From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 55401C388F7 for ; Tue, 10 Nov 2020 18:55:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D7E7320797 for ; Tue, 10 Nov 2020 18:55:10 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="pyeasDgM" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731263AbgKJSzJ (ORCPT ); Tue, 10 Nov 2020 13:55:09 -0500 Received: from mail.kernel.org ([198.145.29.99]:44666 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730468AbgKJSzJ (ORCPT ); Tue, 10 Nov 2020 13:55:09 -0500 Received: from quaco.ghostprotocols.net (unknown [179.97.37.151]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 25A27206F1; Tue, 10 Nov 2020 18:55:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1605034508; bh=jGMJQVhOYYbu7V3KA7lkuZA03vlDOae9KFulBxXATsE=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=pyeasDgMpFMhwi4L4dxPrzhjp+0Yom/pzkyA7ZyoXSWyRGQIWX/ldDCQFi2fHVXBI XyDjKj/7sETDCEAbCDVhD/lOkHtfgcHj+H19C0YE5UlY5DiT3zT7Y+vAZOoEI1AM7f 5INt1AT7gAK2y5iWgwTcIPhBasJ3/FByhoMnisUM= Received: by quaco.ghostprotocols.net (Postfix, from userid 1000) id 20B8D411D1; Tue, 10 Nov 2020 15:55:06 -0300 (-03) Date: Tue, 10 Nov 2020 15:55:06 -0300 From: Arnaldo Carvalho de Melo To: Jiri Olsa Cc: Peter Zijlstra , Jiri Olsa , lkml , Ingo Molnar , Mark Rutland , Namhyung Kim , Alexander Shishkin , Michael Petlan , Song Liu , Ian Rogers , Stephane Eranian , Alexey Budankov , Andi Kleen , Adrian Hunter Subject: Re: [PATCH 03/24] perf: Add build id data in mmap2 event Message-ID: <20201110185506.GB26034@kernel.org> References: <20201109215415.400153-1-jolsa@kernel.org> <20201109215415.400153-4-jolsa@kernel.org> <20201110082851.GV2594@hirez.programming.kicks-ass.net> <20201110101041.GC387652@krava> <20201110182334.GG387652@krava> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20201110182334.GG387652@krava> X-Url: http://acmel.wordpress.com Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Em Tue, Nov 10, 2020 at 07:23:34PM +0100, Jiri Olsa escreveu: > On Tue, Nov 10, 2020 at 11:10:46AM +0100, Jiri Olsa wrote: > > On Tue, Nov 10, 2020 at 09:28:51AM +0100, Peter Zijlstra wrote: > > > On Mon, Nov 09, 2020 at 10:53:54PM +0100, Jiri Olsa wrote: > > > > There's new misc bit for mmap2 to signal there's build > > > > id data in it: > > > > > > > > #define PERF_RECORD_MISC_BUILD_ID (1 << 14) > > > > > > PERF_RECORD_MISC_MMAP_BUILD_ID would be consistent with the existing > > > PERF_RECORD_MISC_MMAP_DATA naming. Agreed. > > ok > > > > > > Also, AFAICT there's still a bunch of unused bits in misc. > > > > > > 012 CDEF > > > |||---------|||| > > > > > > Where: > > > 0-2 CPUMODE_MASK > > > > > > C PROC_MAP_PARSE_TIMEOUT > > > D MMAP_DATA / COMM_EXEC / FORK_EXEC / SWITCH_OUT > > > E EXACT_IP / SCHED_OUT_PREEMPT > > > F (reserved) > > > > > > Maybe we should put in a comment to keep track of the hole ? > > > > ook > > how about the change below.. I also switch the build_id with the size, > but I kept the build_id size 20, because I think there's bigger chance > we will use those reserved bytes for something, than that we will need > those extra 3 bytes in build_id array > > struct { > u8 build_id_size; > u8 __reserved_1; > u16 __reserved_2; > u8 build_id[20]; > }; For "maybe we'll use it for something else" doesn't require that it gets before build_id, i.e. to use it for something else it can be as above or struct { u8 build_id_size; u8 build_id[20]; u8 __reserved_1; u16 __reserved_2; }; that groups build_id size with it, but nah, this is getting funny by now. My suggestion was not about increasing build_id to 23, just to leave the unused (reserved) bytes after it. - Arnaldo