACHE_SYSFS_RO(put_to_flush); >-ZCACHE_SYSFS_RO(aborted_preload); >-ZCACHE_SYSFS_RO(aborted_shrink); >-ZCACHE_SYSFS_RO(compress_poor); >-ZCACHE_SYSFS_RO_ATOMIC(zbud_curr_raw_pages); >-ZCACHE_SYSFS_RO_ATOMIC(zbud_curr_zpages); >-ZCACHE_SYSFS_RO_ATOMIC(curr_obj_count); >-ZCACHE_SYSFS_RO_ATOMIC(curr_objnode_count); >-ZCACHE_SYSFS_RO_CUSTOM(zbud_unbuddied_list_counts, >- zbud_show_unbuddied_list_counts); >-ZCACHE_SYSFS_RO_CUSTOM(zbud_cumul_chunk_counts, >- zbud_show_cumul_chunk_counts); >- >-static struct attribute *zcache_attrs[] = { >- &zcache_curr_obj_count_attr.attr, >- &zcache_curr_obj_count_max_attr.attr, >- &zcache_curr_objnode_count_attr.attr, >- &zcache_curr_objnode_count_max_attr.attr, >- &zcache_flush_total_attr.attr, >- &zcache_flobj_total_attr.attr, >- &zcache_flush_found_attr.attr, >- &zcache_flobj_found_attr.attr, >- &zcache_failed_eph_puts_attr.attr, >- &zcache_failed_pers_puts_attr.attr, >- &zcache_compress_poor_attr.attr, >- &zcache_zbud_curr_raw_pages_attr.attr, >- &zcache_zbud_curr_zpages_attr.attr, >- &zcache_zbud_curr_zbytes_attr.attr, >- &zcache_zbud_cumul_zpages_attr.attr, >- &zcache_zbud_cumul_zbytes_attr.attr, >- &zcache_zbud_buddied_count_attr.attr, >- &zcache_zbpg_unused_list_count_attr.attr, >- &zcache_evicted_raw_pages_attr.attr, >- &zcache_evicted_unbuddied_pages_attr.attr, >- &zcache_evicted_buddied_pages_attr.attr, >- &zcache_failed_get_free_pages_attr.attr, >- &zcache_failed_alloc_attr.attr, >- &zcache_put_to_flush_attr.attr, >- &zcache_aborted_preload_attr.attr, >- &zcache_aborted_shrink_attr.attr, >- &zcache_zbud_unbuddied_list_counts_attr.attr, >- &zcache_zbud_cumul_chunk_counts_attr.attr, >- NULL, >-}; >- >-static struct attribute_group zcache_attr_group = { >- .attrs = zcache_attrs, >- .name = "zcache", >-}; >- >-#endif /* CONFIG_SYSFS */ >-/* >- * When zcache is disabled ("frozen"), pools can be created and destroyed, >- * but all puts (and thus all other operations that require memory allocation) >- * must fail. If zcache is unfrozen, accepts puts, then frozen again, >- * data consistency requires all puts while frozen to be converted into >- * flushes. >- */ >-static bool zcache_freeze; >- >-/* >- * zcache shrinker interface (only useful for ephemeral pages, so zbud only) >- */ >-static int shrink_zcache_memory(struct shrinker *shrink, >- struct shrink_control *sc) >-{ >- int ret = -1; >- int nr = sc->nr_to_scan; >- gfp_t gfp_mask = sc->gfp_mask; >- >- if (nr >= 0) { >- if (!(gfp_mask & __GFP_FS)) >- /* does this case really need to be skipped? */ >- goto out; >- if (spin_trylock(&zcache_direct_reclaim_lock)) { >- zbud_evict_pages(nr); >- spin_unlock(&zcache_direct_reclaim_lock); >- } else >- zcache_aborted_shrink++; >- } >- ret = (int)atomic_read(&zcache_zbud_curr_raw_pages); >-out: >- return ret; >-} >- >-static struct shrinker zcache_shrinker = { >- .shrink = shrink_zcache_memory, >- .seeks = DEFAULT_SEEKS, >-}; >- >-/* >- * zcache shims between cleancache/frontswap ops and tmem >- */ >- >-static int zcache_put_page(int pool_id, struct tmem_oid *oidp, >- uint32_t index, struct page *page) >-{ >- struct tmem_pool *pool; >- int ret = -1; >- >- BUG_ON(!irqs_disabled()); >- pool = zcache_get_pool_by_id(pool_id); >- if (unlikely(pool == NULL)) >- goto out; >- if (!zcache_freeze && zcache_do_preload(pool) == 0) { >- /* preload does preempt_disable on success */ >- ret = tmem_put(pool, oidp, index, page); >- if (ret < 0) { >- if (is_ephemeral(pool)) >- zcache_failed_eph_puts++; >- else >- zcache_failed_pers_puts++; >- } >- zcache_put_pool(pool); >- preempt_enable_no_resched(); >- } else { >- zcache_put_to_flush++; >- if (atomic_read(&pool->obj_count) > 0) >- /* the put fails whether the flush succeeds or not */ >- (void)tmem_flush_page(pool, oidp, index); >- zcache_put_pool(pool); >- } >-out: >- return ret; >-} >- >-static int zcache_get_page(int pool_id, struct tmem_oid *oidp, >- uint32_t index, struct page *page) >-{ >- struct tmem_pool *pool; >- int ret = -1; >- unsigned long flags; >- >- local_irq_save(flags); >- pool = zcache_get_pool_by_id(pool_id); >- if (likely(pool != NULL)) { >- if (atomic_read(&pool->obj_count) > 0) >- ret = tmem_get(pool, oidp, index, page); >- zcache_put_pool(pool); >- } >- local_irq_restore(flags); >- return ret; >-} >- >-static int zcache_flush_page(int pool_id, struct tmem_oid *oidp, uint32_t index) >-{ >- struct tmem_pool *pool; >- int ret = -1; >- unsigned long flags; >- >- local_irq_save(flags); >- zcache_flush_total++; >- pool = zcache_get_pool_by_id(pool_id); >- if (likely(pool != NULL)) { >- if (atomic_read(&pool->obj_count) > 0) >- ret = tmem_flush_page(pool, oidp, index); >- zcache_put_pool(pool); >- } >- if (ret >= 0) >- zcache_flush_found++; >- local_irq_restore(flags); >- return ret; >-} >- >-static int zcache_flush_object(int pool_id, struct tmem_oid *oidp) >-{ >- struct tmem_pool *pool; >- int ret = -1; >- unsigned long flags; >- >- local_irq_save(flags); >- zcache_flobj_total++; >- pool = zcache_get_pool_by_id(pool_id); >- if (likely(pool != NULL)) { >- if (atomic_read(&pool->obj_count) > 0) >- ret = tmem_flush_object(pool, oidp); >- zcache_put_pool(pool); >- } >- if (ret >= 0) >- zcache_flobj_found++; >- local_irq_restore(flags); >- return ret; >-} >- >-static int zcache_destroy_pool(int pool_id) >-{ >- struct tmem_pool *pool = NULL; >- int ret = -1; >- >- if (pool_id < 0) >- goto out; >- pool = zcache_client.tmem_pools[pool_id]; >- if (pool == NULL) >- goto out; >- zcache_client.tmem_pools[pool_id] = NULL; >- /* wait for pool activity on other cpus to quiesce */ >- while (atomic_read(&pool->refcount) != 0) >- ; >- local_bh_disable(); >- ret = tmem_destroy_pool(pool); >- local_bh_enable(); >- kfree(pool); >- pr_info("zcache: destroyed pool id=%d\n", pool_id); >-out: >- return ret; >-} >- >-static int zcache_new_pool(uint32_t flags) >-{ >- int poolid = -1; >- struct tmem_pool *pool; >- >- pool = kmalloc(sizeof(struct tmem_pool), GFP_KERNEL); >- if (pool == NULL) { >- pr_info("zcache: pool creation failed: out of memory\n"); >- goto out; >- } >- >- for (poolid = 0; poolid < MAX_POOLS_PER_CLIENT; poolid++) >- if (zcache_client.tmem_pools[poolid] == NULL) >- break; >- if (poolid >= MAX_POOLS_PER_CLIENT) { >- pr_info("zcache: pool creation failed: max exceeded\n"); >- kfree(pool); >- poolid = -1; >- goto out; >- } >- atomic_set(&pool->refcount, 0); >- pool->client = &zcache_client; >- pool->pool_id = poolid; >- tmem_new_pool(pool, flags); >- zcache_client.tmem_pools[poolid] = pool; >- pr_info("zcache: created %s tmem pool, id=%d\n", >- flags & TMEM_POOL_PERSIST ? "persistent" : "ephemeral", >- poolid); >-out: >- return poolid; >-} >- >-/********** >- * Two kernel functionalities currently can be layered on top of tmem. >- * These are "cleancache" which is used as a second-chance cache for clean >- * page cache pages; and "frontswap" which is used for swap pages >- * to avoid writes to disk. A generic "shim" is provided here for each >- * to translate in-kernel semantics to zcache semantics. >- */ >- >-#ifdef CONFIG_CLEANCACHE >-static void zcache_cleancache_put_page(int pool_id, >- struct cleancache_filekey key, >- pgoff_t index, struct page *page) >-{ >- u32 ind = (u32) index; >- struct tmem_oid oid = *(struct tmem_oid *)&key; >- >- if (likely(ind == index)) >- (void)zcache_put_page(pool_id, &oid, index, page); >-} >- >-static int zcache_cleancache_get_page(int pool_id, >- struct cleancache_filekey key, >- pgoff_t index, struct page *page) >-{ >- u32 ind = (u32) index; >- struct tmem_oid oid = *(struct tmem_oid *)&key; >- int ret = -1; >- >- if (likely(ind == index)) >- ret = zcache_get_page(pool_id, &oid, index, page); >- return ret; >-} >- >-static void zcache_cleancache_flush_page(int pool_id, >- struct cleancache_filekey key, >- pgoff_t index) >-{ >- u32 ind = (u32) index; >- struct tmem_oid oid = *(struct tmem_oid *)&key; >- >- if (likely(ind == index)) >- (void)zcache_flush_page(pool_id, &oid, ind); >-} >- >-static void zcache_cleancache_flush_inode(int pool_id, >- struct cleancache_filekey key) >-{ >- struct tmem_oid oid = *(struct tmem_oid *)&key; >- >- (void)zcache_flush_object(pool_id, &oid); >-} >- >-static void zcache_cleancache_flush_fs(int pool_id) >-{ >- if (pool_id >= 0) >- (void)zcache_destroy_pool(pool_id); >-} >- >-static int zcache_cleancache_init_fs(size_t pagesize) >-{ >- BUG_ON(sizeof(struct cleancache_filekey) != >- sizeof(struct tmem_oid)); >- BUG_ON(pagesize != PAGE_SIZE); >- return zcache_new_pool(0); >-} >- >-static int zcache_cleancache_init_shared_fs(char *uuid, size_t pagesize) >-{ >- /* shared pools are unsupported and map to private */ >- BUG_ON(sizeof(struct cleancache_filekey) != >- sizeof(struct tmem_oid)); >- BUG_ON(pagesize != PAGE_SIZE); >- return zcache_new_pool(0); >-} >- >-static struct cleancache_ops zcache_cleancache_ops = { >- .put_page = zcache_cleancache_put_page, >- .get_page = zcache_cleancache_get_page, >- .flush_page = zcache_cleancache_flush_page, >- .flush_inode = zcache_cleancache_flush_inode, >- .flush_fs = zcache_cleancache_flush_fs, >- .init_shared_fs = zcache_cleancache_init_shared_fs, >- .init_fs = zcache_cleancache_init_fs >-}; >- >-struct cleancache_ops zcache_cleancache_register_ops(void) >-{ >- struct cleancache_ops old_ops = >- cleancache_register_ops(&zcache_cleancache_ops); >- >- return old_ops; >-} >-#endif >- >-#ifdef CONFIG_FRONTSWAP >-/* a single tmem poolid is used for all frontswap "types" (swapfiles) */ >-static int zcache_frontswap_poolid = -1; >- >-/* >- * Swizzling increases objects per swaptype, increasing tmem concurrency >- * for heavy swaploads. Later, larger nr_cpus -> larger SWIZ_BITS >- */ >-#define SWIZ_BITS 4 >-#define SWIZ_MASK ((1 << SWIZ_BITS) - 1) >-#define _oswiz(_type, _ind) ((_type << SWIZ_BITS) | (_ind & SWIZ_MASK)) >-#define iswiz(_ind) (_ind >> SWIZ_BITS) >- >-static inline struct tmem_oid oswiz(unsigned type, u32 ind) >-{ >- struct tmem_oid oid = { .oid = { 0 } }; >- oid.oid[0] = _oswiz(type, ind); >- return oid; >-} >- >-static int zcache_frontswap_put_page(unsigned type, pgoff_t offset, >- struct page *page) >-{ >- u64 ind64 = (u64)offset; >- u32 ind = (u32)offset; >- struct tmem_oid oid = oswiz(type, ind); >- int ret = -1; >- unsigned long flags; >- >- BUG_ON(!PageLocked(page)); >- if (likely(ind64 == ind)) { >- local_irq_save(flags); >- ret = zcache_put_page(zcache_frontswap_poolid, &oid, >- iswiz(ind), page); >- local_irq_restore(flags); >- } >- return ret; >-} >- >-/* returns 0 if the page was successfully gotten from frontswap, -1 if >- * was not present (should never happen!) */ >-static int zcache_frontswap_get_page(unsigned type, pgoff_t offset, >- struct page *page) >-{ >- u64 ind64 = (u64)offset; >- u32 ind = (u32)offset; >- struct tmem_oid oid = oswiz(type, ind); >- int ret = -1; >- >- BUG_ON(!PageLocked(page)); >- if (likely(ind64 == ind)) >- ret = zcache_get_page(zcache_frontswap_poolid, &oid, >- iswiz(ind), page); >- return ret; >-} >- >-/* flush a single page from frontswap */ >-static void zcache_frontswap_flush_page(unsigned type, pgoff_t offset) >-{ >- u64 ind64 = (u64)offset; >- u32 ind = (u32)offset; >- struct tmem_oid oid = oswiz(type, ind); >- >- if (likely(ind64 == ind)) >- (void)zcache_flush_page(zcache_frontswap_poolid, &oid, >- iswiz(ind)); >-} >- >-/* flush all pages from the passed swaptype */ >-static void zcache_frontswap_flush_area(unsigned type) >-{ >- struct tmem_oid oid; >- int ind; >- >- for (ind = SWIZ_MASK; ind >= 0; ind--) { >- oid = oswiz(type, ind); >- (void)zcache_flush_object(zcache_frontswap_poolid, &oid); >- } >-} >- >-static void zcache_frontswap_init(unsigned ignored) >-{ >- /* a single tmem poolid is used for all frontswap "types" (swapfiles) */ >- if (zcache_frontswap_poolid < 0) >- zcache_frontswap_poolid = zcache_new_pool(TMEM_POOL_PERSIST); >-} >- >-static struct frontswap_ops zcache_frontswap_ops = { >- .put_page = zcache_frontswap_put_page, >- .get_page = zcache_frontswap_get_page, >- .flush_page = zcache_frontswap_flush_page, >- .flush_area = zcache_frontswap_flush_area, >- .init = zcache_frontswap_init >-}; >- >-struct frontswap_ops zcache_frontswap_register_ops(void) >-{ >- struct frontswap_ops old_ops = >- frontswap_register_ops(&zcache_frontswap_ops); >- >- return old_ops; >-} >-#endif >- >-/* >- * zcache initialization >- * NOTE FOR NOW zcache MUST BE PROVIDED AS A KERNEL BOOT PARAMETER OR >- * NOTHING HAPPENS! >- */ >- >-static int zcache_enabled; >- >-static int __init enable_zcache(char *s) >-{ >- zcache_enabled = 1; >- return 1; >-} >-__setup("zcache", enable_zcache); >- >-/* allow independent dynamic disabling of cleancache and frontswap */ >- >-static int use_cleancache = 1; >- >-static int __init no_cleancache(char *s) >-{ >- use_cleancache = 0; >- return 1; >-} >- >-__setup("nocleancache", no_cleancache); >- >-static int use_frontswap = 1; >- >-static int __init no_frontswap(char *s) >-{ >- use_frontswap = 0; >- return 1; >-} >- >-__setup("nofrontswap", no_frontswap); >- >-static int __init zcache_init(void) >-{ >-#ifdef CONFIG_SYSFS >- int ret = 0; >- >- ret = sysfs_create_group(mm_kobj, &zcache_attr_group); >- if (ret) { >- pr_err("zcache: can't create sysfs\n"); >- goto out; >- } >-#endif /* CONFIG_SYSFS */ >-#if defined(CONFIG_CLEANCACHE) || defined(CONFIG_FRONTSWAP) >- if (zcache_enabled) { >- unsigned int cpu; >- >- tmem_register_hostops(&zcache_hostops); >- tmem_register_pamops(&zcache_pamops); >- ret = register_cpu_notifier(&zcache_cpu_notifier_block); >- if (ret) { >- pr_err("zcache: can't register cpu notifier\n"); >- goto out; >- } >- for_each_online_cpu(cpu) { >- void *pcpu = (void *)(long)cpu; >- zcache_cpu_notifier(&zcache_cpu_notifier_block, >- CPU_UP_PREPARE, pcpu); >- } >- } >- zcache_objnode_cache = kmem_cache_create("zcache_objnode", >- sizeof(struct tmem_objnode), 0, 0, NULL); >- zcache_obj_cache = kmem_cache_create("zcache_obj", >- sizeof(struct tmem_obj), 0, 0, NULL); >-#endif >-#ifdef CONFIG_CLEANCACHE >- if (zcache_enabled && use_cleancache) { >- struct cleancache_ops old_ops; >- >- zbud_init(); >- register_shrinker(&zcache_shrinker); >- old_ops = zcache_cleancache_register_ops(); >- pr_info("zcache: cleancache enabled using kernel " >- "transcendent memory and compression buddies\n"); >- if (old_ops.init_fs != NULL) >- pr_warning("zcache: cleancache_ops overridden"); >- } >-#endif >-#ifdef CONFIG_FRONTSWAP >- if (zcache_enabled && use_frontswap) { >- struct frontswap_ops old_ops; >- >- zcache_client.xvpool = xv_create_pool(); >- if (zcache_client.xvpool == NULL) { >- pr_err("zcache: can't create xvpool\n"); >- goto out; >- } >- old_ops = zcache_frontswap_register_ops(); >- pr_info("zcache: frontswap enabled using kernel " >- "transcendent memory and xvmalloc\n"); >- if (old_ops.init != NULL) >- pr_warning("ktmem: frontswap_ops overridden"); >- } >-#endif >-out: >- return ret; >-} >- >-module_init(zcache_init) >diff -urN drivers.old//staging/zcache/zcache_drv.c drivers//staging/zcache/zcache_drv.c >--- drivers.old//staging/zcache/zcache_drv.c 1970-01-01 01:00:00.000000000 +0100 >+++ drivers//staging/zcache/zcache_drv.c 2011-07-25 12:02:14.032242244 +0200 >@@ -0,0 +1,1661 @@ >+/* >+ * zcache.c >+ * >+ * Copyright (c) 2010,2011, Dan Magenheimer, Oracle Corp. >+ * Copyright (c) 2010,2011, Nitin Gupta >+ * >+ * Zcache provides an in-kernel "host implementation" for transcendent memory >+ * and, thus indirectly, for cleancache and frontswap. Zcache includes two >+ * page-accessible memory [1] interfaces, both utilizing lzo1x compression: >+ * 1) "compression buddies" ("zbud") is used for ephemeral pages >+ * 2) xvmalloc is used for persistent pages. >+ * Xvmalloc (based on the TLSF allocator) has very low fragmentation >+ * so maximizes space efficiency, while zbud allows pairs (and potentially, >+ * in the future, more