Messages in this thread |  | | Subject | Re: [PATCH 0/2] perf: Allow closing siblings' file descriptors | From | Alexey Budankov <> | Date | Thu, 9 Jul 2020 11:30:34 +0300 |
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Hi Alex,
On 08.07.2020 18:16, Alexander Shishkin wrote: > 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.
PERF_EVENT_IOC_ENABLE, PERF_EVENT_IOC_DISABLE ioctls are still assumed to work, right?
Asking w.r.t. functionality on --control fd:ctl_fd[,ack_fd] option for stat and record modes [1].
Thanks, Alexey
[1] https://lore.kernel.org/lkml/4af50c95-36f6-7a61-5a22-2949970fe7a5@linux.intel.com/
> > 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(-) >
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