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linux-next/arch
Don Zickus 2bce5daca2 perf, x86, nmi: Move LVT un-masking into irq handlers
It was noticed that P4 machines were generating double NMIs for
each perf event.  These extra NMIs lead to 'Dazed and confused'
messages on the screen.

I tracked this down to a P4 quirk that said the overflow bit had
to be cleared before re-enabling the apic LVT mask.  My first
attempt was to move the un-masking inside the perf nmi handler
from before the chipset NMI handler to after.

This broke Nehalem boxes that seem to like the unmasking before
the counters themselves are re-enabled.

In order to keep this change simple for 2.6.39, I decided to
just simply move the apic LVT un-masking to the beginning of all
the chipset NMI handlers, with the exception of Pentium4's to
fix the double NMI issue.

Later on we can move the un-masking to later in the handlers to
save a number of 'extra' NMIs on those particular chipsets.

I tested this change on a P4 machine, an AMD machine, a Nehalem
box, and a core2quad box.  'perf top' worked correctly along
with various other small 'perf record' runs.  Anything high
stress breaks all the machines but that is a different problem.

Thanks to various people for testing different versions of this
patch.

Reported-and-tested-by: Shaun Ruffell <sruffell@digium.com>
Signed-off-by: Don Zickus <dzickus@redhat.com>
Cc: Cyrill Gorcunov <gorcunov@gmail.com>
Link: http://lkml.kernel.org/r/1303900353-10242-1-git-send-email-dzickus@redhat.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
CC: Cyrill Gorcunov <gorcunov@gmail.com>
2011-04-27 17:59:11 +02:00
..
alpha alpha: Fix uninitialized value in read_persistent_clock. 2011-04-17 14:41:30 -07:00
arm Merge branch 'for-torvalds' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-stericsson 2011-04-25 19:00:55 -07:00
avr32 avr32: add ATAG_BOARDINFO 2011-04-13 15:46:59 +02:00
blackfin Blackfin: SMP: fix cache flush loop 2011-04-13 19:34:06 -04:00
cris Fix common misspellings 2011-03-31 11:26:23 -03:00
frv Fix common misspellings 2011-03-31 11:26:23 -03:00
h8300 genirq: Remove the now obsolete config options and select statements 2011-03-30 14:13:23 +02:00
ia64 Merge branch 'for-linus2' of git://git.profusion.mobi/users/lucas/linux-2.6 2011-04-07 11:14:49 -07:00
m32r Fix common misspellings 2011-03-31 11:26:23 -03:00
m68k m68k,m68knommu: Wire up name_to_handle_at, open_by_handle_at, clock_adjtime, syncfs 2011-04-12 19:02:03 -07:00
microblaze usb: Fix Kconfig unmet dependencies for Microblaze EHCI 2011-04-13 15:43:59 -07:00
mips Fix common misspellings 2011-03-31 11:26:23 -03:00
mn10300 Fix common misspellings 2011-03-31 11:26:23 -03:00
parisc Fix common misspellings 2011-03-31 11:26:23 -03:00
powerpc powerpc/powermac: Build fix with SMP and CPU hotplug 2011-04-18 15:46:35 +10:00
s390 Merge branch 'for-linus' of git://git390.marist.edu/pub/scm/linux-2.6 2011-04-08 07:36:14 -07:00
score Fix common misspellings 2011-03-31 11:26:23 -03:00
sh Merge branch 'fbdev-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/lethal/fbdev-2.6 2011-04-07 12:49:17 -07:00
sparc Merge branch 'for-linus2' of git://git.profusion.mobi/users/lucas/linux-2.6 2011-04-07 11:14:49 -07:00
tile Fix common misspellings 2011-03-31 11:26:23 -03:00
um um: disable CONFIG_CMPXCHG_LOCAL 2011-04-14 16:06:56 -07:00
unicore32 Merge branch 'for-linus2' of git://git.profusion.mobi/users/lucas/linux-2.6 2011-04-07 11:14:49 -07:00
x86 perf, x86, nmi: Move LVT un-masking into irq handlers 2011-04-27 17:59:11 +02:00
xtensa xtensa: Fixup irq conversion fallout and nmi_count 2011-04-20 00:32:09 +02:00
.gitignore
Kconfig oprofile, s390: Cleanups 2011-03-16 14:30:40 +01:00