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=-16.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 093D3C433E6 for ; Mon, 11 Jan 2021 10:58:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C599F2222D for ; Mon, 11 Jan 2021 10:58:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729596AbhAKK6R (ORCPT ); Mon, 11 Jan 2021 05:58:17 -0500 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:56242 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729372AbhAKK6Q (ORCPT ); Mon, 11 Jan 2021 05:58:16 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1610362609; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=e+Vq/8bmKni7bGYalB55TS1xHbS37RSImPWuJfrT6hY=; b=Ok+WBJXqvVPY6NCW71SUuwgNsGv9UB5h8d/94a28qOa6UrmZKWcpmDdiAlNRqtkvITsk8k Tyb/iCd24oKjotplk0h6saoCa5udG/isz3eYt4yUaOodHp8vbNebqc35/XXKEZTxgU2FT2 Q2g6qrNcBD+mnrWmkHAp1YylKwxJx2g= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-469-97Y9n1KrO7iVSz3KMHdvBg-1; Mon, 11 Jan 2021 05:56:45 -0500 X-MC-Unique: 97Y9n1KrO7iVSz3KMHdvBg-1 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 mimecast-mx01.redhat.com (Postfix) with ESMTPS id 68DC88049C2; Mon, 11 Jan 2021 10:56:43 +0000 (UTC) Received: from krava (unknown [10.40.192.185]) by smtp.corp.redhat.com (Postfix) with SMTP id 0D07F19746; Mon, 11 Jan 2021 10:56:39 +0000 (UTC) Date: Mon, 11 Jan 2021 11:56:38 +0100 From: Jiri Olsa To: Stephane Eranian Cc: Jiri Olsa , Arnaldo Carvalho de Melo , lkml , Peter Zijlstra , Ingo Molnar , Mark Rutland , Namhyung Kim , Alexander Shishkin , Michael Petlan , Ian Rogers , Alexei Budankov Subject: Re: [PATCHv2] perf tools: Detect when pipe is passed as perf data Message-ID: <20210111105638.GA1210240@krava> References: <20201230110935.582332-1-jolsa@kernel.org> <20210106094934.GA972880@krava> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, Jan 10, 2021 at 11:13:18PM -0800, Stephane Eranian wrote: > On Wed, Jan 6, 2021 at 1:49 AM Jiri Olsa wrote: > > > > On Tue, Jan 05, 2021 at 05:33:38PM -0800, Stephane Eranian wrote: > > > Hi, > > > > > > On Wed, Dec 30, 2020 at 3:09 AM Jiri Olsa wrote: > > > > > > > > Currently we allow pipe input/output only through '-' string > > > > being passed to '-o' or '-i' options, like: > > > > > > > It seems to me it would be useful to auto-detect that the perf.data > > > file is in pipe vs. file mode format. > > > Your patch detects the type of the file which is something different > > > from the format of its content. > > > > hi, > > it goes together with the format, once the output file > > is pipe, the format is pipe as well > > > What I was saying is if I do: > $ perf record -o - -a sleep 10 > perf.data > $ perf report -i perf.data > it should autodetect it is a pipe mode file. > Does it do that today? yes, your record stores pipe mode data to perf.data file, and report detects pipe mode data even in normal file, so we're fine here jirka > > > jirka > > > > > Thanks. > > > > > > > # mkfifo perf.pipe > > > > # perf record --no-buffering -e 'sched:sched_switch' -o - > perf.pipe & > > > > [1] 354406 > > > > # cat perf.pipe | ./perf --no-pager script -i - | head -3 > > > > perf 354406 [000] 168190.164921: sched:sched_switch: perf:354406.. > > > > migration/0 12 [000] 168190.164928: sched:sched_switch: migration/0:.. > > > > perf 354406 [001] 168190.164981: sched:sched_switch: perf:354406.. > > > > ... > > > > > > > > This patch detects if given path is pipe and set the perf data > > > > object accordingly, so it's possible now to do above with: > > > > > > > > # mkfifo perf.pipe > > > > # perf record --no-buffering -e 'sched:sched_switch' -o perf.pipe & > > > > [1] 360188 > > > > # perf --no-pager script -i ./perf.pipe | head -3 > > > > perf 354442 [000] 168275.464895: sched:sched_switch: perf:354442.. > > > > migration/0 12 [000] 168275.464902: sched:sched_switch: migration/0:.. > > > > perf 354442 [001] 168275.464953: sched:sched_switch: perf:354442.. > > > > > > > > It's of course possible to combine any of above ways. > > > > > > > > Signed-off-by: Jiri Olsa > > > > --- > > > > v2: > > > > - removed O_CREAT|O_TRUNC flags from pipe's write end > > > > > > > > tools/perf/util/data.c | 27 +++++++++++++++++++++------ > > > > 1 file changed, 21 insertions(+), 6 deletions(-) > > > > > > > > diff --git a/tools/perf/util/data.c b/tools/perf/util/data.c > > > > index f29af4fc3d09..4dfa9e0f2fec 100644 > > > > --- a/tools/perf/util/data.c > > > > +++ b/tools/perf/util/data.c > > > > @@ -159,7 +159,7 @@ int perf_data__update_dir(struct perf_data *data) > > > > return 0; > > > > } > > > > > > > > -static bool check_pipe(struct perf_data *data) > > > > +static int check_pipe(struct perf_data *data) > > > > { > > > > struct stat st; > > > > bool is_pipe = false; > > > > @@ -172,6 +172,15 @@ static bool check_pipe(struct perf_data *data) > > > > } else { > > > > if (!strcmp(data->path, "-")) > > > > is_pipe = true; > > > > + else if (!stat(data->path, &st) && S_ISFIFO(st.st_mode)) { > > > > + int flags = perf_data__is_read(data) ? > > > > + O_RDONLY : O_WRONLY; > > > > + > > > > + fd = open(data->path, flags); > > > > + if (fd < 0) > > > > + return -EINVAL; > > > > + is_pipe = true; > > > > + } > > > > } > > > > > > > > if (is_pipe) { > > > > @@ -190,7 +199,8 @@ static bool check_pipe(struct perf_data *data) > > > > } > > > > } > > > > > > > > - return data->is_pipe = is_pipe; > > > > + data->is_pipe = is_pipe; > > > > + return 0; > > > > } > > > > > > > > static int check_backup(struct perf_data *data) > > > > @@ -344,8 +354,11 @@ static int open_dir(struct perf_data *data) > > > > > > > > int perf_data__open(struct perf_data *data) > > > > { > > > > - if (check_pipe(data)) > > > > - return 0; > > > > + int err; > > > > + > > > > + err = check_pipe(data); > > > > + if (err || data->is_pipe) > > > > + return err; > > > > > > > > /* currently it allows stdio for pipe only */ > > > > data->use_stdio = false; > > > > @@ -410,8 +423,10 @@ int perf_data__switch(struct perf_data *data, > > > > { > > > > int ret; > > > > > > > > - if (check_pipe(data)) > > > > - return -EINVAL; > > > > + ret = check_pipe(data); > > > > + if (ret || data->is_pipe) > > > > + return ret; > > > > + > > > > if (perf_data__is_read(data)) > > > > return -EINVAL; > > > > > > > > -- > > > > 2.26.2 > > > > > > > > > >