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 X-Spam-Level: X-Spam-Status: No, score=-3.9 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8F42AC388F2 for ; Thu, 22 Oct 2020 08:37:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 457E82168B for ; Thu, 22 Oct 2020 08:37:50 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="B99Knje7"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="SBL2SbiG" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2509369AbgJVIht (ORCPT ); Thu, 22 Oct 2020 04:37:49 -0400 Received: from Galois.linutronix.de ([193.142.43.55]:46070 "EHLO galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2508247AbgJVIhs (ORCPT ); Thu, 22 Oct 2020 04:37:48 -0400 From: Thomas Gleixner DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1603355866; 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=QyrQSQmCRoE8e/yyUqmfECgKX4VgXOUeiqXGpq3mP/o=; b=B99Knje7mrFwyx04a4DftGWbzUOcUu5Q2wD49824cq5FfoSS6yVttHCESYzlP4uy+Io29N FF8KMUsdetdGVgt+iYV0r6eLMNEiVnt1fOXzX8h6Uxkx0tl1iC2TRQB+vR7UkmV+wXjUJ/ Hut1ewDzhQSVJNcC+6FNZdOrARtyNeBDoXLf2KnvpkZBm62uzIFHXgzZm6PPvHvLmXescC Hp8SN2W0SYT0Wgwe1T+vtvWjPZ/DpOzsmzlju1PPdqrYbvsB72+wPQt/mz78FjPnQMGeoP HmC9ZcYTWOd8nzEPIPAy/3GUV7d0AV2N0c5LGYr6+zI2oTObq79jpFnSYkGwKw== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1603355866; 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=QyrQSQmCRoE8e/yyUqmfECgKX4VgXOUeiqXGpq3mP/o=; b=SBL2SbiGQs74m8lQq8dx4auN2wtwVZkTfiXi6gnjnezfm5dpJdZhHv7gzNIyeeuhl0yb11 JAtMRK9rJNxqB+Cw== To: Pingfan Liu , linux-kernel@vger.kernel.org Cc: Pingfan Liu , Peter Zijlstra , Jisheng Zhang , Andrew Morton , "Guilherme G. Piccoli" , Petr Mladek , Marc Zyngier , Linus Walleij , afzal mohammed , Lina Iyer , "Gustavo A. R. Silva" , Maulik Shah , Al Viro , Jonathan Corbet , Pawan Gupta , Mike Kravetz , Oliver Neukum , linux-doc@vger.kernel.org, kexec@lists.infradead.org Subject: Re: [PATCH 0/3] warn and suppress irqflood In-Reply-To: <1603346163-21645-1-git-send-email-kernelfans@gmail.com> References: <1603346163-21645-1-git-send-email-kernelfans@gmail.com> Date: Thu, 22 Oct 2020 10:37:46 +0200 Message-ID: <871rhq7j1h.fsf@nanos.tec.linutronix.de> MIME-Version: 1.0 Content-Type: text/plain Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Oct 22 2020 at 13:56, Pingfan Liu wrote: > I hit a irqflood bug on powerpc platform, and two years ago, on a x86 platform. > When the bug happens, the kernel is totally occupies by irq. Currently, there > may be nothing or just soft lockup warning showed in console. It is better > to warn users with irq flood info. > > In the kdump case, the kernel can move on by suppressing the irq flood. You're curing the symptom not the cause and the cure is just magic and can't work reliably. Where is that irq flood originated from and why is none of the mechanisms we have in place to shut it up working? Thanks, tglx