than a pair of) compressed pages to be closely linked >+ * so that reclaiming can be done via the kernel's physical-page-oriented >+ * "shrinker" interface. >+ * >+ * [1] For a definition of page-accessible memory (aka PAM), see: >+ * http://marc.info/?l=linux-mm&m=127811271605009 >+ */ >+ >+#include <linux/cpu.h> >+#include <linux/highmem.h> >+#include <linux/list.h> >+#include <linux/lzo.h> >+#include <linux/slab.h> >+#include <linux/spinlock.h> >+#include <linux/types.h> >+#include <linux/atomic.h> >+#include "tmem.h" >+ >+#include "../zram/xvmalloc.h" /* if built in drivers/staging */ >+ >+#if (!defined(CONFIG_CLEANCACHE) && !defined(CONFIG_FRONTSWAP)) >+#error "zcache is useless without CONFIG_CLEANCACHE or CONFIG_FRONTSWAP" >+#endif >+#ifdef CONFIG_CLEANCACHE >+#include <linux/cleancache.h> >+#endif >+#ifdef CONFIG_FRONTSWAP >+#include <linux/frontswap.h> >+#endif >+ >+#if 0 >+/* this is more aggressive but may cause other problems? */ >+#define ZCACHE_GFP_MASK (GFP_ATOMIC | __GFP_NORETRY | __GFP_NOWARN) >+#else >+#define ZCACHE_GFP_MASK \ >+ (__GFP_FS | __GFP_NORETRY | __GFP_NOWARN | __GFP_NOMEMALLOC) >+#endif >+ >+/********** >+ * Compression buddies ("zbud") provides for packing two (or, possibly >+ * in the future, more) compressed ephemeral pages into a single "raw" >+ * (physical) page and tracking them with data structures so that >+ * the raw pages can be easily reclaimed. >+ * >+ * A zbud page ("zbpg") is an aligned page containing a list_head, >+ * a lock, and two "zbud headers". The remainder of the physical >+ * page is divided up into aligned 64-byte "chunks" which contain >+ * the compressed data for zero, one, or two zbuds. Each zbpg >+ * resides on: (1) an "unused list" if it has no zbuds; (2) a >+ * "buddied" list if it is fully populated with two zbuds; or >+ * (3) one of PAGE_SIZE/64 "unbuddied" lists indexed by how many chunks >+ * the one unbuddied zbud uses. The data inside a zbpg cannot be >+ * read or written unless the zbpg's lock is held. >+ */ >+ >+#define ZBH_SENTINEL 0x43214321 >+#define ZBPG_SENTINEL 0xdeadbeef >+ >+#define ZBUD_MAX_BUDS 2 >+ >+struct zbud_hdr { >+ uint32_t pool_id; >+ struct tmem_oid oid; >+ uint32_t index; >+ uint16_t size; /* compressed size in bytes, zero means unused */ >+ DECL_SENTINEL >+}; >+ >+struct zbud_page { >+ struct list_head bud_list; >+ spinlock_t lock; >+ struct zbud_hdr buddy[ZBUD_MAX_BUDS]; >+ DECL_SENTINEL >+ /* followed by NUM_CHUNK aligned CHUNK_SIZE-byte chunks */ >+}; >+ >+#define CHUNK_SHIFT 6 >+#define CHUNK_SIZE (1 << CHUNK_SHIFT) >+#define CHUNK_MASK (~(CHUNK_SIZE-1)) >+#define NCHUNKS (((PAGE_SIZE - sizeof(struct zbud_page)) & \ >+ CHUNK_MASK) >> CHUNK_SHIFT) >+#define MAX_CHUNK (NCHUNKS-1) >+ >+static struct { >+ struct list_head list; >+ unsigned count; >+} zbud_unbuddied[NCHUNKS]; >+/* list N contains pages with N chunks USED and NCHUNKS-N unused */ >+/* element 0 is never used but optimizing that isn't worth it */ >+static unsigned long zbud_cumul_chunk_counts[NCHUNKS]; >+ >+struct list_head zbud_buddied_list; >+static unsigned long zcache_zbud_buddied_count; >+ >+/* protects the buddied list and all unbuddied lists */ >+static DEFINE_SPINLOCK(zbud_budlists_spinlock); >+ >+static LIST_HEAD(zbpg_unused_list); >+static unsigned long zcache_zbpg_unused_list_count; >+ >+/* protects the unused page list */ >+static DEFINE_SPINLOCK(zbpg_unused_list_spinlock); >+ >+static atomic_t zcache_zbud_curr_raw_pages; >+static atomic_t zcache_zbud_curr_zpages; >+static unsigned long zcache_zbud_curr_zbytes; >+static unsigned long zcache_zbud_cumul_zpages; >+static unsigned long zcache_zbud_cumul_zbytes; >+static unsigned long zcache_compress_poor; >+ >+/* forward references */ >+static void *zcache_get_free_page(void); >+static void zcache_free_page(void *p); >+ >+/* >+ * zbud helper functions >+ */ >+ >+static inline unsigned zbud_max_buddy_size(void) >+{ >+ return MAX_CHUNK << CHUNK_SHIFT; >+} >+ >+static inline unsigned zbud_size_to_chunks(unsigned size) >+{ >+ BUG_ON(size == 0 || size > zbud_max_buddy_size()); >+ return (size + CHUNK_SIZE - 1) >> CHUNK_SHIFT; >+} >+ >+static inline int zbud_budnum(struct zbud_hdr *zh) >+{ >+ unsigned offset = (unsigned long)zh & (PAGE_SIZE - 1); >+ struct zbud_page *zbpg = NULL; >+ unsigned budnum = -1U; >+ int i; >+ >+ for (i = 0; i < ZBUD_MAX_BUDS; i++) >+ if (offset == offsetof(typeof(*zbpg), buddy[i])) { >+ budnum = i; >+ break; >+ } >+ BUG_ON(budnum == -1U); >+ return budnum; >+} >+ >+static char *zbud_data(struct zbud_hdr *zh, unsigned size) >+{ >+ struct zbud_page *zbpg; >+ char *p; >+ unsigned budnum; >+ >+ ASSERT_SENTINEL(zh, ZBH); >+ budnum = zbud_budnum(zh); >+ BUG_ON(size == 0 || size > zbud_max_buddy_size()); >+ zbpg = container_of(zh, struct zbud_page, buddy[budnum]); >+ ASSERT_SPINLOCK(&zbpg->lock); >+ p = (char *)zbpg; >+ if (budnum == 0) >+ p += ((sizeof(struct zbud_page) + CHUNK_SIZE - 1) & >+ CHUNK_MASK); >+ else if (budnum == 1) >+ p += PAGE_SIZE - ((size + CHUNK_SIZE - 1) & CHUNK_MASK); >+ return p; >+} >+ >+/* >+ * zbud raw page management >+ */ >+ >+static struct zbud_page *zbud_alloc_raw_page(void) >+{ >+ struct zbud_page *zbpg = NULL; >+ struct zbud_hdr *zh0, *zh1; >+ bool recycled = 0; >+ >+ /* if any pages on the zbpg list, use one */ >+ spin_lock(&zbpg_unused_list_spinlock); >+ if (!list_empty(&zbpg_unused_list)) { >+ zbpg = list_first_entry(&zbpg_unused_list, >+ struct zbud_page, bud_list); >+ list_del_init(&zbpg->bud_list); >+ zcache_zbpg_unused_list_count--; >+ recycled = 1; >+ } >+ spin_unlock(&zbpg_unused_list_spinlock); >+ if (zbpg == NULL) >+ /* none on zbpg list, try to get a kernel page */ >+ zbpg = zcache_get_free_page(); >+ if (likely(zbpg != NULL)) { >+ INIT_LIST_HEAD(&zbpg->bud_list); >+ zh0 = &zbpg->buddy[0]; zh1 = &zbpg->buddy[1]; >+ spin_lock_init(&zbpg->lock); >+ if (recycled) { >+ ASSERT_INVERTED_SENTINEL(zbpg, ZBPG); >+ SET_SENTINEL(zbpg, ZBPG); >+ BUG_ON(zh0->size != 0 || tmem_oid_valid(&zh0->oid)); >+ BUG_ON(zh1->size != 0 || tmem_oid_valid(&zh1->oid)); >+ } else { >+ atomic_inc(&zcache_zbud_curr_raw_pages); >+ INIT_LIST_HEAD(&zbpg->bud_list); >+ SET_SENTINEL(zbpg, ZBPG); >+ zh0->size = 0; zh1->size = 0; >+ tmem_oid_set_invalid(&zh0->oid); >+ tmem_oid_set_invalid(&zh1->oid); >+ } >+ } >+ return zbpg; >+} >+ >+static void zbud_free_raw_page(struct zbud_page *zbpg) >+{ >+ struct zbud_hdr *zh0 = &zbpg->buddy[0], *zh1 = &zbpg->buddy[1]; >+ >+ ASSERT_SENTINEL(zbpg, ZBPG); >+ BUG_ON(!list_empty(&zbpg->bud_list)); >+ ASSERT_SPINLOCK(&zbpg->lock); >+ BUG_ON(zh0->size != 0 || tmem_oid_valid(&zh0->oid)); >+ BUG_ON(zh1->size != 0 || tmem_oid_valid(&zh1->oid)); >+ INVERT_SENTINEL(zbpg, ZBPG); >+ spin_unlock(&zbpg->lock); >+ spin_lock(&zbpg_unused_list_spinlock); >+ list_add(&zbpg->bud_list, &zbpg_unused_list); >+ zcache_zbpg_unused_list_count++; >+ spin_unlock(&zbpg_unused_list_spinlock); >+} >+ >+/* >+ * core zbud handling routines >+ */ >+ >+static unsigned zbud_free(struct zbud_hdr *zh) >+{ >+ unsigned size; >+ >+ ASSERT_SENTINEL(zh, ZBH); >+ BUG_ON(!tmem_oid_valid(&zh->oid)); >+ size = zh->size; >+ BUG_ON(zh->size == 0 || zh->size > zbud_max_buddy_size()); >+ zh->size = 0; >+ tmem_oid_set_invalid(&zh->oid); >+ INVERT_SENTINEL(zh, ZBH); >+ zcache_zbud_curr_zbytes -= size; >+ atomic_dec(&zcache_zbud_curr_zpages); >+ return size; >+} >+ >+static void zbud_free_and_delist(struct zbud_hdr *zh) >+{ >+ unsigned chunks; >+ struct zbud_hdr *zh_other; >+ unsigned budnum = zbud_budnum(zh), size; >+ struct zbud_page *zbpg = >+ container_of(zh, struct zbud_page, buddy[budnum]); >+ >+ spin_lock(&zbpg->lock); >+ if (list_empty(&zbpg->bud_list)) { >+ /* ignore zombie page... see zbud_evict_pages() */ >+ spin_unlock(&zbpg->lock); >+ return; >+ } >+ size = zbud_free(zh); >+ ASSERT_SPINLOCK(&zbpg->lock); >+ zh_other = &zbpg->buddy[(budnum == 0) ? 