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=1793010651; b=1ssa5HokJVkf6WZONfhxPDcKJOEyOqfLHKW2ppscCpA/RZ++MAlYk9vWM8n7Kvamx6yj zVz+xP3VBxyIxdfl0xpJ7wYFQjvyfYllJ/MG5Y3Yxn2hfhB9AOzItjejJ4+eiQXQfjv5V LrjHzq2x8NKJrfDHh2QZ3Q067JcvmHtD5KKKQ85s0IjnMjnlc9qZpmr6FrTThfQWw1ePB 07tZV6GDaeLrW2Omh7KHjPiev0nVeLsIFO9beMRPyvyZqfRJHywFHrkuzQvBlk/tXoOpg q8s+3h3lbIIiGnPHgxwxZH7yDgan4VEbqCELc6EQt50INUL6DRo7eWSGNZuyw1Yn1Xw== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793010651; h=Received:DKIM-Signature:Message-ID:From:Subject:Reply-To:To:Cc: In-Reply-To:References:Content-Type:Content-Transfer-Encoding:Date; bh=uNSLtacrsK7bHGLP51jwm3YO9cG6z+JLjjWuid1wq0M=; b=mvrfOW8uFiOCM0NV0WWeDtv6H3W2n4xwEXzf0u9VI2VmXH+zMvgaspuJQmHRIiw3riMM DFZznqgaAI1KZOQ2ha8OP5n8Hj96RvlkFK5sw0oG4svogZvSN8qMqHoa9R5sMHQEXkxNn YZIlHohcAlnwhtoIf6bJcQDz14+jqRMZ06sfpcStrnlpk1tGKMTkwwe4HjAhQlk07gy1v rElVikEHXGeiOJd/HuYl7yucpBHOSePOWoCssYwxzjaSYN20E6HQThPWpdgBTINhtRXDI BAlCZuCjetPYRbazIhBygE6X7VTpAuLbN7VkL6bSbhHouWxeweJtLghNlLxuTECsNXw== 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=JUEak4td; 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 7DED7606A31B for ; Mon, 26 Oct 2026 10:30:51 +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=JUEak4td Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0359D1F01825; Mon, 26 Oct 2026 10:30:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793010651; bh=uNSLtacrsK7bHGLP51jwm3YO9cG6z+JLjjWuid1wq0M=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=JUEak4tdvmmFhWCxCf42oFJ6XTo9tD0eqtyHjtWgTfpPj/qxMA+4SPxUiHrTY+YAy RpecCT5N+Ucy2AAkej7u4SlE4uwmvSkogzdDIGZj0tJgGZer6EMfAs+dlKnjAvhbIs 1wBGvSxj+SxY5tNds3e8lk9EI48GEufiV4pAl8m4UGuDJGnueetKqPQBT0I6XRtmzk fIKVrZb4qopGZh157w2QTgMFne2GMNhSEsAuI1YHDw7KgI7qEm7iFCO7VDoIgB3yxN pxP5ZnFiGrG1NLpTFX95YxfNsO8MFSdxqjOzSPcBO/wKYMUg/AUDWVvpsVGCof4NEU Q6nrzN6eLgxMg== Message-ID: From: sashiko-bot@kernel.org Subject: Re: [PATCH perf-tools-next v12 10/10] 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: <20261026025735.546101-11-atomlin@atomlin.com> References: <20261026025735.546101-1-atomlin@atomlin.com> <20261026025735.546101-11-atomlin@atomlin.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Mon, 26 Oct 2026 10:30:50 +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()) > [ ... ] > prevention. >=20 > Tested-by: Ian Rogers > Reviewed-by: Ian Rogers > Signed-off-by: Aaron Tomlin Sashiko has reviewed this patch and found no issues. --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20261026025735.5461= 01-1-atomlin@atomlin.com?part=3D10