From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755100Ab2EXJvD (ORCPT ); Thu, 24 May 2012 05:51:03 -0400 Received: from merlin.infradead.org ([205.233.59.134]:50572 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754465Ab2EXJvB (ORCPT ); Thu, 24 May 2012 05:51:01 -0400 Subject: Re: [PATCH 02/16] perf: Add ability to attach registers dump to sample From: Peter Zijlstra To: Jiri Olsa Cc: acme@redhat.com, mingo@elte.hu, paulus@samba.org, cjashfor@linux.vnet.ibm.com, fweisbec@gmail.com, eranian@google.com, gorcunov@openvz.org, tzanussi@gmail.com, mhiramat@redhat.com, robert.richter@amd.com, fche@redhat.com, linux-kernel@vger.kernel.org, masami.hiramatsu.pt@hitachi.com, drepper@gmail.com, asharma@fb.com, benjamin.redelings@nescent.org In-Reply-To: <1337801535-12865-3-git-send-email-jolsa@redhat.com> References: <1337801535-12865-1-git-send-email-jolsa@redhat.com> <1337801535-12865-3-git-send-email-jolsa@redhat.com> Content-Type: text/plain; charset="UTF-8" Date: Thu, 24 May 2012 11:50:48 +0200 Message-ID: <1337853048.9783.92.camel@laptop> Mime-Version: 1.0 X-Mailer: Evolution 2.32.2 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 2012-05-23 at 21:32 +0200, Jiri Olsa wrote: > /* > + * Values for sample_regs when PERF_SAMPLE_REGS is set. > + * Defines register set to be attached to the sample. > + */ > +enum perf_sample_regs { > + PERF_SAMPLE_REGS_USER = 1U << 0, /* user registers */ > + PERF_SAMPLE_REGS_MAX = 1U << 1, /* non-ABI */ > +}; > + __u64 sample_regs; /* enum perf_sample_regs */ > + > + /* > + * Arch specific mask for PERF_SAMPLE_REGS_USER setup. > + * Defines set of user regs to dump on samples. > + * See asm/perf_regs.h for details. > + */ > + __u64 sample_regs_user; This all just smells.. :/ So you're wasting 64 bits to specify PERF_SAMPLE_REGS_USER while also implying we'll need another u64 for every other value of perf_sample_regs? What are we doing here and why?