I have a laptop with Core i5 and x2apic (as per /proc/cpuinfo). Enabling CONFIG_X86_X2APIC in vanilla 3.9.3 causes these symptoms: * sluggish kernel boot * a couple times during boot: "BUG: unable to handle kernel", Oops, kernel panic, NULL pointer dereference, "CPU.*Stuck" * ~twice slower HDD I/O * very high CPU temperature despite no CPU load (reported by physical fan speed and /usr/bin/acpi) * only 1 CPU available in the booted system (should be 2 + 2/HT) * "ACPI Warning.*SystemIO conflicts with Region \GPIO 1" * driver iwlwifi cannot load firmware (could be due to the prolonged boot, but it wasn't *that* long...) * "i8042: Can't write CTR while closing KBD port", "i8042: Can't reactivate KBD port" * when running, every now and then the kernel pauses for a fraction of a second It has nothing to do with power mgmt - disabling everything under "Power management and ACPI options" (except for ACPI_BUTTON and ACPI_VIDEO which are enforced) doesn't help. Reproducible: Always
Created attachment 348748 [details] .config (with X2APIC) when I remove X2APIC from this, the problems are gone
Created attachment 348750 [details] dmesg (with X2APIC)
Created attachment 348752 [details] lspci -vvv
Created attachment 348758 [details] emerge --info hwids
Created attachment 348760 [details] /proc/cpuinfo (without X2APIC)
That's quite unfortunate, will do some more research on this; a quick search yields nothing of interest upstream, will look at other bug sites and commit history later.
Have you run any earlier kernel versions with this setitng enabled?
(In reply to comment #7) > Have you run any earlier kernel versions with this setitng enabled? No. Shall I try? I think it deps on EXPERIMENTAL or something in 3.8.
(In reply to comment #8) > (In reply to comment #7) > > Have you run any earlier kernel versions with this setitng enabled? > > No. Shall I try? I think it deps on EXPERIMENTAL or something in 3.8. You can if you like. It would be great if it worked in an earlier version, then we could pinpoint the patch that causes the error.
Tried 3.8.12-hardened now. It works just fine with X2APIC. Here's the diff from my regular 3.8.12-hardened config. # diff config-3.8.12-hardened.old config-3.8.12-hardened|grep '^[><][^#]*$' > CONFIG_HAVE_INTEL_TXT=y > CONFIG_EXPERIMENTAL=y > CONFIG_X86_X2APIC=y > CONFIG_NET_VENDOR_I825XX=y > CONFIG_NET_VENDOR_SEEQ=y > CONFIG_NET_VENDOR_SILAN=y > CONFIG_IRQ_REMAP=y What hits me is the INTEL_TXT which somehow got in automagically. I do have that in the laptop too, although I make no use of it, and I had it off in the 3.9.3 config. Will try 3.9.3 with +X2APIC+TXT and 3.8.12 with +X2APIC-TXT soon.
Sorry, CONFIG_HAVE_INTEL_TXT=y has always been there even in 3.9.3 - it's an automatic option. I mistook it for CONFIG_INTEL_TXT which is actually selectable and has never been on in any of the configs. I ended up trying 3.9.3 with CONFIG_INTEL_TXT=y (and the other one =y too) - no change.
Tried vanilla-3.8.13 and it runs without a flaw. Here, "config-3.8.12-hardened.old" is the same one as in comment 10 (my regular, non-X2APIC hardened 3.8). $ diff config-3.8.12-hardened.old config-3.8.13|egrep -v '(CONFIG_GRKERNSEC|CONFIG_PAX)'|grep '^[><] CONFIG' > CONFIG_HAVE_INTEL_TXT=y > CONFIG_EXPERIMENTAL=y > CONFIG_X86_X2APIC=y < CONFIG_X86_ALIGNMENT_16=y > CONFIG_IRQ_REMAP=y > CONFIG_DEBUG_RODATA=y > CONFIG_DEBUG_SET_MODULE_RONX=y > CONFIG_DEBUG_STRICT_USER_COPY_CHECKS=y < CONFIG_TASK_SIZE_MAX_SHIFT=42
(Ad. previous comment: so that's a X2APIC-enabled 3.8.13 that runs fine here. The IRQ_REMAP option is under Drivers->IOMMU and is a dependency of X2APIC). This is the diff between an early X2APIC-enabled 3.9.3 failing config that I tested and the current 3.8.13 operational X2APIC-enabled one. # diff .config /tmp/config-3.9.3-fail1 |grep '^[><] CONFIG' < CONFIG_HAVE_IRQ_WORK=y < CONFIG_EXPERIMENTAL=y > CONFIG_RCU_STALL_COMMON=y > CONFIG_ARCH_USE_BUILTIN_BSWAP=y > CONFIG_HAVE_KPROBES_ON_FTRACE=y < CONFIG_GENERIC_SIGALTSTACK=y > CONFIG_OLD_SIGSUSPEND3=y > CONFIG_COMPAT_OLD_SIGACTION=y > CONFIG_PADATA=y < CONFIG_NR_CPUS=4 > CONFIG_MAXSMP=y > CONFIG_NR_CPUS=4096 > CONFIG_ACPI_PROCESSOR_AGGREGATOR=y > CONFIG_NETWORK_PHY_TIMESTAMPING=y > CONFIG_SCSI_TGT=m > CONFIG_TTY=y > CONFIG_PPS=y > CONFIG_PTP_1588_CLOCK=y > CONFIG_GPIO_DEVRES=y < CONFIG_STEP_WISE=y > CONFIG_THERMAL_GOV_STEP_WISE=y > CONFIG_DRM_TTM=m > CONFIG_DRM_GMA500=m > CONFIG_HDMI=y > CONFIG_MMC_CLKGATE=y > CONFIG_HAVE_DYNAMIC_FTRACE_WITH_REGS=y > CONFIG_CRYPTO_AEAD=y > CONFIG_CRYPTO_PCRYPT=y < CONFIG_PERCPU_RWSEM=y > CONFIG_CPUMASK_OFFSTACK=y
Finally some good news! I got 3.9.3 working. # diff config-3.9.3.old config-3.9.3 313,314c313,314 < CONFIG_MAXSMP=y < CONFIG_NR_CPUS=4096 --- > # CONFIG_MAXSMP is not set > CONFIG_NR_CPUS=4 2744d2743 < CONFIG_CPUMASK_OFFSTACK=y This happened when I turned off MAXSMP. MAXSMP is available in vanilla 3.8.13 too, but I didn't enable it during the tests here. Conclusion (for vanilla 3.9.3, at least): either MAXSMP, or X86_X2APIC, but not both. I didn't test with neither, but I expect a no-problem there. Please let me know if you're going to work on a patch; else I think this should reach upstream. If you're not going to report it, let me know.
Tested -MAXSMP, +X2APIC, +ACPI, +Intel P state driver - no problem.
(In reply to comment #14) > Please let me know if you're going to work on a patch; else I think this should reach upstream. No idea what's specifically going wrong here; so, since you know the problem best feel free to report this upstream at http://bugzilla.kernel.org.
Also, you will probably need to enable debugging info (CONFIG_EXPERT=y and CONFIG_DEBUG_KERNEL=y if I recall correctly, maybe you can enable CONFIG_DEBUG_INFO=y as well) to have a readable stack trace in the dmesg when you are reporting; with its current version it is not possible to deduce where exactly the issue occured.
