]> www.infradead.org Git - users/jedix/linux-maple.git/commit
perf tools: Don't set attr.exclude_guest by default
authorNamhyung Kim <namhyung@kernel.org>
Wed, 16 Oct 2024 06:23:52 +0000 (23:23 -0700)
committerNamhyung Kim <namhyung@kernel.org>
Tue, 22 Oct 2024 16:52:11 +0000 (09:52 -0700)
commit35c8d21371e9b342dbd91a8e9b1abaabaec95d41
tree1c88572680fc2c2196ef36cc82f741d9aec31dd1
parentbb6e7cb11d97ce1957894d30d13bfad3e8bfefe9
perf tools: Don't set attr.exclude_guest by default

The exclude_guest in the event attribute is to limit profiling in the
host environment.  But I'm not sure why we want to set it by default
cause we don't care about it in most cases and I feel like it just
makes new PMU implementation complicated.

Of course it's useful for perf kvm command so I added the
exclude_GH_default variable to preserve the old behavior for perf kvm
and other commands like perf record and stat won't set the exclude bit.
This is helpful for AMD IBS case since having exclude_guest bit will
clear new feature bit due to the missing feature check logic.

  $ sysctl kernel.perf_event_paranoid
  kernel.perf_event_paranoid = 0

  $ perf record -W -e ibs_op// -vv true 2>&1 | grep switching
  switching off PERF_FORMAT_LOST support
  switching off weight struct support
  switching off bpf_event
  switching off ksymbol
  switching off cloexec flag
  switching off mmap2
  switching off exclude_guest, exclude_host

Intestingly, I found it sets the exclude_bit if "u" modifier is used.
I don't know why but it's neither intuitive nor consistent.  Let's
remove the bit there too.

Reviewed-by: Ian Rogers <irogers@google.com>
Reviewed-by: James Clark <james.clark@linaro.org>
Reviewed-by: Ravi Bangoria <ravi.bangoria@amd.com>
Acked-by: Kan Liang <kan.liang@linux.intel.com>
Cc: James Clark <james.clark@arm.com>
Cc: Atish Patra <atishp@atishpatra.org>
Cc: Mingwei Zhang <mizhang@google.com>
Cc: Kajol Jain <kjain@linux.ibm.com>
Cc: Thomas Richter <tmricht@linux.ibm.com>
Cc: Palmer Dabbelt <palmer@rivosinc.com>
Link: https://lore.kernel.org/r/20241016062359.264929-3-namhyung@kernel.org
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
tools/perf/builtin-kvm.c
tools/perf/tests/parse-events.c
tools/perf/tests/shell/attr/test-record-dummy-C0
tools/perf/util/parse-events.c
tools/perf/util/util.c
tools/perf/util/util.h