1 : 0]; >+ if (zh_other->size == 0) { /* was unbuddied: unlist and free */ >+ chunks = zbud_size_to_chunks(size) ; >+ spin_lock(&zbud_budlists_spinlock); >+ BUG_ON(list_empty(&zbud_unbuddied[chunks].list)); >+ list_del_init(&zbpg->bud_list); >+ zbud_unbuddied[chunks].count--; >+ spin_unlock(&zbud_budlists_spinlock); >+ zbud_free_raw_page(zbpg); >+ } else { /* was buddied: move remaining buddy to unbuddied list */ >+ chunks = zbud_size_to_chunks(zh_other->size) ; >+ spin_lock(&zbud_budlists_spinlock); >+ list_del_init(&zbpg->bud_list); >+ zcache_zbud_buddied_count--; >+ list_add_tail(&zbpg->bud_list, &zbud_unbuddied[chunks].list); >+ zbud_unbuddied[chunks].count++; >+ spin_unlock(&zbud_budlists_spinlock); >+ spin_unlock(&zbpg->lock); >+ } >+} >+ >+static struct zbud_hdr *zbud_create(uint32_t pool_id, struct tmem_oid *oid, >+ uint32_t index, struct page *page, >+ void *cdata, unsigned size) >+{ >+ struct zbud_hdr *zh0, *zh1, *zh = NULL; >+ struct zbud_page *zbpg = NULL, *ztmp; >+ unsigned nchunks; >+ char *to; >+ int i, found_good_buddy = 0; >+ >+ nchunks = zbud_size_to_chunks(size) ; >+ for (i = MAX_CHUNK - nchunks + 1; i > 0; i--) { >+ spin_lock(&zbud_budlists_spinlock); >+ if (!list_empty(&zbud_unbuddied[i].list)) { >+ list_for_each_entry_safe(zbpg, ztmp, >+ &zbud_unbuddied[i].list, bud_list) { >+ if (spin_trylock(&zbpg->lock)) { >+ found_good_buddy = i; >+ goto found_unbuddied; >+ } >+ } >+ } >+ spin_unlock(&zbud_budlists_spinlock); >+ } >+ /* didn't find a good buddy, try allocating a new page */ >+ zbpg = zbud_alloc_raw_page(); >+ if (unlikely(zbpg == NULL)) >+ goto out; >+ /* ok, have a page, now compress the data before taking locks */ >+ spin_lock(&zbpg->lock); >+ spin_lock(&zbud_budlists_spinlock); >+ list_add_tail(&zbpg->bud_list, &zbud_unbuddied[nchunks].list); >+ zbud_unbuddied[nchunks].count++; >+ zh = &zbpg->buddy[0]; >+ goto init_zh; >+ >+found_unbuddied: >+ ASSERT_SPINLOCK(&zbpg->lock); >+ zh0 = &zbpg->buddy[0]; zh1 = &zbpg->buddy[1]; >+ BUG_ON(!((zh0->size == 0) ^ (zh1->size == 0))); >+ if (zh0->size != 0) { /* buddy0 in use, buddy1 is vacant */ >+ ASSERT_SENTINEL(zh0, ZBH); >+ zh = zh1; >+ } else if (zh1->size != 0) { /* buddy1 in use, buddy0 is vacant */ >+ ASSERT_SENTINEL(zh1, ZBH); >+ zh = zh0; >+ } else >+ BUG(); >+ list_del_init(&zbpg->bud_list); >+ zbud_unbuddied[found_good_buddy].count--; >+ list_add_tail(&zbpg->bud_list, &zbud_buddied_list); >+ zcache_zbud_buddied_count++; >+ >+init_zh: >+ SET_SENTINEL(zh, ZBH); >+ zh->size = size; >+ zh->index = index; >+ zh->oid = *oid; >+ zh->pool_id = pool_id; >+ /* can wait to copy the data until the list locks are dropped */ >+ spin_unlock(&zbud_budlists_spinlock); >+ >+ to = zbud_data(zh, size); >+ memcpy(to, cdata, size); >+ spin_unlock(&zbpg->lock); >+ zbud_cumul_chunk_counts[nchunks]++; >+ atomic_inc(&zcache_zbud_curr_zpages); >+ zcache_zbud_cumul_zpages++; >+ zcache_zbud_curr_zbytes += size; >+ zcache_zbud_cumul_zbytes += size; >+out: >+ return zh; >+} >+ >+static int zbud_decompress(struct page *page, struct zbud_hdr *zh) >+{ >+ struct zbud_page *zbpg; >+ unsigned budnum = zbud_budnum(zh); >+ size_t out_len = PAGE_SIZE; >+ char *to_va, *from_va; >+ unsigned size; >+ int ret = 0; >+ >+ zbpg = container_of(zh, struct zbud_page, buddy[budnum]); >+ spin_lock(&zbpg->lock); >+ if (list_empty(&zbpg->bud_list)) { >+ /* ignore zombie page... see zbud_evict_pages() */ >+ ret = -EINVAL; >+ goto out; >+ } >+ ASSERT_SENTINEL(zh, ZBH); >+ BUG_ON(zh->size == 0 || zh->size > zbud_max_buddy_size()); >+ to_va = kmap_atomic(page, KM_USER0); >+ size = zh->size; >+ from_va = zbud_data(zh, size); >+ ret = lzo1x_decompress_safe(from_va, size, to_va, &out_len); >+ BUG_ON(ret != LZO_E_OK); >+ BUG_ON(out_len != PAGE_SIZE); >+ kunmap_atomic(to_va, KM_USER0); >+out: >+ spin_unlock(&zbpg->lock); >+ return ret; >+} >+ >+/* >+ * The following routines handle shrinking of ephemeral pages by evicting >+ * pages "least valuable" first. >+ */ >+ >+static unsigned long zcache_evicted_raw_pages; >+static unsigned long zcache_evicted_buddied_pages; >+static unsigned long zcache_evicted_unbuddied_pages; >+ >+static struct tmem_pool *zcache_get_pool_by_id(uint32_t poolid); >+static void zcache_put_pool(struct tmem_pool *pool); >+ >+/* >+ * Flush and free all zbuds in a zbpg, then free the pageframe >+ */ >+static void zbud_evict_zbpg(struct zbud_page *zbpg) >+{ >+ struct zbud_hdr *zh; >+ int i, j; >+ uint32_t pool_id[ZBUD_MAX_BUDS], index[ZBUD_MAX_BUDS]; >+ struct tmem_oid oid[ZBUD_MAX_BUDS]; >+ struct tmem_pool *pool; >+ >+ ASSERT_SPINLOCK(&zbpg->lock); >+ BUG_ON(!list_empty(&zbpg->bud_list)); >+ for (i = 0, j = 0; i < ZBUD_MAX_BUDS; i++) { >+ zh = &zbpg->buddy[i]; >+ if (zh->size) { >+ pool_id[j] = zh->pool_id; >+ oid[j] = zh->oid; >+ index[j] = zh->index; >+ j++; >+ zbud_free(zh); >+ } >+ } >+ spin_unlock(&zbpg->lock); >+ for (i = 0; i < j; i++) { >+ pool = zcache_get_pool_by_id(pool_id[i]); >+ if (pool != NULL) { >+ tmem_flush_page(pool, &oid[i], index[i]); >+ zcache_put_pool(pool); >+ } >+ } >+ ASSERT_SENTINEL(zbpg, ZBPG); >+ spin_lock(&zbpg->lock); >+ zbud_free_raw_page(zbpg); >+} >+ >+/* >+ * Free nr pages. This code is funky because we want to hold the locks >+ * protecting various lists for as short a time as possible, and in some >+ * circumstances the list may change asynchronously when the list lock is >+ * not held. In some cases we also trylock not only to avoid waiting on a >+ * page in use by another cpu, but also to avoid potential deadlock due to >+ * lock inversion. >+ */ >+static void zbud_evict_pages(int nr) >+{ >+ struct zbud_page *zbpg; >+ int i; >+ >+ /* first try freeing any pages on unused list */ >+retry_unused_list: >+ spin_lock_bh(&zbpg_unused_list_spinlock); >+ if (!list_empty(&zbpg_unused_list)) { >+ /* can't walk list here, since it may change when unlocked */ >+ zbpg = list_first_entry(&zbpg_unused_list, >+ struct zbud_page, bud_list); >+ list_del_init(&zbpg->bud_list); >+ zcache_zbpg_unused_list_count--; >+ atomic_dec(&zcache_zbud_curr_raw_pages); >+ spin_unlock_bh(&zbpg_unused_list_spinlock); >+ zcache_free_page(zbpg); >+ zcache_evicted_raw_pages++; >+ if (--nr <= 0) >+ goto out; >+ goto retry_unused_list; >+ } >+ spin_unlock_bh(&zbpg_unused_list_spinlock); >+ >+ /* now try freeing unbuddied pages, starting with least space avail */ >+ for (i = 0; i < MAX_CHUNK; i++) { >+retry_unbud_list_i: >+ spin_lock_bh(&zbud_budlists_spinlock); >+ if (list_empty(&zbud_unbuddied[i].list)) { >+ spin_unlock_bh(&zbud_budlists_spinlock); >+ continue; >+ } >+ list_for_each_entry(zbpg, &zbud_unbuddied[i].list, bud_list) { >+ if (unlikely(!spin_trylock(&zbpg->lock))) >+ continue; >+ list_del_init(&zbpg->bud_list); >+ zbud_unbuddied[i].count--; >+ spin_unlock(&zbud_budlists_spinlock); >+ zcache_evicted_unbuddied_pages++; >+ /* want budlists unlocked when doing zbpg eviction */ >+ zbud_evict_zbpg(zbpg); >+ local_bh_enable(); >+ if (--nr <= 0) >+ goto out; >+ goto retry_unbud_list_i; >+ } >+ spin_unlock_bh(&zbud_budlists_spinlock); >+ } >+ >+ /* as a last resort, free buddied pages */ >+retry_bud_list: >+ spin_lock_bh(&zbud_budlists_spinlock); >+ if (list_empty(&zbud_buddied_list)) { >+ spin_unlock_bh(&zbud_budlists_spinlock); >+ goto out; >+ } >+ list_for_each_entry(zbpg, &zbud_buddied_list, bud_list) { >+ if (unlikely(!spin_trylock(&zbpg->lock))) >+ continue; >+ list_del_init(&zbpg->bud_list); >+ zcache_zbud_buddied_count--; >+ spin_unlock(&zbud_budlists_spinlock); >+ zcache_evicted_buddied_pages++; >+ /* want budlists unlocked when doing zbpg eviction */ >+ zbud_evict_zbpg(zbpg); >+ local_bh_enable(); >+ if (--nr <= 0) >+ goto out; >+ goto retry_bud_list; >+ } >+ spin_unlock_bh(&zbud_budlists_spinlock); >+out: >+ return; >+} >+ >+static void zbud_init(void) >+{ >+ int i; >+ >+ INIT_LIST_HEAD(&zbud_buddied_list); >+ zcache_zbud_buddied_count = 0; >+ for (i = 0; i < NCHUNKS; i++) { >+ INIT_LIST_HEAD(&zbud_unbuddied[i].list); >+ zbud_unbuddied[i].count = 0; >+ } >+} >+ >+#ifdef CONFIG_SYSFS >+/* >+ * These sysfs routines show a nice distribution of how many zbpg's are >+ * currently (and have ever been placed) in each unbuddied list. It's fun >+ * to watch but can probably go away before final merge. >+ */ >+static int zbud_show_unbuddied_list_counts(char *buf) >+{ >+ int i; >+ char *p = buf; >+ >+ for (i = 0; i < NCHUNKS - 1; i++) >+ p += sprintf(p, "%u ", zbud_unbuddied[i].count); >+ p += sprintf(p, "%d\n", zbud_unbuddied[i].count); >+ return p - buf; >+} >+ >+static int zbud_show_cumul_chunk_counts(char *buf) >+{ >+ unsigned long i, chunks = 0, total_chunks = 0, sum_total_chunks = 0; >+ unsigned long total_chunks_lte_21 = 0, total_chunks_lte_32 = 0; >+ unsigned long total_chunks_lte_42 = 0; >+ char *p = buf; >+ >+ for (i = 0; i < NCHUNKS; i++) { >+ p += sprintf(p, "%lu ", zbud_cumul_chunk_counts[i]); >+ chunks += zbud_cumul_chunk_counts[i]; >+ total_chunks += zbud_cumul_chunk_counts[i]; >+ sum_total_chunks += i * zbud_cumul_chunk_counts[i]; >+ if (i == 21) >+ total_chunks_lte_21 = total_chunks; >+ if (i == 32) >+ total_chunks_lte_32 = total_chunks; >+ if (i == 42) >+ total_chunks_lte_42 = total_chunks; >+ } >+ p += sprintf(p, "<=21:%lu <=32:%lu <=42:%lu, mean:%lu\n", >+ total_chunks_lte_21, total_chunks_lte_32, total_chunks_lte_42, >+ chunks == 0 ? 0 : sum_total_chunks / chunks); >+ return p - buf; >+} >+#endif >+ >+/********** >+ * This "zv" PAM implementation combines the TLSF-based xvMalloc >+ * with lzo1x compression to maximize the amount of data that can >+ * be packed into a physical page. >+ * >+ * Zv represents a PAM page with the index and object (plus a "size" value >+ * necessary for decompression) immediately preceding the compressed data. >+ */ >+ >+#define ZVH_SENTINEL 0x43214321 >+ >+struct zv_hdr { >+ uint32_t pool_id; >+ struct tmem_oid oid; >+ uint32_t index; >+ DECL_SENTINEL >+}; >+ >+static const int zv_max_page_size = (PAGE_SIZE / 8) * 7; >+ >+static struct zv_hdr *zv_create(struct xv_pool *xvpool, uint32_t pool_id, >+ struct tmem_oid *oid, uint32_t index, >+ void *cdata, unsigned clen) >+{ >+ struct page *page; >+ struct zv_hdr *zv = NULL; >+ uint32_t offset; >+ int ret; >+ >+ BUG_ON(!irqs_disabled()); >+ ret = xv_malloc(xvpool, clen + sizeof(struct zv_hdr), >+ &page, &offset, ZCACHE_GFP_MASK); >+ if (unlikely(ret)) >+ goto out; >+ zv = kmap_atomic(page, KM_USER0) + offset; >+ zv->index = index; >+ zv->oid = *oid; >+ zv->pool_id = pool_id; >+ SET_SENTINEL(zv, ZVH); >+ memcpy((char *)zv + sizeof(struct zv_hdr), cdata, clen); >+ kunmap_atomic(zv, KM_USER0); >+out: >+ return zv; >+} >+ >+static void zv_free(struct xv_pool *xvpool, struct zv_hdr *zv) >+{ >+ unsigned long flags; >+ struct page *page; >+ uint32_t offset; >+ uint16_t size; >+ >+ ASSERT_SENTINEL(zv, ZVH); >+ size = xv_get_object_size(zv) - sizeof(*zv); >+ BUG_ON(size == 0 || size > zv_max_page_size); >+ INVERT_SENTINEL(zv, ZVH); >+ page = virt_to_page(zv); >+ offset = (unsigned long)zv & ~PAGE_MASK; >+ local_irq_save(flags); >+ xv_free(xvpool, page, offset); >+ local_irq_restore(flags); >+} >+ >+static void zv_decompress(struct page *page, struct zv_hdr *zv) >+{ >+ size_t clen = PAGE_SIZE; >+ char *to_va; >+ unsigned size; >+ int ret; >+ >+ ASSERT_SENTINEL(zv, ZVH); >+ size = xv_get_object_size(zv) - sizeof(*zv); >+ BUG_ON(size == 0 || size > zv_max_page_size); >+ to_va = kmap_atomic(page, KM_USER0); >+ ret = lzo1x_decompress_safe((char *)zv + sizeof(*zv), >+ size, to_va, &clen); >+ kunmap_atomic(to_va, KM_USER0); >+ BUG_ON(ret != LZO_E_OK); >+ BUG_ON(clen != PAGE_SIZE); >+} >+ >+/* >+ * zcache core code starts here >+ */ >+ >+/* useful stats not collected by cleancache or frontswap */ >+static unsigned long zcache_flush_total; >+static unsigned long zcache_flush_found; >+static unsigned long zcache_flobj_total; >+static unsigned long zcache_flobj_found; >+static unsigned long zcache_failed_eph_puts; >+static unsigned long zcache_failed_pers_puts; >+ >+#define MAX_POOLS_PER_CLIENT 16 >+ >+static struct { >+ struct tmem_pool *tmem_pools[MAX_POOLS_PER_CLIENT]; >+ struct xv_pool *xvpool; >+} zcache_client; >+ >+/* >+ * Tmem operations assume the poolid implies the invoking client. >+ * Zcache only has one client (the kernel itself), so translate >+ * the poolid into the tmem_pool allocated for it. A KVM version >+ * of zcache would have one client per guest and each client might >+ * have a poolid==N. >+ */ >+static struct tmem_pool *zcache_get_pool_by_id(uint32_t poolid) >+{ >+ struct tmem_pool *pool = NULL; >+ >+ if (poolid >= 0) { >+ pool = zcache_client.tmem_pools[poolid]; >+ if (pool != NULL) >+ atomic_inc(&pool->refcount); >+ } >+ return pool; >+} >+ >+static void zcache_put_pool(struct tmem_pool *pool) >+{ >+ if (pool != NULL) >+ atomic_dec(&pool->refcount); >+} >+ >+/* counters for debugging */ >+static unsigned long zcache_failed_get_free_pages; >+static unsigned long zcache_failed_alloc; >+static unsigned long zcache_put_to_flush; >+static unsigned long zcache_aborted_preload; >+static unsigned long zcache_aborted_shrink; >+ >+/* >+ * Ensure that memory allocation requests in zcache don't result >+ * in direct reclaim requests via the shrinker, which would cause >+ * an infinite loop. Maybe a GFP flag would be better? >+ */ >+static DEFINE_SPINLOCK(zcache_direct_reclaim_lock); >+ >+/* >+ * for now, used named slabs so can easily track usage; later can >+ * either just use kmalloc, or perhaps add a slab-like allocator >+ * to more carefully manage total memory utilization >+ */ >+static struct kmem_cache *zcache_objnode_cache; >+static struct kmem_cache *zcache_obj_cache; >+static atomic_t zcache_curr_obj_count = ATOMIC_INIT(0); >+static unsigned long zcache_curr_obj_count_max; >+static atomic_t zcache_curr_objnode_count = ATOMIC_INIT(0); >+static unsigned long zcache_curr_objnode_count_max; >+ >+/* >+ * to avoid memory allocation recursion (e.g. due to direct reclaim), we >+ * preload all necessary data structures so the hostops callbacks never >+ * actually do a malloc >+ */ >+struct zcache_preload { >+ void *page; >+ struct tmem_obj *obj; >+ int nr; >+ struct tmem_objnode *objnodes[OBJNODE_TREE_MAX_PATH]; >+}; >+static DEFINE_PER_CPU(struct zcache_preload, zcache_preloads) = { 0, }; >+ >+static int zcache_do_preload(struct tmem_pool *pool) >+{ >+ struct zcache_preload *kp; >+ struct tmem_objnode *objnode; >+ struct tmem_obj *obj; >+ void *page; >+ int ret = -ENOMEM; >+ >+ if (unlikely(zcache_objnode_cache == NULL)) >+ goto out; >+ if (unlikely(zcache_obj_cache == NULL)) >+ goto out; >+ if (!spin_trylock(&zcache_direct_reclaim_lock)) { >+ zcache_aborted_preload++; >+ goto out; >+ } >+ preempt_disable(); >+ kp = &__get_cpu_var(zcache_preloads); >+ while (kp->nr < ARRAY_SIZE(kp->objnodes)) { >+ preempt_enable_no_resched(); >+ objnode = kmem_cache_alloc(zcache_objnode_cache, >+ ZCACHE_GFP_MASK); >+ if (unlikely(objnode == NULL)) { >+ zcache_failed_alloc++; >+ goto unlock_out; >+ } >+ preempt_disable(); >+ kp = &__get_cpu_var(zcache_preloads); >+ if (kp->nr < ARRAY_SIZE(kp->objnodes)) >+ kp->objnodes[kp->nr++] = objnode; >+ else >+ kmem_cache_free(zcache_objnode_cache, objnode); >+ } >+ preempt_enable_no_resched(); >+ obj = kmem_cache_alloc(zcache_obj_cache, ZCACHE_GFP_MASK); >+ if (unlikely(obj == NULL)) { >+ zcache_failed_alloc++; >+ goto unlock_out; >+ } >+ page = (void *)__get_free_page(ZCACHE_GFP_MASK); >+ if (unlikely(page == NULL)) { >+ zcache_failed_get_free_pages++; >+ kmem_cache_free(zcache_obj_cache, obj); >+ goto unlock_out; >+ } >+ preempt_disable(); >+ kp = &__get_cpu_var(zcache_preloads); >+ if (kp->obj == NULL) >+ kp->obj = obj; >+ else >+ kmem_cache_free(zcache_obj_cache, obj); >+ if (kp->page == NULL) >+ kp->page = page; >+ else >+ free_page((unsigned long)page); >+ ret = 0; >+unlock_out: >+ spin_unlock(&zcache_direct_reclaim_lock); >+out: >+ return ret; >+} >+ >+static void *zcache_get_free_page(void) >+{ >+ struct zcache_preload *kp; >+ void *page; >+ >+ kp = &__get_cpu_var(zcache_preloads); >+ page = kp->page; >+ BUG_ON(page == NULL); >+ kp->page = NULL; >+ return page; >+} >+ >+static void zcache_free_page(void *p) >+{ >+ free_page((unsigned long)p); >+} >+ >+/* >+ * zcache implementation for tmem host ops >+ */ >+ >+static struct tmem_objnode *zcache_objnode_alloc(struct tmem_pool *pool) >+{ >+ struct tmem_objnode *objnode = NULL; >+ unsigned long count; >+ struct zcache_preload *kp; >+ >+ kp = &__get_cpu_var(zcache_preloads); >+ if (kp->nr <= 0) >+ goto out; >+ objnode = kp->objnodes[kp->nr - 1]; >+ BUG_ON(objnode == NULL); >+ kp->objnodes[kp->nr - 1] = NULL; >+ kp->nr--; >+ count = atomic_inc_return(&zcache_curr_objnode_count); >+ if (count > zcache_curr_objnode_count_max) >+ zcache_curr_objnode_count_max = count; >+out: >+ return objnode; >+} >+ >+static void zcache_objnode_free(struct tmem_objnode *objnode, >+ struct tmem_pool *pool) >+{ >+ atomic_dec(&zcache_curr_objnode_count); >+ BUG_ON(atomic_read(&zcache_curr_objnode_count) < 0); >+ kmem_cache_free(zcache_objnode_cache, objnode); >+} >+ >+static struct tmem_obj *zcache_obj_alloc(struct tmem_pool *pool) >+{ >+ struct tmem_obj *obj = NULL; >+ unsigned long count; >+ struct zcache_preload *kp; >+ >+ kp = &__get_cpu_var(zcache_preloads); >+ obj = kp->obj; >+ BUG_ON(obj == NULL); >+ kp->obj = NULL; >+ count = atomic_inc_return(&zcache_curr_obj_count); >+ if (count > zcache_curr_obj_count_max) >+ zcache_curr_obj_count_max = count; >+ return obj; >+} >+ >+static void zcache_obj_free(struct tmem_obj *obj, struct tmem_pool *pool) >+{ >+ atomic_dec(&zcache_curr_obj_count); >+ BUG_ON(atomic_read(&zcache_curr_obj_count) < 0); >+ kmem_cache_free(zcache_obj_cache, obj); >+} >+ >+static struct tmem_hostops zcache_hostops = { >+ .obj_alloc = zcache_obj_alloc, >+ .obj_free = zcache_obj_free, >+ .objnode_alloc = zcache_objnode_alloc, >+ .objnode_free = zcache_objnode_free, >+}; >+ >+/* >+ * zcache implementations for PAM page descriptor ops >+ */ >+ >+static atomic_t zcache_curr_eph_pampd_count = ATOMIC_INIT(0); >+static unsigned long zcache_curr_eph_pampd_count_max; >+static atomic_t zcache_curr_pers_pampd_count = ATOMIC_INIT(0); >+static unsigned long zcache_curr_pers_pampd_count_max; >+ >+/* forward reference */ >+static int zcache_compress(struct page *from, void **out_va, size_t *out_len); >+ >+static void *zcache_pampd_create(struct tmem_pool *pool, struct tmem_oid *oid, >+ uint32_t index, struct page *page) >+{ >+ void *pampd = NULL, *cdata; >+ size_t clen; >+ int ret; >+ bool ephemeral = is_ephemeral(pool); >+ unsigned long count; >+ >+ if (ephemeral) { >+ ret = zcache_compress(page, &cdata, &clen); >+ if (ret == 0) >+ >+ goto out; >+ if (clen == 0 || clen > zbud_max_buddy_size()) { >+ zcache_compress_poor++; >+ goto out; >+ } >+ pampd = (void *)zbud_create(pool->pool_id, oid, index, >+ page, cdata, clen); >+ if (pampd != NULL) { >+ count = atomic_inc_return(&zcache_curr_eph_pampd_count); >+ if (count > zcache_curr_eph_pampd_count_max) >+ zcache_curr_eph_pampd_count_max = count; >+ } >+ } else { >+ /* >+ * FIXME: This is all the "policy" there is for now. >+ * 3/4 totpages should allow ~37% of RAM to be filled with >+ * compressed frontswap pages >+ */ >+ if (atomic_read(&zcache_curr_pers_pampd_count) > >+ 3 * totalram_pages / 4) >+ goto out; >+ ret = zcache_compress(page, &cdata, &clen); >+ if (ret == 0) >+ goto out; >+ if (clen > zv_max_page_size) { >+ zcache_compress_poor++; >+ goto out; >+ } >+ pampd = (void *)zv_create(zcache_client.xvpool, pool->pool_id, >+ oid, index, cdata, clen); >+ if (pampd == NULL) >+ goto out; >+ count = atomic_inc_return(&zcache_curr_pers_pampd_count); >+ if (count > zcache_curr_pers_pampd_count_max) >+ zcache_curr_pers_pampd_count_max = count; >+ } >+out: >+ return pampd; >+} >+ >+/* >+ * fill the pageframe corresponding to the struct page with the data >+ * from the passed pampd >+ */ >+static int zcache_pampd_get_data(struct page *page, void *pampd, >+ struct tmem_pool *pool) >+{ >+ int ret = 0; >+ >+ if (is_ephemeral(pool)) >+ ret = zbud_decompress(page, pampd); >+ else >+ zv_decompress(page, pampd); >+ return ret; >+} >+ >+/* >+ * free the pampd and remove it from any zcache lists >+ * pampd must no longer be pointed to from any tmem data structures! >+ */ >+static void zcache_pampd_free(void *pampd, struct tmem_pool *pool) >+{ >+ if (is_ephemeral(pool)) { >+ zbud_free_and_delist((struct zbud_hdr *)pampd); >+ atomic_dec(&zcache_curr_eph_pampd_count); >+ BUG_ON(atomic_read(&zcache_curr_eph_pampd_count) < 0); >+ } else { >+ zv_free(zcache_client.xvpool, (struct zv_hdr *)pampd); >+ atomic_dec(&zcache_curr_pers_pampd_count); >+ BUG_ON(atomic_read(&zcache_curr_pers_pampd_count) < 0); >+ } >+} >+ >+static struct tmem_pamops zcache_pamops = { >+ .create = zcache_pampd_create, >+ .get_data = zcache_pampd_get_data, >+ .free = zcache_pampd_free, >+}; >+ >+/* >+ * zcache compression/decompression and related per-cpu stuff >+ */ >+ >+#define LZO_WORKMEM_BYTES LZO1X_1_MEM_COMPRESS >+#define LZO_DSTMEM_PAGE_ORDER 1 >+static DEFINE_PER_CPU(unsigned char *, zcache_workmem); >+static DEFINE_PER_CPU(unsigned char *, zcache_dstmem); >+ >+static int zcache_compress(struct page *from, void **out_va, size_t *out_len) >+{ >+ int ret = 0; >+ unsigned char *dmem = __get_cpu_var(zcache_dstmem); >+ unsigned char *wmem = __get_cpu_var(zcache_workmem); >+ char *from_va; >+ >+ BUG_ON(!irqs_disabled()); >+ if (unlikely(dmem == NULL || wmem == NULL)) >+ goto out; /* no buffer, so can't compress */ >+ from_va = kmap_atomic(from, KM_USER0); >+ mb(); >+ ret = lzo1x_1_compress(from_va, PAGE_SIZE, dmem, out_len, wmem); >+ BUG_ON(ret != LZO_E_OK); >+ *out_va = dmem; >+ kunmap_atomic(from_va, KM_USER0); >+ ret = 1; >+out: >+ return ret; >+} >+ >+ >+static int zcache_cpu_notifier(struct notifier_block *nb, >+ unsigned long action, void *pcpu) >+{ >+ int cpu = (long)pcpu; >+ struct zcache_preload *kp; >+ >+ switch (action) { >+ case CPU_UP_PREPARE: >+ per_cpu(zcache_dstmem, cpu) = (void *)__get_free_pages( >+ GFP_KERNEL | __GFP_REPEAT, >+ LZO_DSTMEM_PAGE_ORDER), >+ per_cpu(zcache_workmem, cpu) = >+ kzalloc(LZO1X_MEM_COMPRESS, >+ GFP_KERNEL | __GFP_REPEAT); >+ break; >+ case CPU_DEAD: >+ case CPU_UP_CANCELED: >+ free_pages((unsigned long)per_cpu(zcache_dstmem, cpu), >+ LZO_DSTMEM_PAGE_ORDER); >+ per_cpu(zcache_dstmem, cpu) = NULL; >+ kfree(per_cpu(zcache_workmem, cpu)); >+ per_cpu(zcache_workmem, cpu) = NULL; >+ kp = &per_cpu(zcache_preloads, cpu); >+ while (kp->nr) { >+ kmem_cache_free(zcache_objnode_cache, >+ kp->objnodes[kp->nr - 1]); >+ kp->objnodes[kp->nr - 1] = NULL; >+ kp->nr--; >+ } >+ kmem_cache_free(zcache_obj_cache, kp->obj); >+ free_page((unsigned long)kp->page); >+ break; >+ default: >+ break; >+ } >+ return NOTIFY_OK; >+} >+ >+static struct notifier_block zcache_cpu_notifier_block = { >+ .notifier_call = zcache_cpu_notifier >+}; >+ >+#ifdef CONFIG_SYSFS >+#define ZCACHE_SYSFS_RO(_name) \ >+ static ssize_t zcache_##_name##_show(struct kobject *kobj, \ >+ struct kobj_attribute *attr, char *buf) \ >+ { \ >+ return sprintf(buf, "%lu\n", zcache_##_name); \ >+ } \ >+ static struct kobj_attribute zcache_##_name##_attr = { \ >+ .attr = { .name = __stringify(_name), .mode = 0444 }, \ >+ .show = zcache_##_name##_show, \ >+ } >+ >+#define ZCACHE_SYSFS_RO_ATOMIC(_name) \ >+ static ssize_t zcache_##_name##_show(struct kobject *kobj, \ >+ struct kobj_attribute *attr, char *buf) \ >+ { \ >+ return sprintf(buf, "%d\n", atomic_read(&zcache_##_name)); \ >+ } \ >+ static struct kobj_attribute zcache_##_name##_attr = { \ >+ .attr = { .name = __stringify(_name), .mode = 0444 }, \ >+ .show = zcache_##_name##_show, \ >+ } >+ >+#define ZCACHE_SYSFS_RO_CUSTOM(_name, _func) \ >+ static ssize_t zcache_##_name##_show(struct kobject *kobj, \ >+ struct kobj_attribute *attr, char *buf) \ >+ { \ >+ return _func(buf); \ >+ } \ >+ static struct kobj_attribute zcache_##_name##_attr = { \ >+ .attr = { .name = __stringify(_name), .mode = 0444 }, \ >+ .show = zcache_##_name##_show, \ >+ } >+ >+ZCACHE_SYSFS_RO(curr_obj_count_max); >+ZCACHE_SYSFS_RO(curr_objnode_count_max); >+ZCACHE_SYSFS_RO(flush_total); >+ZCACHE_SYSFS_RO(flush_found); >+ZCACHE_SYSFS_RO(flobj_total); >+ZCACHE_SYSFS_RO(flobj_found); >+ZCACHE_SYSFS_RO(failed_eph_puts); >+ZCACHE_SYSFS_RO(failed_pers_puts); >+ZCACHE_SYSFS_RO(zbud_curr_zbytes); >+ZCACHE_SYSFS_RO(zbud_cumul_zpages); >+ZCACHE_SYSFS_RO(zbud_cumul_zbytes); >+ZCACHE_SYSFS_RO(zbud_buddied_count); >+ZCACHE_SYSFS_RO(zbpg_unused_list_count); >+ZCACHE_SYSFS_RO(evicted_raw_pages); >+ZCACHE_SYSFS_RO(evicted_unbuddied_pages); >+ZCACHE_SYSFS_RO(evicted_buddied_pages); >+ZCACHE_SYSFS_RO(failed_get_free_pages); >+ZCACHE_SYSFS_RO(failed_alloc); >+ZCACHE_SYSFS_RO(put_to_flush); >+ZCACHE_SYSFS_RO(aborted_preload); >+ZCACHE_SYSFS_RO(aborted_shrink); >+ZCACHE_SYSFS_RO(compress_poor); >+ZCACHE_SYSFS_RO_ATOMIC(zbud_curr_raw_pages); >+ZCACHE_SYSFS_RO_ATOMIC(zbud_curr_zpages); >+ZCACHE_SYSFS_RO_ATOMIC(curr_obj_count); >+ZCACHE_SYSFS_RO_ATOMIC(curr_objnode_count); >+ZCACHE_SYSFS_RO_CUSTOM(zbud_unbuddied_list_counts, >+ zbud_show_unbuddied_list_counts); >+ZCACHE_SYSFS_RO_CUSTOM(zbud_cumul_chunk_counts, >+ zbud_show_cumul_chunk_counts); >+ >+static struct attribute *zcache_attrs[] = { >+ &zcache_curr_obj_count_attr.attr, >+ &zcache_curr_obj_count_max_attr.attr, >+ &zcache_curr_objnode_count_attr.attr, >+ &zcache_curr_objnode_count_max_attr.attr, >+ &zcache_flush_total_attr.attr, >+ &zcache_flobj_total_attr.attr, >+ &zcache_flush_found_attr.attr, >+ &zcache_flobj_found_attr.attr, >+ &zcache_failed_eph_puts_attr.attr, >+ &zcache_failed_pers_puts_attr.attr, >+ &zcache_compress_poor_attr.attr, >+ &zcache_zbud_curr_raw_pages_attr.attr, >+ &zcache_zbud_curr_zpages_attr.attr, >+ &zcache_zbud_curr_zbytes_attr.attr, >+ &zcache_zbud_cumul_zpages_attr.attr, >+ &zcache_zbud_cumul_zbytes_attr.attr, >+ &zcache_zbud_buddied_count_attr.attr, >+ &zcache_zbpg_unused_list_count_attr.attr, >+ &zcache_evicted_raw_pages_attr.attr, >+ &zcache_evicted_unbuddied_pages_attr.attr, >+ &zcache_evicted_buddied_pages_attr.attr, >+ &zcache_failed_get_free_pages_attr.attr, >+ &zcache_failed_alloc_attr.attr, >+ &zcache_put_to_flush_attr.attr, >+ &zcache_aborted_preload_attr.attr, >+ &zcache_aborted_shrink_attr.attr, >+ &zcache_zbud_unbuddied_list_counts_attr.attr, >+ &zcache_zbud_cumul_chunk_counts_attr.attr, >+ NULL, >+}; >+ >+static struct attribute_group zcache_attr_group = { >+ .attrs = zcache_attrs, >+ .name = "zcache", >+}; >+ >+#endif /* CONFIG_SYSFS */ >+/* >+ * When zcache is disabled ("frozen"), pools can be created and destroyed, >+ * but all puts (and thus all other operations that require memory allocation) >+ * must fail. If zcache is unfrozen, accepts puts, then frozen again, >+ * data consistency requires all puts while frozen to be converted into >+ * flushes. >+ */ >+static bool zcache_freeze; >+ >+/* >+ * zcache shrinker interface (only useful for ephemeral pages, so zbud only) >+ */ >+static int shrink_zcache_memory(struct shrinker *shrink, >+ struct shrink_control *sc) >+{ >+ int ret = -1; >+ int nr = sc->nr_to_scan; >+ gfp_t gfp_mask = sc->gfp_mask; >+ >+ if (nr >= 0) { >+ if (!(gfp_mask & __GFP_FS)) >+ /* does this case really need to be skipped? */ >+ goto out; >+ if (spin_trylock(&zcache_direct_reclaim_lock)) { >+ zbud_evict_pages(nr); >+ spin_unlock(&zcache_direct_reclaim_lock); >+ } else >+ zcache_aborted_shrink++; >+ } >+ ret = (int)atomic_read(&zcache_zbud_curr_raw_pages); >+out: >+ return ret; >+} >+ >+static struct shrinker zcache_shrinker = { >+ .shrink = shrink_zcache_memory, >+ .seeks = DEFAULT_SEEKS, >+}; >+ >+/* >+ * zcache shims between cleancache/frontswap ops and tmem >+ */ >+ >+static int zcache_put_page(int pool_id, struct tmem_oid *oidp, >+ uint32_t index, struct page *page) >+{ >+ struct tmem_pool *pool; >+ int ret = -1; >+ >+ BUG_ON(!irqs_disabled()); >+ pool = zcache_get_pool_by_id(pool_id); >+ if (unlikely(pool == NULL)) >+ goto out; >+ if (!zcache_freeze && zcache_do_preload(pool) == 0) { >+ /* preload does preempt_disable on success */ >+ ret = tmem_put(pool, oidp, index, page); >+ if (ret < 0) { >+ if (is_ephemeral(pool)) >+ zcache_failed_eph_puts++; >+ else >+ zcache_failed_pers_puts++; >+ } >+ zcache_put_pool(pool); >+ preempt_enable_no_resched(); >+ } else { >+ zcache_put_to_flush++; >+ if (atomic_read(&pool->obj_count) > 0) >+ /* the put fails whether the flush succeeds or not */ >+ (void)tmem_flush_page(pool, oidp, index); >+ zcache_put_pool(pool); >+ } >+out: >+ return ret; >+} >+ >+static int zcache_get_page(int pool_id, struct tmem_oid *oidp, >+ uint32_t index, struct page *page) >+{ >+ struct tmem_pool *pool; >+ int ret = -1; >+ unsigned long flags; >+ >+ local_irq_save(flags); >+ pool = zcache_get_pool_by_id(pool_id); >+ if (likely(pool != NULL)) { >+ if (atomic_read(&pool->obj_count) > 0) >+ ret = tmem_get(pool, oidp, index, page); >+ zcache_put_pool(pool); >+ } >+ local_irq_restore(flags); >+ return ret; >+} >+ >+static int zcache_flush_page(int pool_id, struct tmem_oid *oidp, uint32_t index) >+{ >+ struct tmem_pool *pool; >+ int ret = -1; >+ unsigned long flags; >+ >+ local_irq_save(flags); >+ zcache_flush_total++; >+ pool = zcache_get_pool_by_id(pool_id); >+ if (likely(pool != NULL)) { >+ if (atomic_read(&pool->obj_count) > 0) >+ ret = tmem_flush_page(pool, oidp, index); >+ zcache_put_pool(pool); >+ } >+ if (ret >= 0) >+ zcache_flush_found++; >+ local_irq_restore(flags); >+ return ret; >+} >+ >+static int zcache_flush_object(int pool_id, struct tmem_oid *oidp) >+{ >+ struct tmem_pool *pool; >+ int ret = -1; >+ unsigned long flags; >+ >+ local_irq_save(flags); >+ zcache_flobj_total++; >+ pool = zcache_get_pool_by_id(pool_id); >+ if (likely(pool != NULL)) { >+ if (atomic_read(&pool->obj_count) > 0) >+ ret = tmem_flush_object(pool, oidp); >+ zcache_put_pool(pool); >+ } >+ if (ret >= 0) >+ zcache_flobj_found++; >+ local_irq_restore(flags); >+ return ret; >+} >+ >+static int zcache_destroy_pool(int pool_id) >+{ >+ struct tmem_pool *pool = NULL; >+ int ret = -1; >+ >+ if (pool_id < 0) >+ goto out; >+ pool = zcache_client.tmem_pools[pool_id]; >+ if (pool == NULL) >+ goto out; >+ zcache_client.tmem_pools[pool_id] = NULL; >+ /* wait for pool activity on other cpus to quiesce */ >+ while (atomic_read(&pool->refcount) != 0) >+ ; >+ local_bh_disable(); >+ ret = tmem_destroy_pool(pool); >+ local_bh_enable(); >+ kfree(pool); >+ pr_info("zcache: destroyed pool id=%d\n", pool_id); >+out: >+ return ret; >+} >+ >+static int zcache_new_pool(uint32_t flags) >+{ >+ int poolid = -1; >+ struct tmem_pool *pool; >+ >+ pool = kmalloc(sizeof(struct tmem_pool), GFP_KERNEL); >+ if (pool == NULL) { >+ pr_info("zcache: pool creation failed: out of memory\n"); >+ goto out; >+ } >+ >+ for (poolid = 0; poolid < MAX_POOLS_PER_CLIENT; poolid++) >+ if (zcache_client.tmem_pools[poolid] == NULL) >+ break; >+ if (poolid >= MAX_POOLS_PER_CLIENT) { >+ pr_info("zcache: pool creation failed: max exceeded\n"); >+ kfree(pool); >+ poolid = -1; >+ goto out; >+ } >+ atomic_set(&pool->refcount, 0); >+ pool->client = &zcache_client; >+ pool->pool_id = poolid; >+ tmem_new_pool(pool, flags); >+ zcache_client.tmem_pools[poolid] = pool; >+ pr_info("zcache: created %s tmem pool, id=%d\n", >+ flags & TMEM_POOL_PERSIST ? "persistent" : "ephemeral", >+ poolid); >+out: >+ return poolid; >+} >+ >+/********** >+ * Two kernel functionalities currently can be layered on top of tmem. >+ * These are "cleancache" which is used as a second-chance cache for clean >+ * page cache pages; and "frontswap" which is used for swap pages >+ * to avoid writes to disk. A generic "shim" is provided here for each >+ * to translate in-kernel semantics to zcache semantics. >+ */ >+ >+#ifdef