From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1792701869; b=IxQ0SoUa6ROON+iqbNkWVvSH/Tn9qqWCwjm6035Uq6TJkuyQcG+xU5KoyT/N5ei/69Ag 4bvEYMFu8zvyRoEijeU7TLPyhmjqknQDq4ALjg9dBRSLpGaIzgL+MajpOS+NDZqr08aAI btM89W8iHKhQHZu8rI+3j73E5Tz7j0MK7YRbqiOX3+DqirIrqzu+2v7DJmGJ4VugsihuF Hp5sREEUdSSbfcO9aNnSTr0+o4YQq+hHSC1p1mEIS8iV43YgwMmX3AsGwZnFzAsfq2uEB w/P74rKCmq9ZJi1enmW/w7Z+hY77/mckJ94xuvlzTlaawKv9wg/bixUs3NGb3+bfiNA== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1792701869; h=Received:DKIM-Signature:Message-ID:From:Subject:Reply-To:To:Cc: In-Reply-To:References:Content-Type:Content-Transfer-Encoding:Date; bh=eJNYhOERQ4ZI6pBemNFbnK3+hGimxjEr6t6iyYFT1Yc=; b=G3C9w4d0kliQhDcmCnA4wJN0dcNi6SPpU3eOG7fLKcif4pPljDc5csREp8EB9WzgSB42 dtKJ1WlJiwq0n3WhLwGdPqRImFxNwEmj1pG3quIO8LhbrGSirqBzzaa66X3LLWHTA9o8Q 6LtyVd32fee2OF1Wl9aUfanjmmTa8QpcsKuvrlCB1WUG6A+mT66DyhmgS3h0g9nt+lT78 yJedCC1Ob58NtTplFlaNCLg/GJDX6NzwTFQ6grs1dDuvXJCly3HcJVDS9K/uyJ4lim/xn HrFIic6n233WLN+f6EJ/8iaDcXfV5JHQRCDz0wE2/ig2kdemXqPRuUQ/vTLy+3onfyA== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=EV1RsrE1; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 30A31606A32E for ; Thu, 22 Oct 2026 20:44:29 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=EV1RsrE1 Received: by smtp.kernel.org (Postfix) with ESMTPSA id B703E1F01828; Thu, 22 Oct 2026 20:44:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1792701868; bh=eJNYhOERQ4ZI6pBemNFbnK3+hGimxjEr6t6iyYFT1Yc=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=EV1RsrE1//f/PjU0HOVJK49cQN1tOmF2I+lBsLk+/Yalj8BAFSEFzQIj7OkAddJGF ID2zi3EABB7kRlFetmCcuoZ0kISVmD9Nu43qmaSrJ+I8rc6pyjSBc3MvLVlctEjDt+ 68WQMszjvBo69oj/jWkpyVoiGmWg7R7VkBiMKxcj0vlsqLlB1VERJJEl5E3trFIEN9 V2xDLQipGhZ6tWnewytgH5fM0OFlH6gEd7Yk+SdXnGjkT+cG41d/fmMBB+pA2Lu6VE xnO4yjhiBNKpwQ4hQptF4uQBA4aDRn/QgUfMye4TH8T4PTR5XD0lfpmkI46uXKNJdC PJXP5aW9luFVA== Message-ID: From: sashiko-bot@kernel.org Subject: Re: [PATCH v6 10/11] perf bpf-filter: Extend lock_held() to support RCU, Tasks Trace RCU, and SRCU Reply-To: sashiko-reviews@lists.linux.dev To: "Ian Rogers" Cc: linux-perf-users@vger.kernel.org In-Reply-To: <20261022203003.1779152-11-irogers@google.com> References: <20261020205859.1080743-1-irogers@google.com> <20261022203003.1779152-1-irogers@google.com> <20261022203003.1779152-11-irogers@google.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Thu, 22 Oct 2026 20:44:28 +0000 X-Mailing-List: linux-perf-users@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list > Extend the lock_held() BPF sample filter to support RCU, Tasks > Trace RCU, and SRCU locks: >=20 > - 'rcu' (supports both read/shared and write/exclusive modes): > - Read/shared ('lock_held_read(rcu)', 'lock_held(rcu:R)', > 'lock_held(rcu_read_lock)'): directly inspects > current->rcu_read_lock_nesting in perf_sample_filter via CO-RE (on > CONFIG_PREEMPT_RCU kernels), accounting for the baseline > rcu_read_lock() nesting acquired by the perf overflow handler itself > (bpf_overflow_handler() and do_perf_sw_event()) with zero extra > fentry/fexit tracing hooks. > - Write/exclusive ('lock_held_write(rcu)', 'lock_held(rcu:W)'): > attaches fentry/fexit hooks to synchronize_rcu(), > synchronize_rcu_expedited(), synchronize_rcu_tasks(), and > rcu_barrier() to track grace-period and barrier waits. > [ ... ] >=20 > # perf record -a -g -e task-clock --filter 'lock_held(rcu:W)' -- sleep 1 > # perf record -a -g -e cycles --filter 'lock_held(srcu)' -- sleep 1 >=20 > Signed-off-by: Ian Rogers Sashiko has reviewed this patch and found no issues. --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20261022203003.1779= 152-1-irogers@google.com?part=3D10