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=-14.0 required=3.0 tests=BAYES_00,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 3AD7BC433DB for ; Tue, 29 Dec 2020 05:54:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0B1BC208D5 for ; Tue, 29 Dec 2020 05:54:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726348AbgL2Fy3 (ORCPT ); Tue, 29 Dec 2020 00:54:29 -0500 Received: from mail-qt1-f174.google.com ([209.85.160.174]:36099 "EHLO mail-qt1-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725832AbgL2Fy2 (ORCPT ); Tue, 29 Dec 2020 00:54:28 -0500 Received: by mail-qt1-f174.google.com with SMTP id z20so8367858qtq.3 for ; Mon, 28 Dec 2020 21:54:12 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=gPNfML2ks2KPHAzz+TPLrKUVoqsU6o/9WIH8efYkIsY=; b=U52nAg3+/RL25mHXu1NgbT0ig+v6Hpsx4ITDG8c+ll5oWVE33se39nOP+mu/EsnpQP IF0aBwnL6uF6grIp4HJW8XxqmrLjmdTcFXKuPt/HeLhvrWv0ynQbTE6EYkV3LnR4vubn GVEH6YAw60BwmoJyXm+/d4fl4Mv4pbhVoHUJWyP66XcIylTNUCl/YB9rIZEafirzPdLT OINyuG4kzFRCpFT1P/QafhT7C0vQcSPxgaYCwfqVok/jmeb3XmamJ6GU+x4ixcqHPfMw W+OYkMRbX1pUP+4GhM4uCrY94ejw/HGicIVQRwy+jhPy7BnLZa4+XzwV4sreiQAbBjt6 Hknw== X-Gm-Message-State: AOAM5323Oo1+RqSPSh1/gIGQ37GkqyvIA5XG53M1wQNhYD3x+Ws0m/6c sOUqMygg5cl8HLB1h6RpMkOkM7NLW8v0KWvheHQ= X-Google-Smtp-Source: ABdhPJxziGr0Gy0rSHzv0CRlVa9EDYV1bacoCFtdkD+lg44fmnfyJCY5UlZgEdI5b/yOKuD9P8gpMue5AjZRb3D8sF4= X-Received: by 2002:ac8:5806:: with SMTP id g6mr47211020qtg.292.1609221227277; Mon, 28 Dec 2020 21:53:47 -0800 (PST) MIME-Version: 1.0 References: <20201225222109.364465-1-jolsa@kernel.org> In-Reply-To: <20201225222109.364465-1-jolsa@kernel.org> From: Namhyung Kim Date: Tue, 29 Dec 2020 14:53:36 +0900 Message-ID: Subject: Re: [PATCH] perf tools: Detect when pipe is passed as perf data To: Jiri Olsa Cc: Arnaldo Carvalho de Melo , lkml , Peter Zijlstra , Ingo Molnar , Mark Rutland , Alexander Shishkin , Michael Petlan , Ian Rogers , Stephane Eranian , Alexei Budankov Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Dec 26, 2020 at 7:21 AM Jiri Olsa wrote: > > Currently we allow pipe input/output only through '-' string > being passed to '-o' or '-i' options, like: > > # 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 > --- > 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..767b6c903cf5 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|O_CREAT|O_TRUNC; I don't think we need O_CREAT here (maybe O_TRUNC as well). Thanks, Namhyung > + > + 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; > }