From patchwork Fri Apr 22 15:05:03 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Namhyung Kim X-Patchwork-Id: 12823645 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8E42FC433EF for ; Fri, 22 Apr 2022 15:05:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1380545AbiDVPIJ (ORCPT ); Fri, 22 Apr 2022 11:08:09 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52056 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1449145AbiDVPIH (ORCPT ); Fri, 22 Apr 2022 11:08:07 -0400 Received: from mail-pl1-x629.google.com (mail-pl1-x629.google.com [IPv6:2607:f8b0:4864:20::629]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 05C88522FC; Fri, 22 Apr 2022 08:05:10 -0700 (PDT) Received: by mail-pl1-x629.google.com with SMTP id c12so11435112plr.6; Fri, 22 Apr 2022 08:05:10 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=sender:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=QtTWLu/07PaOqhse6jPfkw/FT33D7RJcBrLdB+qnolI=; b=k2h5CsfW2cvMeKAGwWp1BgWfxVsP6MJtJPLAM9uctk5G6UJ93AMkx+KlKOvmYY5xha 3c+2OdIiViZcO3bWfEIwhLb9npGUN4t1SQMP96btRm7ch2ebJvzNmS0tU6nIgd2mrD4W LezwROIYiXq3wAwBAczXOVgxj9EZzNjNlbebeLumaqGZ3jPFddMjA/Mg8wlgvfQb6AHA 2mdjqsKETwZwoA1daYhb417PzMKzcdJYYtsD3L0Ate9/LWtZCOwBSOT5dU+iEwTChgVX OisTgM/ZzM/mGZNdEYbG8kgDOkOGiKtbdgw99Sbaky3DNkhPLqCuB8kTShEFjDxuxXLy uETg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:sender:from:to:cc:subject:date:message-id :mime-version:content-transfer-encoding; bh=QtTWLu/07PaOqhse6jPfkw/FT33D7RJcBrLdB+qnolI=; b=HiWqJYcVskWxhHRN1emlt6Itx1cKGM932dMtx2X2hQ1py+j0cwWCOe0Ucm+452WD6C SZ8xaGWTM1rev5xTORPcJG1tnNHsO8FNLdp1+UlY7VF7b6+M6Ip81+WnsAFJYJb2YFsl Runjcj3t2sYCCvWH7CNnduCTkU56XoV6H7qoGEXaKeKpxzD2WarsB1yfvrRQnHfInQ+V Dl7i4LhXidWBVB8GawQmEECQ2yukPVkd696ZPKKyM+jA5YtYBhGp5KzaxXukbqAqM87q dqctu2ym1I/3bgN5FsCOp25r2XfRM/4ogFCG3TYLyNaTjWHL6muMrQsndWPAtq7ezS24 Hf5A== X-Gm-Message-State: AOAM533AZl4bk6SHNq2lzXp7G9qTofOcfvrrguCx/OTxfF46dsTWCPqH ITk1Eg5n720P6mXAj4K57XU= X-Google-Smtp-Source: ABdhPJyG0Bi7wHXakeULUUP8mfqC7vGZ5F3da2juiBy/AM8tA2hacLE7yktHHCjGyKofitzJkCXpqg== X-Received: by 2002:a17:902:8d8e:b0:159:4f6:c4aa with SMTP id v14-20020a1709028d8e00b0015904f6c4aamr4862995plo.115.1650639909417; Fri, 22 Apr 2022 08:05:09 -0700 (PDT) Received: from balhae.hsd1.ca.comcast.net ([2601:647:4f00:3590:5deb:57fb:7322:f9d4]) by smtp.gmail.com with ESMTPSA id s11-20020a6550cb000000b0039daee7ed0fsm2390279pgp.19.2022.04.22.08.05.07 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 22 Apr 2022 08:05:08 -0700 (PDT) Sender: Namhyung Kim From: Namhyung Kim To: Arnaldo Carvalho de Melo , Jiri Olsa Cc: Ingo Molnar , Peter Zijlstra , LKML , Andi Kleen , Ian Rogers , Song Liu , Hao Luo , bpf@vger.kernel.org, linux-perf-users@vger.kernel.org, Blake Jones Subject: [RFC RESEND 0/4] perf record: Implement off-cpu profiling with BPF (v1) Date: Fri, 22 Apr 2022 08:05:03 -0700 Message-Id: <20220422150507.222488-1-namhyung@kernel.org> X-Mailer: git-send-email 2.36.0.rc2.479.g8af0fa9b8e-goog MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org X-Patchwork-State: RFC Hello, (Resending with a quick fix for a missing header.) This is the first version of off-cpu profiling support. Together with (PMU-based) cpu profiling, it can show holistic view of the performance characteristics of your application or system. With BPF, it can aggregate scheduling stats for interested tasks and/or states and convert the data into a form of perf sample records. I chose the bpf-output event which is a software