From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754656AbaILN7H (ORCPT ); Fri, 12 Sep 2014 09:59:07 -0400 Received: from foss-mx-na.foss.arm.com ([217.140.108.86]:32894 "EHLO foss-mx-na.foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752965AbaILN7F (ORCPT ); Fri, 12 Sep 2014 09:59:05 -0400 Message-ID: <1410530335.16936.60.camel@hornet> Subject: Re: [RFC 2/2] perf: Marker software event and ioctl From: Pawel Moll To: Arnaldo Carvalho de Melo Cc: Christopher Covington , Richard Cochran , Steven Rostedt , Ingo Molnar , Peter Zijlstra , Paul Mackerras , John Stultz , "linux-kernel@vger.kernel.org" , "linux-api@vger.kernel.org" Date: Fri, 12 Sep 2014 14:58:55 +0100 In-Reply-To: <20140912134910.GG1801@kernel.org> References: <1410522513-1045-1-git-send-email-pawel.moll@arm.com> <1410522513-1045-3-git-send-email-pawel.moll@arm.com> <5412EA7A.9020807@codeaurora.org> <1410526672.16936.52.camel@hornet> <20140912134910.GG1801@kernel.org> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.10.4-0ubuntu2 Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 2014-09-12 at 14:49 +0100, Arnaldo Carvalho de Melo wrote: > Perhaps both? I.e. an u64 followed from a string, if the u64 is zero, > then there is a string right after it? How would this look like in userspace? Something like this? 8<---- struct perf_event_marker { uint64_t value; char *string; } arg; arg.value = 0x1234; /* or */ arg.value = 0; arg.string = "abcd"; ioctl(fd, PERF_EVENT_IOC_MARKER, &arg) 8<---- If so, maybe it would simpler just to go for classic size/data structure? 8<----- struct perf_event_marker { uint32_t size; void *data; } 8<----- This would directly map into struct perf_raw_record... Paweł