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2c2a9bbe7f
linux/arch/x86/events
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Kan Liang 2c2a9bbe7f perf/x86/intel: Disable userspace RDPMC usage for large PEBS 
Userspace RDPMC cannot possibly work for large PEBS, which was introduced in:

  b8241d2069 ("perf/x86/intel: Implement batched PEBS interrupt handling (large PEBS interrupt threshold)")

When the PEBS interrupt threshold is larger than one, there is no way
to get exact auto-reload times and value for userspace RDPMC.  Disable
the userspace RDPMC usage when large PEBS is enabled.

The only exception is when the PEBS interrupt threshold is 1, in which
case user-space RDPMC works well even with auto-reload events.

Signed-off-by: Kan Liang <kan.liang@linux.intel.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: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: acme@kernel.org
Fixes: b8241d2069 ("perf/x86/intel: Implement batched PEBS interrupt handling (large PEBS interrupt threshold)")
Link: http://lkml.kernel.org/r/1518474035-21006-6-git-send-email-kan.liang@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
(cherry picked from commit 1af22eba24)
2018-03-20 08:52:58 +01:00
..
amd perf/x86/amd/power: Do not load AMD power module on !AMD platforms 2018-01-24 13:00:35 +01:00
intel perf/x86/intel/uncore: Fix Skylake UPI event format 2018-03-04 09:59:00 +01:00
core.c perf/x86/intel: Disable userspace RDPMC usage for large PEBS 2018-03-20 08:52:58 +01:00
Kconfig License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
Makefile perf/x86/events: Add an AMD-specific Makefile 2017-01-30 12:01:19 +01:00
msr.c perf/x86/msr: Clean up the code 2018-01-06 12:18:40 +01:00
perf_event.h x86/events/intel/ds: Add PERF_SAMPLE_PERIOD into PEBS_FREERUNNING_FLAGS 2018-02-05 13:48:44 -03:00