> -----Original Message----- > From: Daniel P. Berrange [mailto:berrange@xxxxxxxxxx] > Sent: Tuesday, December 8, 2015 6:54 PM > To: Ren, Qiaowei > Cc: libvir-list@xxxxxxxxxx; Jiri Denemark > Subject: Re: [PATCH v2 3/8] perf: implement a set of util functions for perf event > > On Mon, Dec 07, 2015 at 03:53:54PM +0800, Qiaowei Ren wrote: > > This patch implement a set of interfaces for perf event. Based on > > these interfaces, we can implement internal driver API for perf, and > > get the results of perf conuter you care about. > > > > Signed-off-by: Qiaowei Ren <qiaowei.ren@xxxxxxxxx> > > --- > > include/libvirt/virterror.h | 1 + > > src/Makefile.am | 1 + > > src/libvirt_private.syms | 12 ++ > > src/util/virerror.c | 1 + > > src/util/virperf.c | 298 > ++++++++++++++++++++++++++++++++++++++++++++ > > src/util/virperf.h | 61 +++++++++ > > 6 files changed, 374 insertions(+) > > create mode 100644 src/util/virperf.c create mode 100644 > > src/util/virperf.h > > > > > +int > > +virPerfEventDisable(virPerfPtr perf, > > + virPerfEventType type) { > > + virPerfEventPtr event = virPerfGetEvent(perf, type); > > + if (event == NULL) > > + return -1; > > + > > + if (ioctl(event->fd, PERF_EVENT_IOC_DISABLE) < 0) { > > + virReportSystemError(errno, > > + _("Unable to disable perf event type=%d"), > > + event->type); > > + return -1; > > + } > > Since we're closing the file handle next, is there any benefit in doing this ioctl() ? > I guess that VIR_FORCE_CLOSE() will just close the file handle, but the perf event have to be disabled before this. In fact it is from the example in man page of perf_event_open(). Thanks, Qiaowei -- libvir-list mailing list libvir-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/libvir-list