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Subject[PATCH 0/2] perf: Allow closing siblings' file descriptors
Date
Hi guys,

I've been looking at reducing the number of open file descriptors per perf
session. If we retain one descriptor per event, in a large group they add
up. At the same time, we're not actually using them for anything after the
SET_OUTPUT and maybe SET_FILTER ioctls. So, this series is a stab at that.

So, I added a new flag to the perf_event_open() that tells perf to keep
the event around after its file descriptor gets closed, for as long as its
group leader is alive. Since this is a new behavior, the flag is an opt-in.

I also hacked this into the perf tool (mostly perf record, but I'll hack
stat as well if this general approach is agreeable).

Alexander Shishkin (2):
perf: Add closing sibling events' file descriptors
perf record: Support closing siblings' file descriptors

include/linux/perf_event.h | 7 ++
include/uapi/linux/perf_event.h | 1 +
kernel/events/core.c | 149 +++++++++++++++++-------
tools/include/uapi/linux/perf_event.h | 1 +
tools/lib/perf/evlist.c | 30 ++++-
tools/lib/perf/evsel.c | 21 ++++
tools/lib/perf/include/internal/evsel.h | 4 +
tools/perf/builtin-record.c | 48 ++++++--
tools/perf/util/cpumap.c | 4 +
tools/perf/util/evlist.c | 4 +-
tools/perf/util/evsel.c | 17 ++-
tools/perf/util/evsel.h | 3 +
12 files changed, 234 insertions(+), 55 deletions(-)

--
2.27.0

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