Summary: | linux-4.{2,3}: multicore scheduling not working when NO_HZ_FULL is set | ||
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Product: | Gentoo Linux | Reporter: | Martin Wohlert <martin> |
Component: | [OLD] Core system | Assignee: | Gentoo Kernel Bug Wranglers and Kernel Maintainers <kernel> |
Status: | RESOLVED UPSTREAM | ||
Severity: | major | CC: | aaaaaa111111, leho |
Priority: | Normal | ||
Version: | unspecified | ||
Hardware: | All | ||
OS: | Linux | ||
URL: | https://bugzilla.kernel.org/show_bug.cgi?id=101021 | ||
Whiteboard: | |||
Package list: | Runtime testing required: | --- |
Description
Martin Wohlert
2015-09-02 07:16:01 UTC
Same here. 1. emerge gentoo-sources-4.2.0 2. get config from 4.1.6 (zcat /proc/config.gz >.config) 3. book new kernel - only one core working from four (in top there are four cores) For me vanilla-sources-4.2.0 also not working. Again one core from four. Try CONFIG_NO_HZ_IDLE=y # CONFIG_NO_HZ_FULL is not set @josef.95 Thanks for your hint! My machines are fully functional again now. Not fixed, judging by bug #559382. *** Bug 559556 has been marked as a duplicate of this bug. *** I get same issue. 4.2.1 has same issue (In reply to Alexey Shvetsov from comment #8) > 4.2.1 has same issue Did you try this? CONFIG_NO_HZ_COMMON=y CONFIG_NO_HZ_IDLE=y # CONFIG_NO_HZ_FULL is not set CONFIG_NO_HZ=y 4.2.2 has same problem. P.S. for Mike Pagano "when NO_HZ_FULL is set" (In reply to Artemii from comment #10) > 4.2.2 has same problem. > > P.S. for Mike Pagano "when NO_HZ_FULL is set" Can you do me a favor please and try the above with git-sources ? The latest version if you don't mind. (In reply to Mike Pagano from comment #11) > Can you do me a favor please and try the above with git-sources ? > > The latest version if you don't mind. 4.3-rc3 still has same problem. (In reply to Artemii from comment #12) > (In reply to Mike Pagano from comment #11) > > Can you do me a favor please and try the above with git-sources ? > > > > The latest version if you don't mind. > > 4.3-rc3 still has same problem. What do you have for NO_HZ_FULL ? (In reply to Mike Pagano from comment #13) > (In reply to Artemii from comment #12) > > > > 4.3-rc3 still has same problem. > > What do you have for NO_HZ_FULL ? CONFIG_NO_HZ_FULL=y CONFIG_NO_HZ_FULL_ALL=y # CONFIG_NO_HZ_FULL_SYSIDLE is not set cpuinfo tell about eight cores AMD FX(tm)-8120 (In reply to Artemii from comment #14) > (In reply to Mike Pagano from comment #13) > > (In reply to Artemii from comment #12) > > > > > > 4.3-rc3 still has same problem. > > > > What do you have for NO_HZ_FULL ? > > CONFIG_NO_HZ_FULL=y > CONFIG_NO_HZ_FULL_ALL=y > # CONFIG_NO_HZ_FULL_SYSIDLE is not set > > cpuinfo tell about eight cores AMD FX(tm)-8120 try this CONFIG_NO_HZ_COMMON=y CONFIG_NO_HZ_IDLE=y # CONFIG_NO_HZ_FULL is not set CONFIG_NO_HZ=y (In reply to Mike Pagano from comment #15) > try this > > CONFIG_NO_HZ_COMMON=y > CONFIG_NO_HZ_IDLE=y > # CONFIG_NO_HZ_FULL is not set > CONFIG_NO_HZ=y In this case multicore scheduling works fine. still seeing this with 4.2.3 kernel 4.3-rc6 also affected. Tested on x86 and armv7l Another fun error. If SERVER PREEMPTION set also all tasks will go to core0 This is probably the relevant LKML thread response https://lkml.org/lkml/2015/7/15/762 |