From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dave Jones Subject: Re: [patch] perf_event_open enable sysfs exported events Date: Wed, 19 Jun 2013 12:38:41 -0400 Message-ID: <20130619163841.GA22483@redhat.com> References: <20130619152722.GA22109@redhat.com> Mime-Version: 1.0 Return-path: Content-Disposition: inline In-Reply-To: Sender: trinity-owner@vger.kernel.org List-ID: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Vince Weaver Cc: Tommi Rantala , trinity@vger.kernel.org On Wed, Jun 19, 2013 at 12:34:43PM -0400, Vince Weaver wrote: > On Wed, 19 Jun 2013, Dave Jones wrote: > > > On Thu, Jun 13, 2013 at 03:58:37PM -0400, Vince Weaver wrote: > > > On Thu, 13 Jun 2013, Tommi Rantala wrote: > > > > > > > Unable to opendir /sys/bus/event_source/devices : Resource temporarily > > > > unavailable > > > > > > Though in the case where /sys/bus/event_source/devices isn't available > > > trinity will try opening it again each time it tries to do a > > > PERF_TYPE_READ_FROM_SYSFS type (1 time in 7). Not sure if it's > > > worth rate-limiting that. > > > > I'm puzzled why I'm seeing opendir() fail with -ENOMEM when there's gigabytes > > of free memory available. Likewise, getting -EAGAIN seems.. weird. > > Is this easy to reproduce? I haven't seen it locally but then again > I have only been running trinity with -c perf_event_open > I only left the debug message in because I thought it would be unusual > for a quick sysfs traversal to fail. Hmm, that's weird. When I run with -c perf_event_open it doesn't happen. So it's an interaction with something else that's causing it. Fun. > > init_pmus might be simpler if it was converted to use nftw() too. > > I was unaware of the existence of nftw(), I'll work on updating the code > to use it. I only recently learned of it myself. the tree walking in files.c got a lot simpler. See b0d4df18a6785b0c3347f521bb2c09e88b0c0966. Dave