Hello Vince, On 03/31/2014 09:40 PM, Vince Weaver wrote: > > The Linux 3.14 release adds support for the PERF_FLAG_FD_CLOEXEC flag to > perf_event_open.2 Thanks for the patch. However, I don't find it too clear. Is this flag about setting the c-o-e flag for the file descriptor returned as the return value of perf_event_open()? If so, I think it needs to be worded more clearly to say that/ Could you take a look and resubmit? Thanks, Michael > The wording is based on the description in kernel commit > a21b0b354d4ac39be691f51c53562e2c24443d9e > by Yann Droneaud <ydroneaud@xxxxxxxxxx> > > Signed-off-by: Vince Weaver <vincent.weaver@xxxxxxxxx> > > diff --git a/man2/perf_event_open.2 b/man2/perf_event_open.2 > index 30a2168..46cc204 100644 > --- a/man2/perf_event_open.2 > +++ b/man2/perf_event_open.2 > @@ -164,6 +164,17 @@ must be passed as the > parameter. > cgroup monitoring is available only > for system-wide events and may therefore require extra permissions. > +.TP > +.BR PERF_FLAG_FD_CLOEXEC " (since Linux 3.14)." > +This flag allows atomically setting close-on-exec behavior on > +a created event without needing to call > +.BR fcntl (2). > +This lets userspace remove the file descriptor from the list of > +file descriptors inherited across exec and avoid race conditions > +between the current thread and another calling > +.BR fork (2) > +then > +.BR execve (2). > .P > The > .I perf_event_attr > -- Michael Kerrisk Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/ Linux/UNIX System Programming Training: http://man7.org/training/ -- To unsubscribe from this list: send the line "unsubscribe linux-man" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
