From nobody Sun Dec 28 10:39:51 2025 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4F6C8C4167B for ; Sat, 9 Dec 2023 01:52:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1574949AbjLIBwM (ORCPT ); Fri, 8 Dec 2023 20:52:12 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40596 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236000AbjLIBwK (ORCPT ); Fri, 8 Dec 2023 20:52:10 -0500 Received: from mail-pl1-x632.google.com (mail-pl1-x632.google.com [IPv6:2607:f8b0:4864:20::632]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 156D6172B for ; Fri, 8 Dec 2023 17:52:16 -0800 (PST) Received: by mail-pl1-x632.google.com with SMTP id d9443c01a7336-1d08a924fcfso24838025ad.2 for ; Fri, 08 Dec 2023 17:52:16 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1702086735; x=1702691535; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:sender:from:to:cc:subject:date:message-id:reply-to; bh=K1h100B6rjxyBFhxrdSH5Ur+K5ujhSlU9cdOG0Eg1zw=; b=f8zEuyxSOLLLwFoajahMGRTvF/B5r80n+uP7gCQ6XpWa9F3RMXE1GWmgagTchOC3Ig wsvpIiVEqE/h4wD6al3VFxE4OM08sLaCN10ubkw/SVsJYo226F1cKSxzglEI/Sp5NfFz Rn4wF283H0a7UGISO0g5fWn/5LM5SvOFgWLXAd45xgjryOTsLtBfY32JVa38FgzgtHKb /e0NNteJAtj0h/OGJFq1XGROxfP80kdCnayeu1fh46N6yAJEVt5OeYW7moidaiTnQbXu t5LwiXY9ie8Jm7P2h7+ygyGnPMrtQVrp7wCeHm0EHQ6cCehI27CQ7wm2xf686MGkNRId Ggjg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1702086735; x=1702691535; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:sender:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=K1h100B6rjxyBFhxrdSH5Ur+K5ujhSlU9cdOG0Eg1zw=; b=EidObgrieJ3VrCpTjxAAZUMPtq7sWB3bfQ6MMvAIovZ5Z0alQg9cgxs3IfAOI5MQtK q4OZaXpc2EGb6gAWN0MU56oX/0A6VsS9zBZqpvlX6TIOkSRqC/LkUR5Td1BuTxoP8PUB ZKbsZayonc08bIffVA1Jqe9bz67q3KjYEUDYS4dDoMwvmkARqnIgVlzexNAdzEfEKW9+ Kb3BWfi6qyPRkS7v+tlpjCb9O0TPcQI4BUFoqkap1CuX3MZn7W1+62rGzUZ6bLvtqold gkcMvfTq8dkPg1BHtJ4k7E1FYFelA9uf3wqtE7uPwgs1tKafienh4fbqumUj2olqu5Mp MT0w== X-Gm-Message-State: AOJu0YwG528utgUY80UHjt51njdmYLqTJsv8cfT6JOnZxxVcqkxr9hID EcC/Vz4vXbgJUz+gUJdKq7ZyGyIA3NcAlg== X-Google-Smtp-Source: AGHT+IHSp1UWhkp1RZkMgC5fh8wg1F0fMcJCJefjtVs2a8zJaGbmy/bnfWcus6mP69lpWNulTfSCAQ== X-Received: by 2002:a17:902:9f87:b0:1cc:5a74:b1df with SMTP id g7-20020a1709029f8700b001cc5a74b1dfmr1034535plq.2.1702086735356; Fri, 08 Dec 2023 17:52:15 -0800 (PST) Received: from bangji.hsd1.ca.comcast.net ([2601:647:6780:42e0:7a1f:1c3b:5ad2:1af2]) by smtp.gmail.com with ESMTPSA id f10-20020a170902ce8a00b001cc8cf4ad16sm2370142plg.246.2023.12.08.17.52.12 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 08 Dec 2023 17:52:13 -0800 (PST) Sender: Namhyung Kim From: Namhyung Kim To: Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , Borislav Petkov , Dave Hansen Cc: Peter Zijlstra , Arnaldo Carvalho de Melo , LKML , x86@kernel.org, Ravi Bangoria , Guilherme Amadio , Stephane Eranian Subject: [PATCH] x86/nmi: Rate limit unknown NMI messages Date: Fri, 8 Dec 2023 17:52:11 -0800 Message-ID: <20231209015211.357983-1-namhyung@kernel.org> X-Mailer: git-send-email 2.43.0.472.g3155946c3a-goog MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" On some AMD machines, unknown NMI messages were printed on the console continuously when using perf command with IBS. It was reported that it can slow down the kernel. Let's ratelimit the unknown NMI messages. Cc: Ravi Bangoria Cc: Guilherme Amadio Cc: Stephane Eranian Signed-off-by: Namhyung Kim Acked-by: Guilherme Amadio Acked-by: Ravi Bangoria --- arch/x86/kernel/nmi.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/arch/x86/kernel/nmi.c b/arch/x86/kernel/nmi.c index 17e955ab69fe..d23867901186 100644 --- a/arch/x86/kernel/nmi.c +++ b/arch/x86/kernel/nmi.c @@ -303,13 +303,13 @@ unknown_nmi_error(unsigned char reason, struct pt_reg= s *regs) =20 __this_cpu_add(nmi_stats.unknown, 1); =20 - pr_emerg("Uhhuh. NMI received for unknown reason %02x on CPU %d.\n", - reason, smp_processor_id()); + pr_emerg_ratelimited("Uhhuh. NMI received for unknown reason %02x on CPU = %d.\n", + reason, smp_processor_id()); =20 if (unknown_nmi_panic || panic_on_unrecovered_nmi) nmi_panic(regs, "NMI: Not continuing"); =20 - pr_emerg("Dazed and confused, but trying to continue\n"); + pr_emerg_ratelimited("Dazed and confused, but trying to continue\n"); } NOKPROBE_SYMBOL(unknown_nmi_error); =20 --=20 2.43.0.472.g3155946c3a-goog