perf/x86/intel/pt: Opportunistically use single range output mode

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Most of PT implementations support Single Range Output mode, which is
an alternative to ToPA that can be used for a single contiguous buffer
and if we don't require an interrupt, that is, in AUX snapshot mode.

Now that perf core will use high order allocations for the AUX buffer,
in many cases the first condition will also be satisfied.

The two most obvious benefits of the Single Range Output mode over the
ToPA are:

 * not having to allocate the ToPA table(s),
 * not using the ToPA walk hardware.

Make use of this functionality where available and appropriate.

Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Link: https://lkml.kernel.org/r/20191105082701.78442-2-alexander.shishkin@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

...

This commit is contained in:

Alexander Shishkin 2019-11-05 10:27:00 +02:00 • committed by Ingo Molnar

parent 25e8920b30

commit 670638477a

2 changed files with 92 additions and 28 deletions

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118

arch/x86/events/intel/pt.c

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2

arch/x86/events/intel/pt.h

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