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=-6.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,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 2ED63C47254 for ; Mon, 4 May 2020 22:57:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0E1DA206EB for ; Mon, 4 May 2020 22:57:21 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="EiPlFM++" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728197AbgEDW5U (ORCPT ); Mon, 4 May 2020 18:57:20 -0400 Received: from us-smtp-delivery-1.mimecast.com ([207.211.31.120]:38514 "EHLO us-smtp-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1728118AbgEDW5T (ORCPT ); Mon, 4 May 2020 18:57:19 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1588633037; 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=GkjR4idjNOUSc/GgoWxAHk5uuwUM084U0aZLz6e4Oxw=; b=EiPlFM++ErtpEt07JYommneai5Zb5WrZ8soKOn1EEx86Qb6zaH4YIkAWJP/1/da8lMg7HN P9Rg4PORnIij+tq1UTgL4DkfkX0vfGW4lR4aGN5DoAVnE5TF7gqT5FyH+MesS3BCXQu1xn h8AXXmkK+xuz4pY3dKEpLDEhEmaAdsE= 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-297-azVAEaE4NxidvXOzULQWKw-1; Mon, 04 May 2020 18:57:13 -0400 X-MC-Unique: azVAEaE4NxidvXOzULQWKw-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 189558014C0; Mon, 4 May 2020 22:57:12 +0000 (UTC) Received: from krava (unknown [10.40.192.32]) by smtp.corp.redhat.com (Postfix) with ESMTPS id B423E2C2D3; Mon, 4 May 2020 22:57:09 +0000 (UTC) Date: Tue, 5 May 2020 00:57:07 +0200 From: Jiri Olsa To: Jiri Olsa Cc: Arnaldo Carvalho de Melo , Ian Rogers , lkml , Ingo Molnar , Namhyung Kim , Alexander Shishkin , Peter Zijlstra , Michael Petlan Subject: Re: [PATCH] perf session: Try to read pipe data from file Message-ID: <20200504225325.GE1916255@krava> References: <20200501113448.1809037-1-jolsa@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200501113448.1809037-1-jolsa@kernel.org> X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, May 01, 2020 at 01:34:47PM +0200, Jiri Olsa wrote: > From: Jiri Olsa > > Ian came with the idea of having support to read the pipe > data also from file [1]. Currently pipe mode files fails > like: > > $ perf record -o - sleep 1 > /tmp/perf.pipe.data > $ perf report -i /tmp/perf.pipe.data > incompatible file format (rerun with -v to learn more) > > This patch adds the support to do that by trying the pipe > header first, and if its successfully detected, switching > the perf data to pipe mode. > > [1] https://lore.kernel.org/lkml/20200409185744.255881-1-irogers@google.com/ > Original-patch-by: Ian Rogers > Signed-off-by: Jiri Olsa actualy.. I found another issue while trying this on tracepoints: # ./perf record -g -e 'raw_syscalls:sys_enter' -o - true > data [ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 0.000 MB - ] # ./perf script -i ./data perf_event__process_tracing_data: tracing data size mismatch0x1034 [0xc]: failed to process type: 66 it's because some of the pipe synthesize code calls lseek, which fails on pipe, but succeeds on normal file (with pipe data) patch below fixes that for me, but I wonder there are other leftovers like this.. I'll check on post it all together jirka --- diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c index 8ca709f938b8..33e299674121 100644 --- a/tools/perf/util/header.c +++ b/tools/perf/util/header.c @@ -3955,13 +3955,8 @@ int perf_event__process_tracing_data(struct perf_session *session, { ssize_t size_read, padding, size = event->tracing_data.size; int fd = perf_data__fd(session->data); - off_t offset = lseek(fd, 0, SEEK_CUR); char buf[BUFSIZ]; - /* setup for reading amidst mmap */ - lseek(fd, offset + sizeof(struct perf_record_header_tracing_data), - SEEK_SET); - size_read = trace_report(fd, &session->tevent, session->repipe); padding = PERF_ALIGN(size_read, sizeof(u64)) - size_read; diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c index c11d89e0ee55..b75df19feaf1 100644 --- a/tools/perf/util/session.c +++ b/tools/perf/util/session.c @@ -1543,7 +1543,8 @@ static s64 perf_session__process_user_event(struct perf_session *session, return 0; case PERF_RECORD_HEADER_TRACING_DATA: /* setup for reading amidst mmap */ - lseek(fd, file_offset, SEEK_SET); + if (!perf_data__is_pipe(session->data)) + lseek(fd, file_offset, SEEK_SET); return tool->tracing_data(session, event); case PERF_RECORD_HEADER_BUILD_ID: return tool->build_id(session, event);