linux/arch
Don Zickus 2e556b5b32 perf, x86: Fix accidentally ack'ing a second event on intel perf counter
During testing of a patch to stop having the perf subsytem
swallow nmis, it was uncovered that Nehalem boxes were randomly
getting unknown nmis when using the perf tool.

Moving the ack'ing of the PMI closer to when we get the status
allows the hardware to properly re-set the PMU bit signaling
another PMI was triggered during the processing of the first
PMI.  This allows the new logic for dealing with the
shortcomings of multiple PMIs to handle the extra NMI by
'eat'ing it later.

Now one can wonder why are we getting a second PMI when we
disable all the PMUs in the begining of the NMI handler to
prevent such a case, for that I do not know.  But I know the fix
below helps deal with this quirk.

Tested on multiple Nehalems where the problem was occuring.
With the patch, the code now loops a second time to handle the
second PMI (whereas before it was not).

Signed-off-by: Don Zickus <dzickus@redhat.com>
Cc: peterz@infradead.org
Cc: robert.richter@amd.com
Cc: gorcunov@gmail.com
Cc: fweisbec@gmail.com
Cc: ying.huang@intel.com
Cc: ming.m.lin@intel.com
Cc: eranian@google.com
LKML-Reference: <1283454469-1909-2-git-send-email-dzickus@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-09-03 08:05:17 +02:00
..
alpha Make do_execve() take a const filename pointer 2010-08-17 18:07:43 -07:00
arm ARM: imx: fix build failure concerning otg/ulpi 2010-08-23 20:50:17 -07:00
avr32 Make do_execve() take a const filename pointer 2010-08-17 18:07:43 -07:00
blackfin Blackfin: wire up new fanotify/prlimit64 syscalls 2010-08-23 04:24:09 -04:00
cris Make do_execve() take a const filename pointer 2010-08-17 18:07:43 -07:00
frv Make do_execve() take a const filename pointer 2010-08-17 18:07:43 -07:00
h8300 Make do_execve() take a const filename pointer 2010-08-17 18:07:43 -07:00
ia64 [IA64] Fix build error: conflicting types for ‘sys_execve’ 2010-08-18 10:17:44 -07:00
m32r Make do_execve() take a const filename pointer 2010-08-17 18:07:43 -07:00
m68k Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/gerg/m68knommu 2010-08-18 09:27:10 -07:00
m68knommu Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/gerg/m68knommu 2010-08-18 09:27:10 -07:00
microblaze Merge branch 'merge-devicetree' of git://git.secretlab.ca/git/linux-2.6 2010-08-18 09:26:17 -07:00
mips Make do_execve() take a const filename pointer 2010-08-17 18:07:43 -07:00
mn10300 arch/mn10300/mm: eliminate NULL dereference 2010-08-23 11:41:24 -07:00
parisc Make do_execve() take a const filename pointer 2010-08-17 18:07:43 -07:00
powerpc powerpc: Fix config dependency problem with MPIC_U3_HT_IRQS 2010-08-24 15:28:29 +10:00
s390 [S390] fix tlb flushing vs. concurrent /proc accesses 2010-08-24 09:26:34 +02:00
score Make do_execve() take a const filename pointer 2010-08-17 18:07:43 -07:00
sh Make do_execve() take a const filename pointer 2010-08-17 18:07:43 -07:00
sparc Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc-2.6 2010-08-24 10:10:13 -07:00
tile Make do_execve() take a const filename pointer 2010-08-17 18:07:43 -07:00
um uml: fix compile error in dma_get_cache_alignment() 2010-08-20 09:34:55 -07:00
x86 perf, x86: Fix accidentally ack'ing a second event on intel perf counter 2010-09-03 08:05:17 +02:00
xtensa Make do_execve() take a const filename pointer 2010-08-17 18:07:43 -07:00
.gitignore
Kconfig Merge branch 'perf/nmi' into perf/core 2010-08-05 08:45:05 +02:00