CONFIG_CLEANCACHE >+static void zcache_cleancache_put_page(int pool_id, >+ struct cleancache_filekey key, >+ pgoff_t index, struct page *page) >+{ >+ u32 ind = (u32) index; >+ struct tmem_oid oid = *(struct tmem_oid *)&key; >+ >+ if (likely(ind == index)) >+ (void)zcache_put_page(pool_id, &oid, index, page); >+} >+ >+static int zcache_cleancache_get_page(int pool_id, >+ struct cleancache_filekey key, >+ pgoff_t index, struct page *page) >+{ >+ u32 ind = (u32) index; >+ struct tmem_oid oid = *(struct tmem_oid *)&key; >+ int ret = -1; >+ >+ if (likely(ind == index)) >+ ret = zcache_get_page(pool_id, &oid, index, page); >+ return ret; >+} >+ >+static void zcache_cleancache_flush_page(int pool_id, >+ struct cleancache_filekey key, >+ pgoff_t index) >+{ >+ u32 ind = (u32) index; >+ struct tmem_oid oid = *(struct tmem_oid *)&key; >+ >+ if (likely(ind == index)) >+ (void)zcache_flush_page(pool_id, &oid, ind); >+} >+ >+static void zcache_cleancache_flush_inode(int pool_id, >+ struct cleancache_filekey key) >+{ >+ struct tmem_oid oid = *(struct tmem_oid *)&key; >+ >+ (void)zcache_flush_object(pool_id, &oid); >+} >+ >+static void zcache_cleancache_flush_fs(int pool_id) >+{ >+ if (pool_id >= 0) >+ (void)zcache_destroy_pool(pool_id); >+} >+ >+static int zcache_cleancache_init_fs(size_t pagesize) >+{ >+ BUG_ON(sizeof(struct cleancache_filekey) != >+ sizeof(struct tmem_oid)); >+ BUG_ON(pagesize != PAGE_SIZE); >+ return zcache_new_pool(0); >+} >+ >+static int zcache_cleancache_init_shared_fs(char *uuid, size_t pagesize) >+{ >+ /* shared pools are unsupported and map to private */ >+ BUG_ON(sizeof(struct cleancache_filekey) != >+ sizeof(struct tmem_oid)); >+ BUG_ON(pagesize != PAGE_SIZE); >+ return zcache_new_pool(0); >+} >+ >+static struct cleancache_ops zcache_cleancache_ops = { >+ .put_page = zcache_cleancache_put_page, >+ .get_page = zcache_cleancache_get_page, >+ .flush_page = zcache_cleancache_flush_page, >+ .flush_inode = zcache_cleancache_flush_inode, >+ .flush_fs = zcache_cleancache_flush_fs, >+ .init_shared_fs = zcache_cleancache_init_shared_fs, >+ .init_fs = zcache_cleancache_init_fs >+}; >+ >+struct cleancache_ops zcache_cleancache_register_ops(void) >+{ >+ struct cleancache_ops old_ops = >+ cleancache_register_ops(&zcache_cleancache_ops); >+ >+ return old_ops; >+} >+#endif >+ >+#ifdef CONFIG_FRONTSWAP >+/* a single tmem poolid is used for all frontswap "types" (swapfiles) */ >+static int zcache_frontswap_poolid = -1; >+ >+/* >+ * Swizzling increases objects per swaptype, increasing tmem concurrency >+ * for heavy swaploads. Later, larger nr_cpus -> larger SWIZ_BITS >+ */ >+#define SWIZ_BITS 4 >+#define SWIZ_MASK ((1 << SWIZ_BITS) - 1) >+#define _oswiz(_type, _ind) ((_type << SWIZ_BITS) | (_ind & SWIZ_MASK)) >+#define iswiz(_ind) (_ind >> SWIZ_BITS) >+ >+static inline struct tmem_oid oswiz(unsigned type, u32 ind) >+{ >+ struct tmem_oid oid = { .oid = { 0 } }; >+ oid.oid[0] = _oswiz(type, ind); >+ return oid; >+} >+ >+static int zcache_frontswap_put_page(unsigned type, pgoff_t offset, >+ struct page *page) >+{ >+ u64 ind64 = (u64)offset; >+ u32 ind = (u32)offset; >+ struct tmem_oid oid = oswiz(type, ind); >+ int ret = -1; >+ unsigned long flags; >+ >+ BUG_ON(!PageLocked(page)); >+ if (likely(ind64 == ind)) { >+ local_irq_save(flags); >+ ret = zcache_put_page(zcache_frontswap_poolid, &oid, >+ iswiz(ind), page); >+ local_irq_restore(flags); >+ } >+ return ret; >+} >+ >+/* returns 0 if the page was successfully gotten from frontswap, -1 if >+ * was not present (should never happen!) */ >+static int zcache_frontswap_get_page(unsigned type, pgoff_t offset, >+ struct page *page) >+{ >+ u64 ind64 = (u64)offset; >+ u32 ind = (u32)offset; >+ struct tmem_oid oid = oswiz(type, ind); >+ int ret = -1; >+ >+ BUG_ON(!PageLocked(page)); >+ if (likely(ind64 == ind)) >+ ret = zcache_get_page(zcache_frontswap_poolid, &oid, >+ iswiz(ind), page); >+ return ret; >+} >+ >+/* flush a single page from frontswap */ >+static void zcache_frontswap_flush_page(unsigned type, pgoff_t offset) >+{ >+ u64 ind64 = (u64)offset; >+ u32 ind = (u32)offset; >+ struct tmem_oid oid = oswiz(type, ind); >+ >+ if (likely(ind64 == ind)) >+ (void)zcache_flush_page(zcache_frontswap_poolid, &oid, >+ iswiz(ind)); >+} >+ >+/* flush all pages from the passed swaptype */ >+static void zcache_frontswap_flush_area(unsigned type) >+{ >+ struct tmem_oid oid; >+ int ind; >+ >+ for (ind = SWIZ_MASK; ind >= 0; ind--) { >+ oid = oswiz(type, ind); >+ (void)zcache_flush_object(zcache_frontswap_poolid, &oid); >+ } >+} >+ >+static void zcache_frontswap_init(unsigned ignored) >+{ >+ /* a single tmem poolid is used for all frontswap "types" (swapfiles) */ >+ if (zcache_frontswap_poolid < 0) >+ zcache_frontswap_poolid = zcache_new_pool(TMEM_POOL_PERSIST); >+} >+ >+static struct frontswap_ops zcache_frontswap_ops = { >+ .put_page = zcache_frontswap_put_page, >+ .get_page = zcache_frontswap_get_page, >+ .flush_page = zcache_frontswap_flush_page, >+ .flush_area = zcache_frontswap_flush_area, >+ .init = zcache_frontswap_init >+}; >+ >+struct frontswap_ops zcache_frontswap_register_ops(void) >+{ >+ struct frontswap_ops old_ops = >+ frontswap_register_ops(&zcache_frontswap_ops); >+ >+ return old_ops; >+} >+#endif >+ >+/* >+ * zcache initialization >+ * NOTE FOR NOW zcache MUST BE PROVIDED AS A KERNEL BOOT PARAMETER OR >+ * NOTHING HAPPENS! >+ */ >+ >+static int zcache_enabled; >+ >+static int __init enable_zcache(char *s) >+{ >+ zcache_enabled = 1; >+ return 1; >+} >+__setup("zcache", enable_zcache); >+ >+/* allow independent dynamic disabling of cleancache and frontswap */ >+ >+static int use_cleancache = 1; >+ >+static int __init no_cleancache(char *s) >+{ >+ use_cleancache = 0; >+ return 1; >+} >+ >+__setup("nocleancache", no_cleancache); >+ >+static int use_frontswap = 1; >+ >+static int __init no_frontswap(char *s) >+{ >+ use_frontswap = 0; >+ return 1; >+} >+ >+__setup("nofrontswap", no_frontswap); >+ >+static int __init zcache_init(void) >+{ >+#ifdef CONFIG_SYSFS >+ int ret = 0; >+ >+ ret = sysfs_create_group(mm_kobj, &zcache_attr_group); >+ if (ret) { >+ pr_err("zcache: can't create sysfs\n"); >+ goto out; >+ } >+#endif /* CONFIG_SYSFS */ >+#if defined(CONFIG_CLEANCACHE) || defined(CONFIG_FRONTSWAP) >+ if (zcache_enabled) { >+ unsigned int cpu; >+ >+ tmem_register_hostops(&zcache_hostops); >+ tmem_register_pamops(&zcache_pamops); >+ ret = register_cpu_notifier(&zcache_cpu_notifier_block); >+ if (ret) { >+ pr_err("zcache: can't register cpu notifier\n"); >+ goto out; >+ } >+ for_each_online_cpu(cpu) { >+ void *pcpu = (void *)(long)cpu; >+ zcache_cpu_notifier(&zcache_cpu_notifier_block, >+ CPU_UP_PREPARE, pcpu); >+ } >+ } >+ zcache_objnode_cache = kmem_cache_create("zcache_objnode", >+ sizeof(struct tmem_objnode), 0, 0, NULL); >+ zcache_obj_cache = kmem_cache_create("zcache_obj", >+ sizeof(struct tmem_obj), 0, 0, NULL); >+#endif >+#ifdef CONFIG_CLEANCACHE >+ if (zcache_enabled && use_cleancache) { >+ struct cleancache_ops old_ops; >+ >+ zbud_init(); >+ register_shrinker(&zcache_shrinker); >+ old_ops = zcache_cleancache_register_ops(); >+ pr_info("zcache: cleancache enabled using kernel " >+ "transcendent memory and compression buddies\n"); >+ if (old_ops.init_fs != NULL) >+ pr_warning("zcache: cleancache_ops overridden"); >+ } >+#endif >+#ifdef CONFIG_FRONTSWAP >+ if (zcache_enabled && use_frontswap) { >+ struct frontswap_ops old_ops; >+ >+ zcache_client.xvpool = xv_create_pool(); >+ if (zcache_client.xvpool == NULL) { >+ pr_err("zcache: can't create xvpool\n"); >+ goto out; >+ } >+ old_ops = zcache_frontswap_register_ops(); >+ pr_info("zcache: frontswap enabled using kernel " >+ "transcendent memory and xvmalloc\n"); >+ if (old_ops.init != NULL) >+ pr_warning("ktmem: frontswap_ops overridden"); >+ } >+#endif >+out: >+ return ret; >+} >+ >+module_init(zcache_init)
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