linux/arch
Peter Zijlstra 4407204c5c perf, x86: Detect broken BIOSes that corrupt the PMU
Some BIOSes use PMU resources, which can cause various bugs:

 - Non-working or erratic PMU based statistics - the PMU can end up
   counting the wrong thing, resulting in misleading statistics

 - Profiling can stop working or it can profile the wrong thing

 - A non-working or erratic NMI watchdog that cannot be relied on

 - The kernel may disturb whatever thing the BIOS tries to use the
   PMU for - possibly causing hardware malfunction in extreme cases.

 - ... and other forms of potential misbehavior

Various forms of such misbehavior has been observed in practice - there are
BIOSes that just corrupt the PMU state, consequences be damned.

The PMU is a CPU resource that is handled by the kernel and the BIOS
stealing+corrupting it is not acceptable nor robust, so we detect it,
warn about it and further refuse to touch the PMU ourselves.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Jason Wessel <jason.wessel@windriver.com>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-12-16 11:36:42 +01:00
..
alpha perf, arch: Cleanup perf-pmu init vs lockup-detector 2010-11-26 15:14:56 +01:00
arm Merge branch 'perf/urgent' into perf/core 2010-12-16 11:22:27 +01:00
avr32 Merge branch 'kconfig' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild-2.6 2010-10-28 16:16:39 -07:00
blackfin BKL: remove extraneous #include <smp_lock.h> 2010-11-17 08:59:32 -08:00
cris Merge branch 'kconfig' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild-2.6 2010-10-28 16:16:39 -07:00
frv BKL: remove extraneous #include <smp_lock.h> 2010-11-17 08:59:32 -08:00
h8300 BKL: remove extraneous #include <smp_lock.h> 2010-11-17 08:59:32 -08:00
ia64 SCSI host lock push-down 2010-11-16 13:33:23 -08:00
m32r Merge branch 'kconfig' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild-2.6 2010-10-28 16:16:39 -07:00
m68k BKL: remove extraneous #include <smp_lock.h> 2010-11-17 08:59:32 -08:00
m68knommu BKL: remove extraneous #include <smp_lock.h> 2010-11-17 08:59:32 -08:00
microblaze Merge branch 'kconfig' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild-2.6 2010-10-28 16:16:39 -07:00
mips perf, arch: Cleanup perf-pmu init vs lockup-detector 2010-11-26 15:14:56 +01:00
mn10300 MN10300: Fix interrupt mask alteration function call name in gdbstub 2010-12-07 11:29:14 -08:00
parisc parisc: convert the rest of the irq handlers to simple/percpu 2010-12-04 11:15:19 -05:00
powerpc Merge commit 'v2.6.37-rc5' into perf/core 2010-12-07 07:49:51 +01:00
s390 [S390] nohz/s390: fix arch_needs_cpu() return value on offline cpus 2010-12-01 10:08:17 +01:00
score Merge branch 'kconfig' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild-2.6 2010-10-28 16:16:39 -07:00
sh Merge commit 'v2.6.37-rc5' into perf/core 2010-12-07 07:49:51 +01:00
sparc perf, sparc: Fix CONFIG_PERF_EVENTS=y build error 2010-12-10 00:29:24 +01:00
tile Merge git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile 2010-11-25 07:42:32 +09:00
um uml: disable winch irq before freeing handler data 2010-11-25 06:50:39 +09:00
x86 perf, x86: Detect broken BIOSes that corrupt the PMU 2010-12-16 11:36:42 +01:00
xtensa Merge branch 'kconfig' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild-2.6 2010-10-28 16:16:39 -07:00
.gitignore
Kconfig jump label: Add work around to i386 gcc asm goto bug 2010-10-29 14:45:29 -04:00