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,URIBL_BLOCKED, 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 DC71ECA9EB6 for ; Wed, 23 Oct 2019 18:08:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BC8442173B for ; Wed, 23 Oct 2019 18:08:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388210AbfJWSIx (ORCPT ); Wed, 23 Oct 2019 14:08:53 -0400 Received: from mga12.intel.com ([192.55.52.136]:57889 "EHLO mga12.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731908AbfJWSIx (ORCPT ); Wed, 23 Oct 2019 14:08:53 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by fmsmga106.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 23 Oct 2019 11:08:52 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.68,221,1569308400"; d="scan'208";a="209971644" Received: from linux.intel.com ([10.54.29.200]) by fmsmga001.fm.intel.com with ESMTP; 23 Oct 2019 11:08:52 -0700 Received: from [10.249.230.188] (abudanko-mobl.ccr.corp.intel.com [10.249.230.188]) by linux.intel.com (Postfix) with ESMTP id 54F3A580107; Wed, 23 Oct 2019 11:08:49 -0700 (PDT) Subject: Re: [PATCH v2 4/9] perf affinity: Add infrastructure to save/restore affinity To: Andi Kleen 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 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> From: Alexey Budankov Organization: Intel Corp. Message-ID: <346239e4-f156-01bb-4e42-85db289c476b@linux.intel.com> Date: Wed, 23 Oct 2019 21:08:47 +0300 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.9.0 MIME-Version: 1.0 In-Reply-To: <20191023171904.ft735ormkro6tahp@two.firstfloor.org> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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. ~Alexey > > I haven't seen any large enough perf record usage to run > into the IPI problems for record. > > -Andi >