linux/arch/x86
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
..
boot x86, setup: move isdigit.h to ctype.h, header files on top. 2010-08-02 21:07:20 -07:00
configs defconfig reduction 2010-08-14 22:26:53 +02:00
crypto Merge git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6 2010-05-03 11:28:58 +08:00
ia32 Mark arguments to certain syscalls as being const 2010-08-13 16:53:13 -07:00
include/asm Merge branch 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2010-08-20 14:25:08 -07:00
kernel perf, x86: Fix accidentally ack'ing a second event on intel perf counter 2010-09-03 08:05:17 +02:00
kvm Merge branch 'kvm-updates/2.6.36' of git://git.kernel.org/pub/scm/virt/kvm/kvm 2010-08-22 11:27:36 -07:00
lguest Merge branch 'ht-delete-2.6.35' into release 2010-05-28 16:20:35 -04:00
lib Merge branch 'x86/urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2010-08-13 10:35:48 -07:00
math-emu x86, fpu: Unbreak FPU emulation 2010-05-10 13:37:16 -07:00
mm x86: don't send SIGBUS for kernel page faults 2010-08-13 09:49:20 -07:00
oprofile oprofile, x86: fix init_sysfs() function stub 2010-09-01 21:23:01 +02:00
pci x86/PCI: use for_each_pci_dev() 2010-07-30 09:47:33 -07:00
power update email address 2010-07-19 10:56:54 +02:00
tools x86: Remove trailing spaces in messages 2010-02-07 17:47:51 +01:00
vdso Merge branches 'x86-cleanups-for-linus', 'x86-vmware-for-linus', 'x86-mtrr-for-linus', 'x86-apic-for-linus', 'x86-fpu-for-linus' and 'x86-vdso-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2010-08-06 16:22:59 -07:00
video
xen xen: pvhvm: rename xen_emul_unplug=ignore to =unnnecessary 2010-08-23 11:59:29 +01:00
.gitignore add random binaries to .gitignore 2010-04-08 11:34:34 +02:00
Kbuild
Kconfig Replace Configure with Enable in description of MAXSMP 2010-08-21 12:38:58 -07:00
Kconfig.cpu Merge branch 'x86-fpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2010-05-18 08:58:16 -07:00
Kconfig.debug Merge branch 'x86-cleanups-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2010-05-18 08:40:21 -07:00
Makefile x86: Use .cfi_sections for assembly code 2010-05-13 22:15:18 -07:00
Makefile_32.cpu Merge branch 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2009-12-08 13:38:11 -08:00