From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id D7ACACD343F for ; Thu, 7 May 2026 12:39:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: Content-Type:MIME-Version:References:In-Reply-To:Message-ID:Date:Subject:CC: To:From:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=zekQpqKpT4s8RFnUNKGxX5SxB87NjFnJjrLeVc/FR64=; b=sHNOcfy/PqgsaGVv7VaDOk/VBI B0JeQX5OY4X5zO/+az7fvuMronpYejsQw30jKKJWipbHRJfF5kK5FP6TRIZGqK2F3SsI0t6EoK137 T4ZGS3HegI7tsRiFZr4ipKGBhUXrboQVPjPcO9Ur4xLr6EymYWxY8z6HK6L75roXYEHbQhdIWL9eI tumJY+6WY9Lb9WkdVTP3o/Qlw09KJoIQyu6dsjGJA0R9GtogEkA8S0y5+s9Wbivd1Zp4xyQFtDaEr 2iKmEQwClPMUdKd3X4qaXmq3Q8avehXnjoaUuDWpxlGx414mQ3E/LuP5ChvsAslVcRvqN4YxCTm+Y JePH5uIg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wKy0K-00000003nBC-2lZP; Thu, 07 May 2026 12:39:00 +0000 Received: from pdx-out-013.esa.us-west-2.outbound.mail-perimeter.amazon.com ([34.218.115.239]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1wKy0H-00000003nAS-2RZo for linux-arm-kernel@lists.infradead.org; Thu, 07 May 2026 12:38:59 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.de; i=@amazon.de; q=dns/txt; s=amazoncorp2; t=1778157537; x=1809693537; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=zekQpqKpT4s8RFnUNKGxX5SxB87NjFnJjrLeVc/FR64=; b=WhRHeD4cv782QKyQimnLeSvhEmDxG0/8ShLc/aU00hJ5kcl8WdW1H011 pK8LdH+Rw6VWROQXpdhkCGWkmZ/MnRb9UKRgBFWdA9KSbT8Na7w5KCAoH KTABLrR6DnyHuOE0jgqeqViQa5cMSnZwD8czGsDfQR9UTYC6VZPUTuLJ4 A5anJ0n0muycIo4HvRzt30ymm1wIz6DzWN+uHnbLCxEyXPRsjC+d37kYK BTGPGFmwZ1oGYOr/ajs8/wRPq2qV1/ri0qagKlwRsmubUZNnS776GFaq/ MILyFdVBWAmxsRlkFxC/WtxSHJYJa8a6E6y9eD2h/LjjdIsWB7jRHSB7h w==; 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: MIME-Version: 1.0 X-Originating-IP: [10.13.238.31] 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 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260507_053857_697337_9E699130 X-CRM114-Status: GOOD ( 14.07 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org 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