Hello Wang Nan Thanks for this patch! A few comments below.
On 10/21/2016 01:38 PM, Wang Nan wrote: > Linux 4.7 (86e7972f690c1017fd086cdfe53d8524e68c661c) introduces > PERF_EVENT_IOC_PAUSE_OUTPUT feature. Document it. > > Signed-off-by: Wang Nan <wangn...@huawei.com> > Cc: Michael Kerrisk <mtk.manpa...@gmail.com> > --- > man2/perf_event_open.2 | 13 ++++++++++++- > 1 file changed, 12 insertions(+), 1 deletion(-) > > diff --git a/man2/perf_event_open.2 b/man2/perf_event_open.2 > index fade28c..2d3acad 100644 > --- a/man2/perf_event_open.2 > +++ b/man2/perf_event_open.2 > @@ -2865,7 +2865,18 @@ The argument is a BPF program file descriptor that was > created by > a previous > .BR bpf (2) > system call. > -.SS Using prctl(2) > +.TP > +.BR PERF_EVENT_IOC_PAUSE_OUTPUT " (since Linux 4.7)" > +.\" commit 86e7972f690c1017fd086cdfe53d8524e68c661c > +This allows pausing and resuming the event's ring-buffer. A > +paused ring-buffer does not prevent samples generation, but simply s/samples generation/generation of samples/ > +discards them. The discarded samples are considered lost, causes s/them/the samples/ s/causes/causing/ > +.BR PERF_RECORD_LOST > +to be generated when possible. > + > +The argument is an integer. Nonzero value pauses the ring-buffer, s/Nonzero/a nonzero/ > +zero value resumes the ring-buffer. s/zero value/zero/ > +.SS Using prctl As noted by Vince, the change to this SS line should not be part of this patch. > A process can enable or disable all the event groups that are > attached to it using the > .BR prctl (2) Thanks, Michael -- Michael Kerrisk Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/ Linux/UNIX System Programming Training: http://man7.org/training/
