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| author | Ingo Molnar <mingo@kernel.org> | 2016-07-10 20:58:36 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2016-07-10 20:58:36 +0200 |
| commit | 44530d588e142a96cf0cd345a7cb8911c4f88720 (patch) | |
| tree | f1b2a9d46904fd3479c320267691ee89d172b3dc /arch | |
| parent | 46866b59dfbe9bf99bb1323ce1f3fd2073a81aa3 (diff) | |
| download | linux-44530d588e142a96cf0cd345a7cb8911c4f88720.tar.bz2 | |
Revert "perf/x86/intel, watchdog: Switch NMI watchdog to ref cycles on x86"
This reverts commit 2c95afc1e83d93fac3be6923465e1753c2c53b0a.
Stephane reported the following regression:
> Since Andi added:
>
> commit 2c95afc1e83d93fac3be6923465e1753c2c53b0a
> Author: Andi Kleen <ak@linux.intel.com>
> Date: Thu Jun 9 06:14:38 2016 -0700
>
> perf/x86/intel, watchdog: Switch NMI watchdog to ref cycles on x86
>
> $ perf stat -e ref-cycles ls
> <not counted> ....
>
> fails systematically because the ref-cycles is now used by the
> watchdog and given this is a system-wide pinned event, it monopolizes
> the fixed counter 2 which is the only counter able to measure this event.
Since the next merge window is near, fix the regression for now
by reverting the commit.
Reported-by: Stephane Eranian <eranian@google.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86/kernel/apic/hw_nmi.c | 8 |
1 files changed, 0 insertions, 8 deletions
diff --git a/arch/x86/kernel/apic/hw_nmi.c b/arch/x86/kernel/apic/hw_nmi.c index 016f4263fad4..7788ce643bf4 100644 --- a/arch/x86/kernel/apic/hw_nmi.c +++ b/arch/x86/kernel/apic/hw_nmi.c @@ -18,16 +18,8 @@ #include <linux/nmi.h> #include <linux/module.h> #include <linux/delay.h> -#include <linux/perf_event.h> #ifdef CONFIG_HARDLOCKUP_DETECTOR -int hw_nmi_get_event(void) -{ - if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL) - return PERF_COUNT_HW_REF_CPU_CYCLES; - return PERF_COUNT_HW_CPU_CYCLES; -} - u64 hw_nmi_get_sample_period(int watchdog_thresh) { return (u64)(cpu_khz) * 1000 * watchdog_thresh; |