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=1792448373; b=1MFo3cwYxuxVDbP0peXlhsW2zWLBsYJ6Utnttl7dPMAnZN+VIJZ2krtQwAIpPS5OOa3i +YRkvNDiMSQeG9BJgbGZhGsd/fMnYh1wVOzkSAdsqk+EcYNHxUUmHeG5CjTnD7EcSpHzR 5ItklhVcmV1BKxFcrkE4vBoOJfFrcKzNSHz3kg7r/IjKIHuFI5kCG/9x68W2AHp84Fx95 nVVeCudqxbNe/hm15L2/y4sd5BQKAbT806Ose7XizzlnTJHj8D/TJm+OIFJSSFssSi/d1 /G9mMuXWrnBpGhE6XcjOZUsjLWmG5waqj1V7xkZL8Yg1XnvQY4EtoeRGuiHFRxkqo1g== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1792448373; h=Received:DKIM-Signature:Message-ID:From:Subject:Reply-To:To:Cc: In-Reply-To:References:Content-Type:Content-Transfer-Encoding:Date; bh=9bv8whaEZsL1jA+KwdtpBKYI9BEUa0UxIPPIu/lIe5U=; b=mgdiC30mMQtT8Xfx57dv3u2b0qTQZ/aiF74xzfOHnfbs/sgJezIbYzSn4X1FOM7OaaCL QEn7J8/V6o/uSlNc8Xo/WqjM7hixfGr5+BRPgNjIZ4SjBEIz5wTqdt6tTlxOjYoYKpUiF iZNeimNwLCSMZaPkQ5W8icXng2xBKbPjIGwcZiY7Jj6pP+7T8jqeujzKYQf5Q6vSRiVjj l0B3/JAbD3MkFuxBeZi2DAPA9aXp9CiVREhZFJAVWmyaM6VJO382US8kpiRYu/eQW0lhB Y9kL2WO/xQPtsNGkU4iPvMWtBtPuH8R7tCNT36WMSq2OSkM3O39OSuMsNdNoVkerFYg== 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=LSQodLFe; 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 137DB606A31F for ; Mon, 19 Oct 2026 22:19:32 +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=LSQodLFe Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6CA361F000C4; Mon, 19 Oct 2026 22:19:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1792448372; bh=9bv8whaEZsL1jA+KwdtpBKYI9BEUa0UxIPPIu/lIe5U=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=LSQodLFebxKSeG4y5YWRX8S8O2WUag20ZVyuWxoJZhPuwdmAbHJ1sOcdc4uvWThaB HPYsAZU2CDAiUlGvW3HTN5VKbFh5huTtDmbepwEhrLkA8m8AJ0QVD9pCQ2V7R5U8mx RU6sR+uGlj3sQl3WWOkFur0YH5/F0R+Lt02bEam2yuTwbEiVHueXAkipodO5scPVMZ t23c2lMQN1ieZyWnkxA3tCFvlietr0HbLx1UihJ+QcIaXRq0Wy2XcRVA5GwzxCx18S 71pCU4fz7Q8SYNtJgcqtY0WWEQPMGRvdr27vv8dgqY42BXYsdlyt/QhXBOyHRJn/Za Tktg2y7DxPU8A== Message-ID: From: sashiko-bot@kernel.org Subject: Re: [PATCH v4 6/7] 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: <20261019220915.3943592-7-irogers@google.com> References: <20261018053710.2572636-1-irogers@google.com> <20261019220915.3943592-1-irogers@google.com> <20261019220915.3943592-7-irogers@google.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Mon, 19 Oct 2026 22:19:31 +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/20261019220915.3943= 592-1-irogers@google.com?part=3D6