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=-5.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham 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 60019CA9EB9 for ; Wed, 23 Oct 2019 22:37:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3BBFE205F4 for ; Wed, 23 Oct 2019 22:37:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2407930AbfJWWhF (ORCPT ); Wed, 23 Oct 2019 18:37:05 -0400 Received: from mga05.intel.com ([192.55.52.43]:51990 "EHLO mga05.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2405969AbfJWWhF (ORCPT ); Wed, 23 Oct 2019 18:37:05 -0400 X-Amp-Result: UNKNOWN X-Amp-Original-Verdict: FILE UNKNOWN X-Amp-File-Uploaded: False Received: from orsmga005.jf.intel.com ([10.7.209.41]) by fmsmga105.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 23 Oct 2019 15:37:04 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.68,222,1569308400"; d="scan'208";a="373024319" Received: from tassilo.jf.intel.com (HELO tassilo.localdomain) ([10.7.201.137]) by orsmga005.jf.intel.com with ESMTP; 23 Oct 2019 15:37:04 -0700 Received: by tassilo.localdomain (Postfix, from userid 1000) id 6A14730038C; Wed, 23 Oct 2019 15:37:04 -0700 (PDT) Date: Wed, 23 Oct 2019 15:37:04 -0700 From: Andi Kleen To: Alexey Budankov Cc: Andi Kleen , Jiri Olsa , acme@kernel.org, linux-kernel@vger.kernel.org, jolsa@kernel.org, eranian@google.com, kan.liang@linux.intel.com, peterz@infradead.org Subject: Re: [PATCH v2 4/9] perf affinity: Add infrastructure to save/restore affinity Message-ID: <20191023223704.GI4660@tassilo.jf.intel.com> References: <20191020175202.32456-1-andi@firstfloor.org> <20191020175202.32456-5-andi@firstfloor.org> <20191023095911.GJ22919@krava> <20191023130235.GF4660@tassilo.jf.intel.com> <20191023143049.GS22919@krava> <20191023145206.GH4660@tassilo.jf.intel.com> <6ac1024c-bc73-87cd-31d2-819abee60137@linux.intel.com> <20191023171904.ft735ormkro6tahp@two.firstfloor.org> <346239e4-f156-01bb-4e42-85db289c476b@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <346239e4-f156-01bb-4e42-85db289c476b@linux.intel.com> User-Agent: Mutt/1.12.1 (2019-06-15) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Oct 23, 2019 at 09:08:47PM +0300, Alexey Budankov wrote: > On 23.10.2019 20:19, Andi Kleen wrote: > > On Wed, Oct 23, 2019 at 07:16:13PM +0300, Alexey Budankov wrote: > >> > >> On 23.10.2019 17:52, Andi Kleen wrote: > >>> On Wed, Oct 23, 2019 at 04:30:49PM +0200, Jiri Olsa wrote: > >>>> On Wed, Oct 23, 2019 at 06:02:35AM -0700, Andi Kleen wrote: > >>>>> On Wed, Oct 23, 2019 at 11:59:11AM +0200, Jiri Olsa wrote: > >>>>>> On Sun, Oct 20, 2019 at 10:51:57AM -0700, Andi Kleen wrote: > >>>>>> > >>>>>> SNIP > >>>>>> > >>>>>>> +} > >>>>>>> diff --git a/tools/perf/util/affinity.h b/tools/perf/util/affinity.h > >>>>>>> new file mode 100644 > >>>>>>> index 000000000000..e56148607e33 > >>>>>>> --- /dev/null > >>>>>>> +++ b/tools/perf/util/affinity.h > >>>>>>> @@ -0,0 +1,15 @@ > >>>>>>> +// SPDX-License-Identifier: GPL-2.0 > >>>>>>> +#ifndef AFFINITY_H > >>>>>>> +#define AFFINITY_H 1 > >>>>>>> + > >>>>>>> +struct affinity { > >>>>>>> + unsigned char *orig_cpus; > >>>>>>> + unsigned char *sched_cpus; > >>>>>> > >>>>>> why not use cpu_set_t directly? > >>>>> > >>>>> Because it's too small in glibc (only 1024 CPUs) and perf already > >>>>> supports more. > >>>> > >>>> nice, we're using it all over the place.. how about using bitmap_alloc? > >>> > >>> Okay. > >>> > >>> The other places is mainly perf record from Alexey's recent affinity changes. > >>> These probably need to be fixed. > >>> > >>> +Alexey > >> > >> Despite the issue indeed looks generic for stat and record modes, > >> have you already observed record startup overhead somewhere in your setups? > >> I would, first, prefer to reproduce the overhead, to have stable use case > >> for evaluation and then, possibly, improvement. > > > > What I meant the cpu_set usages you added in > > > > commit 9d2ed64587c045304efe8872b0258c30803d370c > > Author: Alexey Budankov > > Date: Tue Jan 22 20:47:43 2019 +0300 > > > > perf record: Allocate affinity masks > > > > need to be fixed to allocate dynamically, or at least use MAX_NR_CPUs to > > support systems with >1024CPUs. That's an independent functionality > > problem. > > Oh, it is clear now. Thanks for pointing this out. For that to move from > cpu_mask_t to new custom struct affinity type its API requires extension > to provide mask operations similar to the ones that cpu_mask_t provides: > CPU_ZERO(), CPU_SET(), CPU_EQUAL(), CPU_OR(). > > For example it could be like: affinity__mask_zero(), affinity__mask_set(), > affinity__mask_equal(), affinity__mask_or() and then the collecting part > of record could also be moved to struct affinity type and overcome >1024CPUs > limitation. Not sure you need to use my library, except perhaps the get_cpu_set_size() function. It is somewhat specialized. Everything else you can use normal Linux bitmap functions, or call the sys call directly. -Andi