From patchwork Wed Feb 12 22:24:51 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: 13972540 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 9125C21019E for ; Wed, 12 Feb 2025 22:29:04 +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=1739399346; cv=none; b=Ui+t1KVkHX7bQH96r7twu8QLUq+9b6GK7N1uZmrbCSppVm9tM9EAHFW31Uw2+b1r1lsQ7lefRtnKjUxTFPm61po6z62+2FH8ynbxHK/pXkqHlDBURsseGXmXOtJJ8ReDjaA032YJ2sHdiM6k3RXH4H1L89H9K6Iqc8DaJfhAgoM= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1739399346; c=relaxed/simple; bh=vrXQBzZLHyWqS64CTDiirsBQO9JgZrbt74ofDZ59COY=; h=Date:Mime-Version:Message-ID:Subject:From:To:Cc:Content-Type; b=BmDdgqZROOS0U5gycDqMpNLcT96NeZ/kzmBqANJ9U/eVUc3fEoeM35VHEOrPlOJfOE7wmpsQ+w2PxA57E6eDNGhp0fhbk86hwOlpGBSqGbHSOZYrC3RstT9DDLydyTKYouAm8D4KnFdUvI1Pzy13V6NmGH1LVfmk53DP/2o17hc= 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=luCO68Ut; 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="luCO68Ut" Received: by mail-pj1-f74.google.com with SMTP id 98e67ed59e1d1-2fc0bc05b36so734645a91.3 for ; Wed, 12 Feb 2025 14:29:04 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1739399344; x=1740004144; darn=vger.kernel.org; h=cc:to:from:subject:message-id:mime-version:date:from:to:cc:subject :date:message-id:reply-to; bh=Ops18fMc+NWzGSM8vJwyhsQmNBMs6kMxdvy3bOSxpxk=; b=luCO68UtekvwfoCXDjQOwav+xU0DGiNE3MoO5frc8qL6hstfKyg7p4IvrBpHbIqBec uvhIlmIxYhaag+qEKwMzhqYRWjV+oLMCznlCHqVQKxqc2h11imilYF6qdCoGOgLKDvge gWhRyLr4na+XPldHXYRbT1VzL7j8vrldt94Ro8qEyRGJvtb95CM+ETS3nshAPyLvHnVJ q8jp4J7DJw4waoT+gH0RrsueKZVKE0UiFiEJliV9dV+H7P+rP9hF9AyL6nmwJ29y46Lz CfY6STH8A21tdBS2YtvE5miTlveL/9T1hISUIGwP2gKrMnz00ARui6jwKWrqviOWvRaa L/Og== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1739399344; x=1740004144; h=cc:to:from:subject:message-id:mime-version:date:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=Ops18fMc+NWzGSM8vJwyhsQmNBMs6kMxdvy3bOSxpxk=; b=ONHH6JGib/SmnH8HgQAoroOkqH/wXEX8HDDaxkY63WRIpXcOlKZO+bKD6etWtA3+fF 5VwLhmW4qPczllydrMBUPVukfMBeuAz1fOcaMCgrxBRo8foMF74XHVpH7ZqTcVHaOFnW y6/2wAAe4FYVVGgIkL9i4nGmEBjDvLPXKynLkXMfnPN3fPRLTnl0hLKTar0LcGhQCqtr 1XvnqIXJqE6Rsst3/QraATlJabd3ttjG8L6zKA1LIV3aFx9FdSYJQv6ufWKlMLIrTufv M0mpL3qjz3u12q4HLkGLmae2K7rzA1EIQitTTQxbFZqyE1VCsBPmwsix21iGtADvnTz7 pw+A== X-Forwarded-Encrypted: i=1; AJvYcCXpqSSZ8O/yIAO0j3/im51uFDhSVb0M+IcfdBGEuz92uY1s4o4fzgPsCcNJLFfblBIioCE=@vger.kernel.org X-Gm-Message-State: AOJu0YxGHdrLMgu7CjK18h3bifXfbbwh9BOBoX0zSY7rFkJcU8Y6fieU 9wUDdwgDH4nTEmoYb4KiRfCCfZ09xVhHtL3bRdAka57q7cihw2sZOGG64mRgUADYI0/TD+8FpCT r+Q== X-Google-Smtp-Source: AGHT+IF3ZXoEyE4KPjh18j6I0r1uGq7qRrUlWVGa2SDtefltt/F2NlHzYljpGmfH3tjOGVfJWZFHSk9U+0o= X-Received: from pjbpl10.prod.google.com ([2002:a17:90b:268a:b0:2fc:11a0:c53f]) (user=ctshao job=prod-delivery.src-stubby-dispatcher) by 2002:a17:90a:e183:b0:2ee:d63f:d71 with SMTP id 98e67ed59e1d1-2fbf5bec92bmr8716045a91.14.1739399343897; Wed, 12 Feb 2025 14:29:03 -0800 (PST) Date: Wed, 12 Feb 2025 14:24:51 -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 2.48.1.502.g6dc24dfdaf-goog Message-ID: <20250212222859.2086080-1-ctshao@google.com> Subject: [PATCH v5 0/5] 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, 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 ... v5: 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 (5): 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 perf lock: Update documentation for -o option in contention mode tools/perf/builtin-lock.c | 59 +++- tools/perf/util/bpf_lock_contention.c | 68 ++++- .../perf/util/bpf_skel/lock_contention.bpf.c | 251 +++++++++++++++++- tools/perf/util/bpf_skel/lock_data.h | 7 + tools/perf/util/lock-contention.h | 7 + 5 files changed, 367 insertions(+), 25 deletions(-) --- 2.48.1.502.g6dc24dfdaf-goog