From patchwork Thu Feb 27 00:28:52 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chun-Tse Shao X-Patchwork-Id: 13993359 Received: from mail-pj1-f74.google.com (mail-pj1-f74.google.com [209.85.216.74]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id C4D7A38DD3 for ; Thu, 27 Feb 2025 00:34:12 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.216.74 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740616455; cv=none; b=elO3NQwjqpeQPgs2gb7bSr0ZlG0P+k7Q54ZvvDnimHcGXdYJebL/BTDGsG+m7U5auoWB2pZUCUvbPjCUGyIu9pAWO2SH3AtrcdK09kVb1X2ElNn+NjABhwnjhqW58Un4GifyEcXDO79l2/tkpb99Gy8wXCFIxIBbAK9cezzHMwU= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740616455; c=relaxed/simple; bh=nU3y6YFsyIHN1dmjBlB/Wl3ngK6IdRrA1IoHzKQzagI=; h=Date:Mime-Version:Message-ID:Subject:From:To:Cc:Content-Type; b=Tmcw/caarZv7UiL26rQPwWw4V//FLasIINYqanTX3WtyohnQWGyZDcWG8oLS+U7FJegaFZh6D/FWb5ZXJEcTwwnKRe1jrQXioTpSKoy/QYAaWmmWHpaCK0m2ADX88vN99ZbfbsZJ9ZDwue6PrBuMEwRoiLRMbkDlxgse1Xn9Szo= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--ctshao.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=tJGNsDd4; arc=none smtp.client-ip=209.85.216.74 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--ctshao.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="tJGNsDd4" Received: by mail-pj1-f74.google.com with SMTP id 98e67ed59e1d1-2fe86c01f5cso849776a91.1 for ; Wed, 26 Feb 2025 16:34:12 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1740616452; x=1741221252; darn=vger.kernel.org; h=cc:to:from:subject:message-id:mime-version:date:from:to:cc:subject :date:message-id:reply-to; bh=jUI6/1gyibvrTbWNNqX1qF+Ovy2PNmTRwmWu1BHDQsE=; b=tJGNsDd4UQqaOUBjs7F3CpZelhQDaj3fW7BWfmUdKXHADURkk3RVKFwl+KUqmmovty JdOjuHilYkHbff82Tbc7F+gRuL4cVBh/D7pc7yhutFqsp42LsLT3rDEyUhDxwimKBMYy KtvqNMRup+Ycmqot92kIKlr5u9Bp932y9ox3jZ4K9GnXjX+EG0JZHPtf47ZK2EruTy6G E/9KSgECtY6ZLih+mypFMSb2ckt5Z1XgQbbNIY2iLTezvUvhI2UBhr7H2lgWsdjLG+XF MyrMQctISgrDGebABO1FopAdPgtNRAXDswi/gcXIg8Sh9Oz/XYahPFu31LqIDF6rA72L 8nRA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1740616452; x=1741221252; h=cc:to:from:subject:message-id:mime-version:date:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=jUI6/1gyibvrTbWNNqX1qF+Ovy2PNmTRwmWu1BHDQsE=; b=IrSBXj1LXWTN+idQG4QVHSJtBMvs6+af5SDOMkLcCImjsYpyJXXtQv3MTXohlDfX0J F+AJkP1DgXng/kQnhWxXtouh4Am1zTZ29uHwHDFK0PulXL4PNRHeEoNhLap3YbA3TcWO 2aX/9D8ilcthcxC+Zeao6QD76I3AwX1bQFewa+W3RAZKIAFuJtyxmaibj70lFbyVOOoQ dSD8yVOduMZDsIRW0m29nOkzjPesB7sS+JZhdd9Mz1qoSs0rTgwHoK9CtEsoRg5g+Y36 pY1abcEqbUDPo/ArJkDPN5lgwlEnRCfYr+X6uLZgxt0iv98rykT8prUliIIEGClwIENh JyvA== X-Forwarded-Encrypted: i=1; AJvYcCXIQc+WP7+irP5pT+J6+mnyNBsTnIBLuGMMLGWDnXoUT1jizO6WdFLO/Ts/2zTJqJftQA0=@vger.kernel.org X-Gm-Message-State: AOJu0YwlOXQgTV7PZTFHSqwnA0EDUq/TnLtinkcztQdlRCkQefMnPn9G CiAtd0RadvvTsrwFk53ncgp2lIShJDEGgWGmCKB0LHsUtO6jsL0oO6hVcS9U8s1SvKZabvUjYB2 +uw== X-Google-Smtp-Source: AGHT+IHDAQK/BsvI6mzuilkbqC4HRSy4qcc5tMuIfa3jBRAGH5Fcp4vFyNJuSfyPfVtwa/ebYbFuN9eV1F4= X-Received: from pfbf4.prod.google.com ([2002:a05:6a00:ad84:b0:730:94db:d304]) (user=ctshao job=prod-delivery.src-stubby-dispatcher) by 2002:a05:6a20:a103:b0:1ee:de1d:5abc with SMTP id adf61e73a8af0-1f0fc78bfe1mr13706786637.33.1740616451981; Wed, 26 Feb 2025 16:34:11 -0800 (PST) Date: Wed, 26 Feb 2025 16:28:52 -0800 Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 X-Mailer: git-send-email 2.48.1.658.g4767266eb4-goog Message-ID: <20250227003359.732948-1-ctshao@google.com> Subject: [PATCH v8 0/4] Tracing contention lock owner call stack From: Chun-Tse Shao To: linux-kernel@vger.kernel.org Cc: Chun-Tse Shao , peterz@infradead.org, mingo@redhat.com, acme@kernel.org, namhyung@kernel.org, mark.rutland@arm.com, alexander.shishkin@linux.intel.com, jolsa@kernel.org, irogers@google.com, adrian.hunter@intel.com, kan.liang@linux.intel.com, nick.forrington@arm.com, linux-perf-users@vger.kernel.org, bpf@vger.kernel.org For perf lock contention, the current