From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pawel Moll Subject: Re: [PATCH 2/2] perf: Userspace software event and ioctl Date: Mon, 29 Sep 2014 16:53:23 +0100 Message-ID: <1412006003.3817.30.camel@hornet> References: <1411050873-9310-1-git-send-email-pawel.moll@arm.com> <1411050873-9310-3-git-send-email-pawel.moll@arm.com> <20140929153257.GM4140@worktop.programming.kicks-ass.net> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20140929153257.GM4140-IIpfhp3q70z/8w/KjCw3T+5/BudmfyzbbVWyRVo5IupeoWH0uzbU5w@public.gmane.org> Sender: linux-api-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Peter Zijlstra Cc: Richard Cochran , Steven Rostedt , Ingo Molnar , Paul Mackerras , Arnaldo Carvalho de Melo , John Stultz , "linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "linux-api-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" List-Id: linux-api@vger.kernel.org On Mon, 2014-09-29 at 16:32 +0100, Peter Zijlstra wrote: > Also none of the many words above describe > PERF_SAMPLE_USERSPACE_EVENT(), wth is that about? Hopefully description of the v2 makes better job in this: http://thread.gmane.org/gmane.linux.kernel/1793272/focus=4813 where it's already called "UEVENT" and was generated by write(). Before you get into this, though, the most important outcomes of both v1 and v2 discussions: * Ingo suggested prctl(PR_TRACE_UEVENT, type, size, data, 0) as the way of generating such events (so the tracee doesn't have to know the fd to do ioctl); Frederic seems to have the same on his mind. * Namhyung proposed sticking the userspace-originating events into the buffer as PERF_RECORD_UEVENT rather then PERF_SAMPLE_UEVENT. Working on making both happen now. Pawel