From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from pdx-out-013.esa.us-west-2.outbound.mail-perimeter.amazon.com (pdx-out-013.esa.us-west-2.outbound.mail-perimeter.amazon.com [34.218.115.239]) (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 D677C6DCE1 for ; Thu, 7 May 2026 12:38:53 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=34.218.115.239 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778157534; cv=none; b=bruI95cYnqsQVgL6OMUKaXh5k0pspfm/5Y2OT09oKNM5CMzXfYaw57MZhGtSerbfibrNZVAsUubB68lnHvOwSHZLb+VfSO/eJ7vFXcOR2uBKJ0p8rLMl9MSvuBQyVkpn/udcNvGyN8XkIdZ3DFkFhK1P7ZukDR2dbDN60KJbJZU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778157534; c=relaxed/simple; bh=zekQpqKpT4s8RFnUNKGxX5SxB87NjFnJjrLeVc/FR64=; h=From:To:CC:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=dryFLfBexSs0rvfBuL2KnzXOUzj5/U2JDnkvNmO7CvH6lZ3Ev7Ey8cbpbyGHQlA+s3GOlvOCZ/xYgOK084/0JC+AUexgaBTaDboOeMVrkGYKYrJ7oV7hIxlaOiyiCNy0fbY2H1NQ5evJVlOboSn9/det7yhfMpYU9SzpoWyRA3s= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=amazon.de; spf=pass smtp.mailfrom=amazon.de; dkim=pass (2048-bit key) header.d=amazon.de header.i=@amazon.de header.b=lZj1LxsG; arc=none smtp.client-ip=34.218.115.239 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=amazon.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=amazon.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=amazon.de header.i=@amazon.de header.b="lZj1LxsG" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.de; i=@amazon.de; q=dns/txt; s=amazoncorp2; t=1778157533; x=1809693533; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=zekQpqKpT4s8RFnUNKGxX5SxB87NjFnJjrLeVc/FR64=; b=lZj1LxsGZBqZs1Uzp32VG+HY3Ire7gKPyN6paHQ8Ua3tOTP1fdBEU9Ps +Fm4SlB7/esyZujqmH81jz00Uy1BXPMy5TenqrQnvDbk3xhzjxDMlAlsC QblAswwJd9mT3FzQSI4hgzdRNM9uUIFTy6Vr1Xchnb0jeI4h72XMMoZQd ktOeJ9WwJHUWuN693W3pNJw+/fV+7CXCrKHt24/rx1qc2EV7lOh4hwv8G fXpJBrQaLdVqyPEr/k3JV0nWJEXC17CxvE8kIMuYkvWTSgOvsXLJYdImM 2c1OvXcTg2A3IFgJacKCJNogIsryA5PPZcCVaFiNpxt/RLHqK+7GxQh4Y Q==; X-CSE-ConnectionGUID: 5X2Nbu3aT/u3joJ99P5Bew== X-CSE-MsgGUID: Ub7javUGSmqdHyK3PyBmMg== X-IronPort-AV: E=Sophos;i="6.23,221,1770595200"; d="scan'208";a="18889034" Received: from ip-10-5-6-203.us-west-2.compute.internal (HELO smtpout.naws.us-west-2.prod.farcaster.email.amazon.dev) ([10.5.6.203]) by internal-pdx-out-013.esa.us-west-2.outbound.mail-perimeter.amazon.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 07 May 2026 12:38:51 +0000 Received: from EX19MTAUWC002.ant.amazon.com [205.251.233.111:30294] by smtpin.naws.us-west-2.prod.farcaster.email.amazon.dev [10.0.37.224:2525] with esmtp (Farcaster) id d18333ff-2050-4e63-8c0d-e81be0ca1dec; Thu, 7 May 2026 12:38:51 +0000 (UTC) X-Farcaster-Flow-ID: d18333ff-2050-4e63-8c0d-e81be0ca1dec Received: from EX19D001UWA001.ant.amazon.com (10.13.138.214) by EX19MTAUWC002.ant.amazon.com (10.250.64.143) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA) id 15.2.2562.37; Thu, 7 May 2026 12:38:50 +0000 Received: from dev-dsk-dssauerw-1b-2c5f429c.eu-west-1.amazon.com (10.13.238.31) by EX19D001UWA001.ant.amazon.com (10.13.138.214) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA) id 15.2.2562.37; Thu, 7 May 2026 12:38:48 +0000 From: David Sauerwein To: Catalin Marinas CC: Will Deacon , Mark Rutland , , , Subject: Re: [PATCH] arm64: Fix garbled logs caused by race between multiple stack traces Date: Thu, 7 May 2026 12:38:46 +0000 Message-ID: <20260507123846.35621-1-dssauerw@amazon.de> X-Mailer: git-send-email 2.47.3 In-Reply-To: References: Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-ClientProxiedBy: EX19D045UWC004.ant.amazon.com (10.13.139.203) To EX19D001UWA001.ant.amazon.com (10.13.138.214) Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable On Wed, May 06, 2026 at 11:58:44AM +0100, Catalin Marinas wrote: > While the above does solve the line splitting, the trace is still not > that readable as we get line interleaving. > > I wonder whether we could do something like dump_stack_lvl() at the > show_regs() level to synchronise the printing. If that works, we > wouldn't need the above change (which isn't incorrect but maybe we can > do better). I think the change is still needed in either case. Other threads can log something unrelated to the stack traces which can still cause the register lines to be broken. After all, use of pr_cont is discouraged. checkpatch.pl warns saying "Avoid logging continuation uses where feasible" when adding new callers of pr_cont. I agree though that forcing stack traces to be printed sequentially would help with readability. Maybe this can be added as a separate change. Thanks, David Amazon Web Services Development Center Germany GmbH Tamara-Danz-Str. 13 10243 Berlin Geschaeftsfuehrung: Christof Hellmis, Andreas Stieger Eingetragen am Amtsgericht Charlottenburg unter HRB 257764 B Sitz: Berlin Ust-ID: DE 365 538 597