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| author | Stephane Eranian <eranian@google.com> | 2013-03-15 14:26:07 +0100 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2013-03-15 17:26:35 +0100 |
| commit | 1d9d8639c063caf6efc2447f5f26aa637f844ff6 (patch) | |
| tree | ab9c24ccfd8b464211b393ac8ae9cd6b964e9df3 /arch/x86/power/cpu.c | |
| parent | mm/fremap.c: fix possible oops on error path (diff) | |
| download | linux-1d9d8639c063caf6efc2447f5f26aa637f844ff6.tar.xz linux-1d9d8639c063caf6efc2447f5f26aa637f844ff6.zip | |
perf,x86: fix kernel crash with PEBS/BTS after suspend/resume
This patch fixes a kernel crash when using precise sampling (PEBS)
after a suspend/resume. Turns out the CPU notifier code is not invoked
on CPU0 (BP). Therefore, the DS_AREA (used by PEBS) is not restored properly
by the kernel and keeps it power-on/resume value of 0 causing any PEBS
measurement to crash when running on CPU0.
The workaround is to add a hook in the actual resume code to restore
the DS Area MSR value. It is invoked for all CPUS. So for all but CPU0,
the DS_AREA will be restored twice but this is harmless.
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Stephane Eranian <eranian@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch/x86/power/cpu.c')
| -rw-r--r-- | arch/x86/power/cpu.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/arch/x86/power/cpu.c b/arch/x86/power/cpu.c index 120cee1c3f8d..3c68768d7a75 100644 --- a/arch/x86/power/cpu.c +++ b/arch/x86/power/cpu.c @@ -11,6 +11,7 @@ #include <linux/suspend.h> #include <linux/export.h> #include <linux/smp.h> +#include <linux/perf_event.h> #include <asm/pgtable.h> #include <asm/proto.h> @@ -228,6 +229,7 @@ static void __restore_processor_state(struct saved_context *ctxt) do_fpu_end(); x86_platform.restore_sched_clock_state(); mtrr_bp_restore(); + perf_restore_debug_store(); } /* Needed by apm.c */ |