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=1792538969; b=r0V+fKTa3iIhk0N1EKm/iqVRAm6mfjLgtk16lX8w+inw3l6rcOLkqtUfK6Mb1dtUZnu2 GVQbqJz5zhIisIOL0me+fbw4kVlzCkHifLNAXESsaNG/XveroiyP9cACUrKfxOSBn2w83 75oTlnPs2pQ7BFEmlpEmRZfYXQ0Jg/8h04MBbhW/uruCTFcs9VhKP0LDhlOdkPtQqGqv5 vbzXLFcU0fLsS/NTymKTQkiKU5/KDo+AJP7X20I9i5vSJH5WVkS3MtvdsOJTUVQO2tDkV 2dKZrUCX5/SMNQ8DfY8FMKpzrFMWpqkebyyTw5zx8C2Jp/IWwVMtgK031aZ+sloohTQ== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1792538969; h=Received:DKIM-Signature:Message-ID:From:Subject:Reply-To:To:Cc: In-Reply-To:References:Content-Type:Content-Transfer-Encoding:Date; bh=M+fwSJW22ARR5gNr/Bn5tV99OMoOBSslMq3sJNMzJO8=; b=fJD9BdyuVzNedqZdU0M+cfVPfIQuhswipltuLybjcfWgdxPUdIwD2pBCucRzaJVj+rw9 PzYQ4NFpoUL/YlK32uwGMOxMkn2ExYQWHsydUpqns1KhR8vnAk51375LIyZTboETpDnag HDIz1rvRqu6YVRNXnn/Y76WUKKBHWvoRB8sIFcbzhTtYr5cB7ixzhG/RuScB8ea/+6rLo XHaN/vxq8irz2Qj/+CyfmFkqmIl5fj0wYk8Po4DuwMeoyxT8QMvY5O4GzBt/2kIxwctrA tB+OLerK5GrPmPVCznQr7EvzB0DNA77aLpBPy5ckfRetj4+TiV8Oqq0qlNQ70b9tQow== 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=YMufEW6E; 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) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 086D5606A31C for ; Tue, 20 Oct 2026 23:29:28 +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=YMufEW6E Received: by smtp.kernel.org (Postfix) with ESMTPSA id 63FE01F000C9; Tue, 20 Oct 2026 23:29:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1792538968; bh=M+fwSJW22ARR5gNr/Bn5tV99OMoOBSslMq3sJNMzJO8=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=YMufEW6EPF801pMMgzotOGaINIRq1pNfo3Dil5bnaVNGPA2uPmv40A8b1s40asU7p FUGF8iRAVlSOVTt2c6LXOblITV3al+8kM66w1MfZAEC7X3BL7Y0elgorBA/Fa5fiLi EAVo7iMvT/Eo7fOdJfjL6broOPIUYBQk1iSDUDL374MzaTh7CFYOCnzt5OaPakUH+s GrQQdALtKvcwxJHxPg+1zBcgHs6JoHqoH97W0OIzDZ3ZH8FN8oS1ennjqIXHl6GNzL JTMyiqtJylj6JL4wz1MAbGiN5pUisk198ZeQYPa2wdvOJlzoQIEELpUNT9RVMBGNrm 3vorCdgjdaZEQ== Message-ID: From: sashiko-bot@kernel.org Subject: Re: [PATCH v5 7/8] 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: <20261020205859.1080743-8-irogers@google.com> References: <20261019220915.3943592-1-irogers@google.com> <20261020205859.1080743-1-irogers@google.com> <20261020205859.1080743-8-irogers@google.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Tue, 20 Oct 2026 23:29:27 +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/20261020205859.1080= 743-1-irogers@google.com?part=3D7