linux_dsm_epyc7002/arch
Peter Zijlstra 45e16a6834 perf, x86: Fix hw_perf_enable() event assignment
What happens is that we schedule badly like:

<...>-1987  [019]   280.252808: x86_pmu_start: event-46/1300c0: idx: 0
<...>-1987  [019]   280.252811: x86_pmu_start: event-47/1300c0: idx: 1
<...>-1987  [019]   280.252812: x86_pmu_start: event-48/1300c0: idx: 2
<...>-1987  [019]   280.252813: x86_pmu_start: event-49/1300c0: idx: 3
<...>-1987  [019]   280.252814: x86_pmu_start: event-50/1300c0: idx: 32
<...>-1987  [019]   280.252825: x86_pmu_stop: event-46/1300c0: idx: 0
<...>-1987  [019]   280.252826: x86_pmu_stop: event-47/1300c0: idx: 1
<...>-1987  [019]   280.252827: x86_pmu_stop: event-48/1300c0: idx: 2
<...>-1987  [019]   280.252828: x86_pmu_stop: event-49/1300c0: idx: 3
<...>-1987  [019]   280.252829: x86_pmu_stop: event-50/1300c0: idx: 32
<...>-1987  [019]   280.252834: x86_pmu_start: event-47/1300c0: idx: 1
<...>-1987  [019]   280.252834: x86_pmu_start: event-48/1300c0: idx: 2
<...>-1987  [019]   280.252835: x86_pmu_start: event-49/1300c0: idx: 3
<...>-1987  [019]   280.252836: x86_pmu_start: event-50/1300c0: idx: 32
<...>-1987  [019]   280.252837: x86_pmu_start: event-51/1300c0: idx: 32 *FAIL*

This happens because we only iterate the n_running events in the first
pass, and reset their index to -1 if they don't match to force a
re-assignment.

Now, in our RR example, n_running == 0 because we fully unscheduled, so
event-50 will retain its idx==32, even though in scheduling it will have
gotten idx=0, and we don't trigger the re-assign path.

The easiest way to fix this is the below patch, which simply validates
the full assignment in the second pass.

Reported-by: Stephane Eranian <eranian@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1268311069.5037.31.camel@laptop>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-03-11 15:21:28 +01:00
..
alpha alpha: PTR_ERR overwrites -EINVAL in syscall osf_mount 2010-03-06 11:26:27 -08:00
arm perf: Provide generic perf_sample_data initialization 2010-03-10 13:22:23 +01:00
avr32 USB: atmel uaba: Adding invert vbus_pin 2010-03-02 14:54:57 -08:00
blackfin Merge branch 'master' into percpu 2010-02-02 14:38:15 +09:00
cris cris v32: typo in crisv32_arbiter_unwatch()? 2010-03-06 11:26:28 -08:00
frv frv: remove pci_dma_sync_single() and pci_dma_sync_sg() 2010-03-06 11:26:27 -08:00
h8300 m68k{,nommu}/h8300: Remove obsolete comment about map_chunk 2010-02-27 18:27:14 +01:00
ia64 Driver core: Constify struct sysfs_ops in struct kobj_type 2010-03-07 17:04:49 -08:00
m32r Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu 2010-03-03 07:34:18 -08:00
m68k Merge branch 'for-linus' of master.kernel.org:/home/rmk/linux-2.6-arm 2010-03-01 09:15:15 -08:00
m68knommu m68knommu: NPTL support for uClinux 2010-02-27 18:35:22 +01:00
microblaze Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu 2010-03-03 07:34:18 -08:00
mips sysdev: Pass attribute in sysdev_class attributes show/store 2010-03-07 17:04:47 -08:00
mn10300 Merge branch 'for-linus' of master.kernel.org:/home/rmk/linux-2.6-arm 2010-03-01 09:15:15 -08:00
parisc parisc: use __ratelimit in unaligned.c 2010-03-06 22:54:59 +00:00
powerpc perf, ppc: Fix compile error due to new cpu notifiers 2010-03-11 15:21:27 +01:00
s390 Merge git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core-2.6 2010-03-08 10:17:20 -08:00
score Merge branch 'for-linus' of master.kernel.org:/home/rmk/linux-2.6-arm 2010-03-01 09:15:15 -08:00
sh perf: Rework and fix the arch CPU-hotplug hooks 2010-03-10 13:22:24 +01:00
sparc perf: Provide generic perf_sample_data initialization 2010-03-10 13:22:23 +01:00
um elf coredump: add extended numbering support 2010-03-06 11:26:46 -08:00
x86 perf, x86: Fix hw_perf_enable() event assignment 2010-03-11 15:21:28 +01:00
xtensa Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next-2.6 2010-03-02 07:55:08 -08:00
.gitignore
Kconfig Merge branch 'perf-probes-for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2010-03-05 10:50:22 -08:00