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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,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 8124CC433F4 for ; Tue, 28 Aug 2018 09:39:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3B577208AC for ; Tue, 28 Aug 2018 09:39:45 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3B577208AC 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 S1727471AbeH1Nab (ORCPT ); Tue, 28 Aug 2018 09:30:31 -0400 Received: from mga01.intel.com ([192.55.52.88]:55063 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727169AbeH1Nab (ORCPT ); Tue, 28 Aug 2018 09:30:31 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga005.jf.intel.com ([10.7.209.41]) by fmsmga101.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 28 Aug 2018 02:39:42 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.53,298,1531810800"; d="scan'208";a="252512584" Received: from linux.intel.com ([10.54.29.200]) by orsmga005.jf.intel.com with ESMTP; 28 Aug 2018 02:39:35 -0700 Received: from [10.125.252.157] (abudanko-mobl.ccr.corp.intel.com [10.125.252.157]) by linux.intel.com (Postfix) with ESMTP id 071195803DA; Tue, 28 Aug 2018 02:39:33 -0700 (PDT) Subject: Re: [PATCH v3 2/2]: perf record: enable asynchronous trace writing To: Jiri Olsa Cc: Ingo Molnar , Peter Zijlstra , Arnaldo Carvalho de Melo , Alexander Shishkin , Namhyung Kim , Andi Kleen , linux-kernel References: <6f83f9cd-263e-b073-487f-4c7570105a7d@linux.intel.com> <20180828085022.GE23727@krava> From: Alexey Budankov Organization: Intel Corp. Message-ID: Date: Tue, 28 Aug 2018 12:39:33 +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: <20180828085022.GE23727@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 Hi, On 28.08.2018 11:50, Jiri Olsa wrote: > On Mon, Aug 27, 2018 at 09:16:55PM +0300, Alexey Budankov wrote: >> >> Trace file offset are linearly calculated by perf_mmap__push() code >> for the next possible write operation, but file position is updated by >> the kernel only in the second lseek() syscall after the loop. >> The first lseek() syscall reads that file position for >> the next loop iterations. >> >> record__mmap_read_sync implements sort of a barrier between spilling >> ready profiling data to disk. >> >> Signed-off-by: Alexey Budankov >> --- >> 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/builtin-record.c | 125 +++++++++++++++++++++++++++++++++++++++++--- >> tools/perf/util/mmap.c | 36 ++++++++----- >> tools/perf/util/mmap.h | 2 +- >> 3 files changed, 143 insertions(+), 20 deletions(-) >> >> diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c >> index 22ebeb92ac51..4ac61399a09a 100644 >> --- a/tools/perf/builtin-record.c >> +++ b/tools/perf/builtin-record.c >> @@ -53,6 +53,7 @@ >> #include >> #include >> #include >> +#include >> >> struct switch_output { >> bool enabled; >> @@ -121,6 +122,23 @@ static int record__write(struct record *rec, void *bf, size_t size) >> return 0; >> } >> >> +static int record__aio_write(int trace_fd, struct aiocb *cblock, >> + void *buf, size_t size, off_t off) >> +{ >> + cblock->aio_fildes = trace_fd; >> + cblock->aio_buf = buf; >> + cblock->aio_nbytes = size; >> + cblock->aio_offset = off; >> + cblock->aio_sigevent.sigev_notify = SIGEV_NONE; >> + >> + if (aio_write(cblock) == -1) { >> + pr_err("failed to queue perf data, error: %m\n"); >> + return -1; >> + } >> + >> + return 0; >> +} >> + >> static int process_synthesized_event(struct perf_tool *tool, >> union perf_event *event, >> struct perf_sample *sample __maybe_unused, >> @@ -130,12 +148,14 @@ static int process_synthesized_event(struct perf_tool *tool, >> return record__write(rec, event, event->header.size); >> } >> >> -static int record__pushfn(void *to, void *bf, size_t size) >> +static int record__pushfn(void *to, void *bf, size_t size, off_t off) >> { >> struct record *rec = to; >> + struct perf_mmap *map = bf; > > the argument needs to change for record__pushfn, > now with your changes, it's no longer 'void *bf', > but 'struct perf_mmap *map' Ok. Included into [PATCH v4 2/2]. > > also I'm little confused why we have '*to' and cast > it back to 'struct record', but so be it ;-) Supported. :) > > thanks, > jirka >