owner tracking (-o option) only works with per-thread mode (-t option). Enabling call stack mode for owner can be useful for diagnosing why a system running slow in lock contention. Example output: $ sudo ~/linux/tools/perf/perf lock con -abvo -Y mutex -E16 perf bench sched pipe ... contended total wait max wait avg wait type caller 171 1.55 ms 20.26 us 9.06 us mutex pipe_read+0x57 0xffffffffac6318e7 pipe_read+0x57 0xffffffffac623862 vfs_read+0x332 0xffffffffac62434b ksys_read+0xbb 0xfffffffface604b2 do_syscall_64+0x82 0xffffffffad00012f entry_SYSCALL_64_after_hwframe+0x76 36 193.71 us 15.27 us 5.38 us mutex pipe_write+0x50 0xffffffffac631ee0 pipe_write+0x50 0xffffffffac6241db vfs_write+0x3bb 0xffffffffac6244ab ksys_write+0xbb 0xfffffffface604b2 do_syscall_64+0x82 0xffffffffad00012f entry_SYSCALL_64_after_hwframe+0x76 4 51.22 us 16.47 us 12.80 us mutex do_epoll_wait+0x24d 0xffffffffac691f0d do_epoll_wait+0x24d 0xffffffffac69249b do_epoll_pwait.part.0+0xb 0xffffffffac693ba5 __x64_sys_epoll_pwait+0x95 0xfffffffface604b2 do_syscall_64+0x82 0xffffffffad00012f entry_SYSCALL_64_after_hwframe+0x76 2 20.88 us 11.95 us 10.44 us mutex do_epoll_wait+0x24d 0xffffffffac691f0d do_epoll_wait+0x24d 0xffffffffac693943 __x64_sys_epoll_wait+0x73 0xfffffffface604b2 do_syscall_64+0x82 0xffffffffad00012f entry_SYSCALL_64_after_hwframe+0x76 1 7.33 us 7.33 us 7.33 us mutex do_epoll_ctl+0x6c1 0xffffffffac692e01 do_epoll_ctl+0x6c1 0xffffffffac6937e0 __x64_sys_epoll_ctl+0x70 0xfffffffface604b2 do_syscall_64+0x82 0xffffffffad00012f entry_SYSCALL_64_after_hwframe+0x76 1 6.64 us 6.64 us 6.64 us mutex do_epoll_ctl+0x3d4 0xffffffffac692b14 do_epoll_ctl+0x3d4 0xffffffffac6937e0 __x64_sys_epoll_ctl+0x70 0xfffffffface604b2 do_syscall_64+0x82 0xffffffffad00012f entry_SYSCALL_64_after_hwframe+0x76 === owner stack trace === 3 31.24 us 15.27 us 10.41 us mutex pipe_read+0x348 0xffffffffac631bd8 pipe_read+0x348 0xffffffffac623862 vfs_read+0x332 0xffffffffac62434b ksys_read+0xbb 0xfffffffface604b2 do_syscall_64+0x82 0xffffffffad00012f entry_SYSCALL_64_after_hwframe+0x76 ... v8: Fix compilation error found by Athira Rajeev and Namhyung Kim. v7: lore.kernel.org/20250224184742.4144931-1-ctshao@google.com Remove duplicate contention records. v6: lore.kernel.org/20250219214400.3317548-1-ctshao@google.com Free allocated memory in error patch. Add description in man page. v5: lore.kernel.org/20250212222859.2086080-1-ctshao@google.com Move duplicated code into function. Remove code to retrieve undesired callstack at the end of `contention_end()`. Other minor fix based on Namhyung's review. v4: lore.kernel.org/20250130052510.860318-1-ctshao@google.com Use `__sync_fetch_and_add()` to generate owner stackid automatically. Use `__sync_fetch_and_add(..., -1)` to workaround compiler error from `__sync_fetch_and_sub()` Remove unnecessary include headers. Dedicate on C-style comment. Other minor fix based on Namhyung's review. v3: lore.kernel.org/20250129001905.619859-1-ctshao@google.com Rename/shorten multiple variables. Implement owner stackid. Add description for lock function return code in `contention_end()`. Other minor fix based on Namhyung's review. v2: lore.kernel.org/20250113052220.2105645-1-ctshao@google.com Fix logic deficit in v1 patch 2/4. v1: lore.kernel.org/20250110051346.1507178-1-ctshao@google.com Chun-Tse Shao (4): perf lock: Add bpf maps for owner stack tracing perf lock: Retrieve owner callstack in bpf program perf lock: Make rb_tree helper functions generic perf lock: Report owner stack in usermode tools/perf/Documentation/perf-lock.txt | 5 +- tools/perf/builtin-lock.c | 56 +++- tools/perf/util/bpf_lock_contention.c | 85 +++++- .../perf/util/bpf_skel/lock_contention.bpf.c | 245 +++++++++++++++++- tools/perf/util/bpf_skel/lock_data.h | 7 + tools/perf/util/lock-contention.h | 7 + 6 files changed, 372 insertions(+), 33 deletions(-) Tested-by: Athira Rajeev --- 2.48.1.658.g4767266eb4-goog