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| author | Peter Zijlstra <peterz@infradead.org> | 2018-11-20 18:08:42 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2018-11-20 18:57:48 +0100 |
| commit | 2a5bf23d5b795d5df33dc284e8f5cf8b6a5b4042 (patch) | |
| tree | a8e7207d6415cc41b8458be461909c05abf0062c /Documentation/admin-guide/kernel-parameters.txt | |
| parent | 9ff01193a20d391e8dbce4403dd5ef87c7eaaca6 (diff) | |
| download | lwn-2a5bf23d5b795d5df33dc284e8f5cf8b6a5b4042.tar.gz lwn-2a5bf23d5b795d5df33dc284e8f5cf8b6a5b4042.zip | |
perf/x86/intel: Fix regression by default disabling perfmon v4 interrupt handling
Kyle Huey reported that 'rr', a replay debugger, broke due to the following commit:
af3bdb991a5c ("perf/x86/intel: Add a separate Arch Perfmon v4 PMI handler")
Rework the 'disable_counter_freezing' __setup() parameter such that we
can explicitly enable/disable it and switch to default disabled.
To this purpose, rename the parameter to "perf_v4_pmi=" which is a much
better description and allows requiring a bool argument.
[ mingo: Improved the changelog some more. ]
Reported-by: Kyle Huey <me@kylehuey.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Robert O'Callahan <robert@ocallahan.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: acme@kernel.org
Link: http://lkml.kernel.org/r/20181120170842.GZ2131@hirez.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'Documentation/admin-guide/kernel-parameters.txt')
| -rw-r--r-- | Documentation/admin-guide/kernel-parameters.txt | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 81d1d5a74728..5463d5a4d85c 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -856,7 +856,8 @@ causing system reset or hang due to sending INIT from AP to BSP. - disable_counter_freezing [HW] + perf_v4_pmi= [X86,INTEL] + Format: <bool> Disable Intel PMU counter freezing feature. The feature only exists starting from Arch Perfmon v4 (Skylake and newer). |