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=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED, USER_AGENT_MUTT 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 1228BC32788 for ; Thu, 11 Oct 2018 14:15:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C79B320841 for ; Thu, 11 Oct 2018 14:15:47 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C79B320841 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.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 S1728632AbeJKVnI (ORCPT ); Thu, 11 Oct 2018 17:43:08 -0400 Received: from mx1.redhat.com ([209.132.183.28]:44516 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726537AbeJKVnI (ORCPT ); Thu, 11 Oct 2018 17:43:08 -0400 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 99177A5D8C; Thu, 11 Oct 2018 14:15:45 +0000 (UTC) Received: from krava (unknown [10.43.17.150]) by smtp.corp.redhat.com (Postfix) with SMTP id E6D739408D; Thu, 11 Oct 2018 14:15:43 +0000 (UTC) Date: Thu, 11 Oct 2018 16:15:43 +0200 From: Jiri Olsa To: Alexey Budankov Cc: Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Alexander Shishkin , Namhyung Kim , Andi Kleen , linux-kernel Subject: Re: [PATCH v12 2/3]: perf record: enable asynchronous trace writing Message-ID: <20181011141543.GF29634@krava> References: <50fed9ff-adc4-d9d6-36bc-b6b27bf58c17@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <50fed9ff-adc4-d9d6-36bc-b6b27bf58c17@linux.intel.com> User-Agent: Mutt/1.10.1 (2018-07-13) X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.26]); Thu, 11 Oct 2018 14:15:45 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 thanks, jirka