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ea15483e7c
Add 'simd' sort field to visualize SIMD ops in 'perf report'.
Rows are labeled with the SIMD ISA, and the type of predicate (if any):
- [p] partial predicate
- [e] empty predicate (no elements in the vector being used)
Example with Arm SPE and SVE (Scalable Vector Extension):
#include <arm_sve.h>
double src[1025], dst[1025];
int main(void) {
svfloat64_t vc = svdup_f64(1);
for(;;)
for(int i = 0; i < 1025; i += svcntd())
{
svbool_t pg = svwhilelt_b64(i, 1025);
svfloat64_t vsrc = svld1(pg, &src[i]);
svfloat64_t vdst = svadd_x(pg, vsrc, vc);
svst1(pg, &dst[i], vdst);
}
return 0;
}
... compiled using "gcc-11 -march=armv8-a+sve -O3"
Profiling on a platform that implements FEAT_SVE and FEAT_SPEv1p1:
$ perf record -e arm_spe_0// -- ./a.out
$ perf report --itrace=i1i -s overhead,pid,simd,sym
Overhead Pid:Command Simd Symbol
........ ................ ....... ......................
53.76% 10758:program [.] main
46.14% 10758:program [.] SVE [.] main
0.09% 10758:program [p] SVE [.] main
The report shows 0.09% of the sampled SVE operations use partial
predicates due to src and dst arrays not being multiples of the vector
register lengths.
Signed-off-by: German Gomez <german.gomez@arm.com>
Acked-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Anshuman.Khandual@arm.com
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: John Garry <john.g.garry@oracle.com>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mike Leach <mike.leach@linaro.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will@kernel.org>
Cc: linux-arm-kernel@lists.infradead.org
Link: https://lore.kernel.org/r/20230320151509.1137462-2-james.clark@arm.com
Signed-off-by: James Clark <james.clark@arm.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.