From nobody Fri Oct 3 18:01:17 2025 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id B3AA41E520C; Wed, 27 Aug 2025 06:45:21 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=193.142.43.55 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756277123; cv=none; b=jEB4lEDNfyhpTQbzHZitD7qxeqLkTcvTuwOvBgt2N6uQ8zQ/451jr3+yisFMljD9qGOf/Ck0Bth5BAXz9HpdVwc+t6br2i6CORAhDVG1sJCZ3FpkiC8MsVtgEDX7/JysFMJDIQfHdxcD76pPReD+3hnTo0ulKOoqGToaa5N6ivc= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756277123; c=relaxed/simple; bh=4n3vCaPQp28RW2Mt27NfChjc+Yb5lJV4y6AosBbYjCI=; h=Date:From:To:Subject:Cc:In-Reply-To:References:MIME-Version: Message-ID:Content-Type; b=sYO1uDpLv2JcsOzLVUt5b6G0NFNkvukOB+fGbHiMI/UhLJqGmNycHp6wO9dnfUxsx3YUB1mgyLgtN5uPy9XytuLTPsizQHpNPv6wxBpVJyZ+89IVChMG3G9Isas+W5n+kDDnK7YiCqW+zKb7/d4PjKhJuCiVTIZH878/MwNGnWk= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de; spf=pass smtp.mailfrom=linutronix.de; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=Lb/pgR+a; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=jB5my3d5; arc=none smtp.client-ip=193.142.43.55 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linutronix.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="Lb/pgR+a"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="jB5my3d5" Date: Wed, 27 Aug 2025 06:45:14 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1756277119; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=psdguZ1Ssn+7A0tSYTSIx/6mRmbLjMtDHpA1rG9guqM=; b=Lb/pgR+a8sjew7VkX9clWGXNH6mD0TdyybQWEff05dc3fi2c7dwEwhwUTTMEQkVHkqC4Nz ZkQWnbzXcYuTS2sKdNLdpdi/MsVjPlxSimweb24quE1Vw7sDAbRVlKIRMrqkLnL4isoufk o4C31NYztneQ2NwAnaeZwhOt6CzGtAHdjKdIO+zzdlm04fetrBFc4JRDqo2AUo3ic61vML ywSUvl1b8mYWEnoTpz777h4GgU6f4k9sayZ6kN7AWWRaw5KDrNy2qKdyW+HjDHMJGMPeRy kP1jjqQkMXs1KGsLMkzEutDVRSTktwnFL4HOFStNdJN5frmKbigYyyCRsWXKNg== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1756277119; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=psdguZ1Ssn+7A0tSYTSIx/6mRmbLjMtDHpA1rG9guqM=; b=jB5my3d5BtZtXMEDtKoMdztPp1SQACxOiaKg/Xr3d5wIrxC1r3le7wzHcdHsaskSqmswvQ AnGVDZ+BSfXCmdAQ== From: "tip-bot2 for Josh Poimboeuf" Sender: tip-bot2@linutronix.de Reply-to: linux-kernel@vger.kernel.org To: linux-tip-commits@vger.kernel.org Subject: [tip: perf/core] perf: Skip user unwind if the task is a kernel thread Cc: Josh Poimboeuf , "Steven Rostedt (Google)" , "Peter Zijlstra (Intel)" , x86@kernel.org, linux-kernel@vger.kernel.org In-Reply-To: <20250820180428.930791978@kernel.org> References: <20250820180428.930791978@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-ID: <175627711485.1920.5265767868281233884.tip-bot2@tip-bot2> Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails Precedence: bulk Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable The following commit has been merged into the perf/core branch of tip: Commit-ID: 16ed389227651330879e17bd83d43bd234006722 Gitweb: https://git.kernel.org/tip/16ed389227651330879e17bd83d43bd23= 4006722 Author: Josh Poimboeuf AuthorDate: Wed, 20 Aug 2025 14:03:43 -04:00 Committer: Peter Zijlstra CommitterDate: Tue, 26 Aug 2025 09:51:13 +02:00 perf: Skip user unwind if the task is a kernel thread If the task is not a user thread, there's no user stack to unwind. Signed-off-by: Josh Poimboeuf Signed-off-by: Steven Rostedt (Google) Signed-off-by: Peter Zijlstra (Intel) Link: https://lore.kernel.org/r/20250820180428.930791978@kernel.org --- kernel/events/core.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/kernel/events/core.c b/kernel/events/core.c index f880cec..28de3ba 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -8198,7 +8198,8 @@ struct perf_callchain_entry * perf_callchain(struct perf_event *event, struct pt_regs *regs) { bool kernel =3D !event->attr.exclude_callchain_kernel; - bool user =3D !event->attr.exclude_callchain_user; + bool user =3D !event->attr.exclude_callchain_user && + !(current->flags & (PF_KTHREAD | PF_USER_WORKER)); /* Disallow cross-task user callchains. */ bool crosstask =3D event->ctx->task && event->ctx->task !=3D current; const u32 max_stack =3D event->attr.sample_max_stack;