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 86F9ACA9EAF for ; Thu, 24 Oct 2019 08:46:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5EA652166E for ; Thu, 24 Oct 2019 08:46:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2438337AbfJXIqP (ORCPT ); Thu, 24 Oct 2019 04:46:15 -0400 Received: from mga06.intel.com ([134.134.136.31]:38749 "EHLO mga06.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730319AbfJXIqP (ORCPT ); Thu, 24 Oct 2019 04:46:15 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by orsmga104.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 24 Oct 2019 01:46:14 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.68,224,1569308400"; d="scan'208";a="398340229" Received: from linux.intel.com ([10.54.29.200]) by fmsmga005.fm.intel.com with ESMTP; 24 Oct 2019 01:46:13 -0700 Received: from [10.125.252.242] (abudanko-mobl.ccr.corp.intel.com [10.125.252.242]) by linux.intel.com (Postfix) with ESMTP id 22FFA580205; Thu, 24 Oct 2019 01:46:10 -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> <346239e4-f156-01bb-4e42-85db289c476b@linux.intel.com> <20191023223704.GI4660@tassilo.jf.intel.com> From: Alexey Budankov Organization: Intel Corp. Message-ID: <6e90cef4-3eba-71aa-2a93-ea8182d47e58@linux.intel.com> Date: Thu, 24 Oct 2019 11:46:10 +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: <20191023223704.GI4660@tassilo.jf.intel.com> 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 24.10.2019 1:37, Andi Kleen wrote: > 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. Ok, I see. > > Everything else you can use normal Linux bitmap functions, > or call the sys call directly. Thanks, Alexey > > -Andi >