From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754776AbaI2Pxj (ORCPT ); Mon, 29 Sep 2014 11:53:39 -0400 Received: from foss-mx-na.foss.arm.com ([217.140.108.86]:39093 "EHLO foss-mx-na.foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754143AbaI2Pxg (ORCPT ); Mon, 29 Sep 2014 11:53:36 -0400 Message-ID: <1412006003.3817.30.camel@hornet> Subject: Re: [PATCH 2/2] perf: Userspace software event and ioctl From: Pawel Moll To: Peter Zijlstra Cc: Richard Cochran , Steven Rostedt , Ingo Molnar , Paul Mackerras , Arnaldo Carvalho de Melo , John Stultz , "linux-kernel@vger.kernel.org" , "linux-api@vger.kernel.org" Date: Mon, 29 Sep 2014 16:53:23 +0100 In-Reply-To: <20140929153257.GM4140@worktop.programming.kicks-ass.net> 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> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.10.4-0ubuntu2 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@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