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=-6.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED 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 27FC4C677FC for ; Thu, 11 Oct 2018 16:31:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C19F221470 for ; Thu, 11 Oct 2018 16:31:21 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C19F221470 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.intel.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729932AbeJKX7R (ORCPT ); Thu, 11 Oct 2018 19:59:17 -0400 Received: from mga06.intel.com ([134.134.136.31]:45737 "EHLO mga06.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727990AbeJKX7R (ORCPT ); Thu, 11 Oct 2018 19:59:17 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga004.jf.intel.com ([10.7.209.38]) by orsmga104.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 11 Oct 2018 09:31:20 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.54,369,1534834800"; d="scan'208";a="240536414" Received: from linux.intel.com ([10.54.29.200]) by orsmga004.jf.intel.com with ESMTP; 11 Oct 2018 09:31:19 -0700 Received: from [10.252.28.165] (abudanko-mobl.ccr.corp.intel.com [10.252.28.165]) by linux.intel.com (Postfix) with ESMTP id ABD0A580496; Thu, 11 Oct 2018 09:31:16 -0700 (PDT) Subject: Re: [PATCH v12 2/3]: perf record: enable asynchronous trace writing To: Jiri Olsa Cc: Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Alexander Shishkin , Namhyung Kim , Andi Kleen , linux-kernel References: <50fed9ff-adc4-d9d6-36bc-b6b27bf58c17@linux.intel.com> <20181011141543.GF29634@krava> From: Alexey Budankov Organization: Intel Corp. Message-ID: <4d64961d-d3fd-3000-34d9-60be3c4627bf@linux.intel.com> Date: Thu, 11 Oct 2018 19:31:15 +0300 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:52.0) Gecko/20100101 Thunderbird/52.9.1 MIME-Version: 1.0 In-Reply-To: <20181011141543.GF29634@krava> 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 11.10.2018 17:15, Jiri Olsa wrote: > On Tue, Oct 09, 2018 at 11:58:53AM +0300, Alexey Budankov wrote: >> >> Trace file offset is read once before mmaps iterating loop and written >> back after all performance data enqueued for aio writing. Trace file offset >> is incremented linearly after every successful aio write operation. >> >> record__aio_sync() blocks till completion of started AIO operation >> and then proceeds. >> >> record__mmap_read_sync() implements a barrier for all incomplete >> aio write requests. >> >> Signed-off-by: Alexey Budankov >> --- >> Changes in v12: >> - implemented record__aio_get/set_pos(), record__aio_enabled() >> - implemented simple --aio option >> Changes in v11: >> - replacing the both lseek() syscalls in every loop iteration by the only >> two syscalls just before and after the loop at record__mmap_read_evlist() >> and advancing *in-flight* off file pos value at perf_mmap__aio_push() >> Changes in v10: >> - avoided lseek() setting file pos back in case of record__aio_write() failure >> - compacted code selecting between serial and AIO streaming >> - optimized call places of record__mmap_read_sync() >> Changes in v9: >> - enable AIO streaming only when --aio-cblocks option is specified explicitly >> Changes in v8: >> - split AIO completion check into separate record__aio_complete() >> Changes in v6: >> - handled errno == EAGAIN case from aio_write(); >> Changes in v5: >> - data loss metrics decreased from 25% to 2x in trialed configuration; >> - avoided nanosleep() prior calling aio_suspend(); >> - switched to per cpu multi record__aio_sync() aio >> - record_mmap_read_sync() now does global barrier just before >> switching trace file or collection stop; >> - resolved livelock on perf record -e intel_pt// -- dd if=/dev/zero of=/dev/null count=100000 >> Changes in v4: >> - converted void *bf to struct perf_mmap *md in signatures >> - written comment in perf_mmap__push() just before perf_mmap__get(); >> - written comment in record__mmap_read_sync() on possible restarting >> of aio_write() operation and releasing perf_mmap object after all; >> - added perf_mmap__put() for the cases of failed aio_write(); >> Changes in v3: >> - written comments about nanosleep(0.5ms) call prior aio_suspend() >> to cope with intrusiveness of its implementation in glibc; >> - written comments about rationale behind coping profiling data >> into mmap->data buffer; >> --- >> tools/perf/Documentation/perf-record.txt | 5 + >> tools/perf/builtin-record.c | 220 ++++++++++++++++++++++++++++++- >> tools/perf/perf.h | 1 + >> tools/perf/util/evlist.c | 6 +- >> tools/perf/util/evlist.h | 2 +- >> tools/perf/util/mmap.c | 86 +++++++++++- >> tools/perf/util/mmap.h | 5 + >> 7 files changed, 316 insertions(+), 9 deletions(-) >> >> diff --git a/tools/perf/Documentation/perf-record.txt b/tools/perf/Documentation/perf-record.txt >> index 246dee081efd..5cedb3e75434 100644 >> --- a/tools/perf/Documentation/perf-record.txt >> +++ b/tools/perf/Documentation/perf-record.txt >> @@ -435,6 +435,11 @@ Specify vmlinux path which has debuginfo. >> --buildid-all:: >> Record build-id of all DSOs regardless whether it's actually hit or not. >> >> +--aio:: >> +Enable asynchronous (Posix AIO) trace writing mode. > > nit, there's an extra whitespace at the end of above line, > making the 'git am' to not apply your patch Corrected trailing whitespace. Thanks! - Alexey > > thanks, > jirka >