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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id A5B78EB64DC for ; Thu, 29 Jun 2023 14:19:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232262AbjF2OTH (ORCPT ); Thu, 29 Jun 2023 10:19:07 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57240 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231952AbjF2OTB (ORCPT ); Thu, 29 Jun 2023 10:19:01 -0400 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9615035A9; Thu, 29 Jun 2023 07:19:00 -0700 (PDT) From: Thomas Gleixner DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1688048338; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=tcsyILS54G9Ylc5jhOd6kkhT9PsNGi7DVVNg0xcX1kQ=; b=UCd+zetdFtrupJKCxOImcOxEEYVwTwTvmkKbn8hKvfSyKXqMbmVcR1zCTJi+G+RViUHK4E Y9q0thPUWYdOXqChC/StMKF2R2w4nD0hiz4xNKzNr4M2EtQ9NRRA8SVB5G9U9ACtk2xCsc PPQzJRvOsyumV/NC0gxfmVzaLNrKIl7HMEum0BbZMP+z4ACCuvbpH/8tFtYyphMuz/I3Ef hJOKYUpeUcjpNpPvaR1IqKCZ8GNIwkjTdsfwv/jJzLmQWNviBAypnN++2aPu2bzOejUv2m s7vhMr6wZ13FsN0P7As3VIpwdBaOvI+TTGMvDuwJnHlIM4s5ANGzLA0w1l5wwg== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1688048338; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=tcsyILS54G9Ylc5jhOd6kkhT9PsNGi7DVVNg0xcX1kQ=; b=eVh4xcwU+ECp7+of3b7renU0kjswNCBP4itYsa/RB7p1Pb1FjkVIcc8e0ibcsLlhES1S79 66vXMUDddUHapCCQ== To: Vivek Anand , Peter Zijlstra Cc: Bagas Sanjaya , "Steven Rostedt (Google)" , Pablo Neira Ayuso , Jozsef Kadlecsik , Florian Westphal , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Lingutla Chandrasekhar , Frederic Weisbecker , "J. Avila" , "Rafael J. Wysocki" , Thomas Renninger , Shuah Khan , Borislav Petkov , Josh Poimboeuf , Linux Kernel Mailing List , Linux Regressions , Linux Netfilter Development , Netfilter Core Developers , Linux Networking , Linux Power Management , x86@kernel.org Subject: Re: Fwd: High cpu usage caused by kernel process when upgraded to linux 5.19.17 or later In-Reply-To: References: <01ac399d-f793-49d4-844b-72cd8e0034df@gmail.com> <20230627073035.GV4253@hirez.programming.kicks-ass.net> <99b64dfd-be4a-2248-5c42-8eb9197824e1@gmail.com> <20230627101939.GZ4253@hirez.programming.kicks-ass.net> Date: Thu, 29 Jun 2023 16:18:57 +0200 Message-ID: <878rc22vxq.ffs@tglx> MIME-Version: 1.0 Content-Type: text/plain Precedence: bulk List-ID: X-Mailing-List: netfilter-devel@vger.kernel.org On Thu, Jun 29 2023 at 12:05, Vivek Anand wrote: > I've tried booting with "spectre_v2=retpoline retbleed=off". > This change didn't work. Still CPU is 100% This does not make sense. retbleed=off has the same effect as CONFIG_X86_IBRS_ENTRY=n. The only difference is that with CONFIG_X86_IBRS_ENTRY=y and retbleed=off there is one extra jump in the low level entry code (syscall, interrupts, exceptions) and one extra jump on the exit side. But those extra jumps are completely irrelevant for the kworker threads. Can you please provide dmesg and the content of the files in /sys/devices/system/cpu/vulnerabilities/ on a kernel booted with "spectre_v2=retpoline retbleed=off" ? Thanks, tglx