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=1792783716; b=vkpTaTkPBs7xOuU4awMFV2kRe/C5ARNHty5SxLK2PXnxzzD9PBjY3O3W7IZAuNDf5NkM cyR+K43tNA2BqkJ1XxkhEqCkNuKiD+ZwStXQHWimTXyok7p/hwVyBOf5WK/ZJ6zq2SQtN 3aGFc+0sPC5GQ/RyWtm+dWouSoJjP8nSH+QDUu34suUI0WgKW45LarP7Hcj/qIjLsZq86 E19JTqmfsnE+yklHtWjQqu5L+N635VDSMQ/IkOhK++0KMZhjn9ape0yZ/n/6Q/0+IVxUo Ha4031Xqs1sHCD+0et9Rp4Iw3aGqZnSMarptQiTc/57WxrXcikRUZpsaYWw8jwROPCQ== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1792783716; h=Received:DKIM-Signature:Message-ID:From:Subject:Reply-To:To:Cc: In-Reply-To:References:Content-Type:Content-Transfer-Encoding:Date; bh=U2pl1BJNb9c18TxXqf8ewfYJk4DN7EGnl+qq+MTWxj8=; b=qx+HU9E/TppeQWwaNBt+vGrwKYi8c0fnzBLMoB8uXTdmRiVOLCF885YhitXFcJX61MWi 6PcQPbue8Dv77WGf3bOROL1EmyuBeBoIO6cISanfWjQV/i0xX1MadNoxH5kCXZYWN23Oz FjijSGNl8y7zz5TrOJLhz+VW+mnOhuwHZLPiBmi0bOvxEEi1z0agAlEfkprzNw4+pza6Q 8AIEwR811hFHYFMVHv2uPRpzLvJ0e6EoBry8FEh3dssDMXu1YDALg90M9/ZEUWTtjdcnU zFa1r6VRc8J4MQE2bcfqhRcjAO4h4bEE6Bx24OqP3+A+llIXTieMMYwucHvf/SnB5hg== 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=L3nRQzRW; 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 64087606A31D for ; Fri, 23 Oct 2026 19:28:36 +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=L3nRQzRW Received: by smtp.kernel.org (Postfix) with ESMTPSA id D0AAC1F031E0; Fri, 23 Oct 2026 19:28:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1792783716; bh=U2pl1BJNb9c18TxXqf8ewfYJk4DN7EGnl+qq+MTWxj8=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=L3nRQzRWik+y5DPFwQC3O1bSPg0GLDH9houFOmEl9wu9Eq/jQlBy/m1/ZxfLWnRGu nRLwUms9VzgiTMglQtazCbI8NIxOdTee9FkrshPzSGQkS79eCR5oZx7X0dMDvYYx04 vX5SeuMADoRiKb7rb3bKHKquXikBIRUN1DpSg2JoUA7SCE9orWkX/syKuVh17QF24X kFDyxnpGyiKmVPwhM3QkSacYW3UciE2jCTKyEEOGofrn8xbaq7WDnKXN/kxJ1QB+SY S0z0cQ4aZ60tTmBLtY45Y6mY6RJQVzwvS71CeKkDRikIYgZnTrVUC1/yWupQpm0eP0 FcexS6zIn5ySg== Message-ID: From: sashiko-bot@kernel.org Subject: Re: [PATCH v7 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: <20261023190558.3050796-11-irogers@google.com> References: <20261022203003.1779152-1-irogers@google.com> <20261023190558.3050796-1-irogers@google.com> <20261023190558.3050796-11-irogers@google.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Fri, 23 Oct 2026 19:28:35 +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/20261023190558.3050= 796-1-irogers@google.com?part=3D10