event supposed to be consumed by BPF programs and renamed it as "offcpu-time". So it requires no change on the perf report side except for setting sample types of bpf-output event. Basically it collects userspace callstack for tasks as it's what users want mostly. Maybe we can add support for the kernel stacks but I'm afraid that it'd cause more overhead. So the offcpu-time event will always have callchains regardless of the command line option, and it enables the children mode in perf report by default. It adds --off-cpu option to perf record like below: $ sudo perf record -a --off-cpu -- perf bench sched messaging -l 1000 # Running 'sched/messaging' benchmark: # 20 sender and receiver processes per group # 10 groups == 400 processes run Total time: 1.518 [sec] [ perf record: Woken up 9 times to write data ] [ perf record: Captured and wrote 5.313 MB perf.data (53341 samples) ] Then we can run perf report as usual. The below is just to skip less important parts. $ sudo perf report --stdio --call-graph=no --percent-limit=2 # To display the perf.data header info, please use --header/--header-only options. # # # Total Lost Samples: 0 # # Samples: 52K of event 'cycles' # Event count (approx.): 42522453276 # # Children Self Command Shared Object Symbol # ........ ........ ............... ................ .................................. # 9.58% 9.58% sched-messaging [kernel.vmlinux] [k] audit_filter_rules.constprop.0 8.46% 8.46% sched-messaging [kernel.vmlinux] [k] audit_filter_syscall 4.54% 4.54% sched-messaging [kernel.vmlinux] [k] copy_user_enhanced_fast_string 2.94% 2.94% sched-messaging [kernel.vmlinux] [k] unix_stream_read_generic 2.45% 2.45% sched-messaging [kernel.vmlinux] [k] memcg_slab_free_hook # Samples: 983 of event 'offcpu-time' # Event count (approx.): 684538813464 # # Children Self Command Shared Object Symbol # ........ ........ ............... .................... .......................... # 83.86% 0.00% sched-messaging libc-2.33.so [.] __libc_start_main 83.86% 0.00% sched-messaging perf [.] cmd_bench 83.86% 0.00% sched-messaging perf [.] main 83.86% 0.00% sched-messaging perf [.] run_builtin 83.64% 0.00% sched-messaging perf [.] bench_sched_messaging 41.35% 41.35% sched-messaging libpthread-2.33.so [.] __read 38.88% 38.88% sched-messaging libpthread-2.33.so [.] __write 3.41% 3.41% sched-messaging libc-2.33.so [.] __poll The perf bench sched messaging created 400 processes to send/receive messages through unix sockets. It spent a large portion of cpu cycles for audit filter and read/copy the messages while most of the offcpu-time was in read and write calls. You can get the code from 'perf/offcpu-v1' branch in my tree at git://git.kernel.org/pub/scm/linux/kernel/git/namhyung/linux-perf.git Enjoy! :) Thanks, Namhyung Namhyung Kim (4): perf report: Do not extend sample type of bpf-output event perf record: Enable off-cpu analysis with BPF perf record: Implement basic filtering for off-cpu perf record: Handle argument change in sched_switch tools/perf/Makefile.perf | 1 + tools/perf/builtin-record.c | 21 ++ tools/perf/util/Build | 1 + tools/perf/util/bpf_off_cpu.c | 301 +++++++++++++++++++++++++ tools/perf/util/bpf_skel/off_cpu.bpf.c | 214 ++++++++++++++++++ tools/perf/util/evsel.c | 4 +- 6 files changed, 540 insertions(+), 2 deletions(-) create mode 100644 tools/perf/util/bpf_off_cpu.c create mode 100644 tools/perf/util/bpf_skel/off_cpu.bpf.c base-commit: 41204da4c16071be9090940b18f566832d46becc