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=1792550634; b=ds3757i7aJLxmHq4sBecAPgLU7P64cGwSAXkVGZRzrWWqDpivYck46zDAoRlcuLTzBER WZoS1ly5ojvxrv1xcqKW89/t0C1t3BngWMIEkfgTP4skQYDhC7SUVmF+ZA4urAczyzu9k ux4Nw4/FMx3Lj4kQLUsX9+bObeDzwgg8OdwTL3ZdKNqn5CVonKr1jO1rbR1W6VhOFNSi8 ltY9NINzQqQygOEMXftunS+EafCPteVz5p+wCqZPnDKqlsAu5IYfsWuD1Y6EcTMAsaPux 9Y4tZob2cHdfNew984CEJ8zPHU1VAJdJ/nKK0EhAZyTHlCvJ/sQSGCGkP9b5zftJkOw== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1792550634; h=Received:DKIM-Signature:Message-ID:From:Subject:Reply-To:To:Cc: In-Reply-To:References:Content-Type:Content-Transfer-Encoding:Date; bh=BQ5wgnGKfFh3+vzQB4m2jYm/naG7XdFVFAxoEgbH1Qg=; b=2rncMQSFert4aKNo22UTmwdn5ew38sldUbUKsDSQBxwdVzKnW1jgSs9bGrjShCK9zeOn dA370j2MIfpugp9pg9aBRMo3Rii6QRznY8Wa65WmhvSwrBgnOzZYXrHx/gHQauM39ze2d 4Qyxo9bjyEFD4u6F+p0t5jzg4P9BVAbBeqDQPPT/ziM5etx6VMTmyUh0yTi4V9cMLG5A2 2LZEb/J/bO07tdMxdO+5thv8Jfq4/TbWGauqAcHT3R2/hIxMPlvu+tPVx+z0AjtfCEVN9 q4Uehuehlq+XS4m/eidKLTrizguSKyW6UC33nJpxITpHzeXRR/C9lxSAJPWai4+MGJA== 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=FXGSpq3b; 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 585F7606A319 for ; Wed, 21 Oct 2026 02:43:54 +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=FXGSpq3b Received: by smtp.kernel.org (Postfix) with ESMTPSA id D42C01F000C9; Wed, 21 Oct 2026 02:43:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1792550633; bh=BQ5wgnGKfFh3+vzQB4m2jYm/naG7XdFVFAxoEgbH1Qg=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=FXGSpq3bq53ENx46gDzHNNtck2MrrCCwzUD+4u9pbwBnTCp5+cVb4ia2Bka7eJhZI W+HEyOpXrKUmLlo1Qsu+2W4ft5b2q74vyUmkkzIS0LXi/M+LHernO72YIwRfeQ4CFE 1IJ5bJQx/6VxAlIwTqFfqRW76I8CpAtz1ArwzC5NGFcM/Goq7zATvbokIXYOfOAtTZ CPMaIfsaoM4gRf35i1Hk+zWiXO6AGrYF0R2dvVmWsO3Bqw5zueZN3T4xcpOp5SDUkF 2Rg3KJ24/dO3zdxWVgdWT6U2yv21fuRl6tjsEX2HEb5dd6h0b1qFEk2+QkquRji07h 3s2TmOnSs//Kw== Message-ID: From: sashiko-bot@kernel.org Subject: Re: [PATCH perf-tools-next v9 6/6] perf ftrace: Filter extraneous functions in function graph tracer Reply-To: sashiko-reviews@lists.linux.dev To: "Aaron Tomlin" Cc: linux-perf-users@vger.kernel.org In-Reply-To: <20261021023337.809936-7-atomlin@atomlin.com> References: <20261021023337.809936-1-atomlin@atomlin.com> <20261021023337.809936-7-atomlin@atomlin.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Wed, 21 Oct 2026 02:43:53 +0000 X-Mailing-List: linux-perf-users@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list > When tracing with the function graph tracer using a targeted filter > (-G or --graph-funcs), users occasionally observe unrelated functions in > the trace output: >=20 > 1. Top-level functions (e.g. most notably > finish_task_switch.isra.0()) appearing before or alongside the > requested target function. This occurs because clearing and > rewriting set_graph_function creates a transient window where > remote CPUs still observe an empty filter (tracing all > functions) before RCU synchronisation completes, coupled with > perf ftrace sleeping in poll() on trace_pipe right as tracing > starts. >=20 > 2. Detached/orphan calls inside the target callgraph > (e.g. housekeeping_any_cpu() and arch_irq_work_raise()) > [ ... ] > detached orphan suppression, glob matching, deep stack > traversal, dropped-orphan recovery, and orphan exit collision > prevention. >=20 > Signed-off-by: Aaron Tomlin Sashiko has reviewed this patch and found no issues. --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20261021023337.8099= 36-1-atomlin@atomlin.com?part=3D6