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=-8.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=ham 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 CC731C33CB2 for ; Wed, 29 Jan 2020 05:26:58 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [203.11.71.2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 7C85820720 for ; Wed, 29 Jan 2020 05:26:58 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7C85820720 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=ellerman.id.au Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 486sRh1y6hzDqR1 for ; Wed, 29 Jan 2020 16:26:56 +1100 (AEDT) Received: from ozlabs.org (bilbo.ozlabs.org [IPv6:2401:3900:2:1::2]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 486sDf5871zDqMn for ; Wed, 29 Jan 2020 16:17:22 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=ellerman.id.au Received: by ozlabs.org (Postfix, from userid 1034) id 486sDf2z6sz9s1x; Wed, 29 Jan 2020 16:17:22 +1100 (AEDT) X-powerpc-patch-notification: thanks X-powerpc-patch-commit: 4e0942c0302b5ad76b228b1a7b8c09f658a1d58a In-Reply-To: <20191016012536.22588-1-oohall@gmail.com> To: Oliver O'Halloran , linuxppc-dev@lists.ozlabs.org From: Michael Ellerman Subject: Re: [PATCH] powerpc/eeh: Only dump stack once if an MMIO loop is detected Message-Id: <486sDf2z6sz9s1x@ozlabs.org> Date: Wed, 29 Jan 2020 16:17:22 +1100 (AEDT) X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Sam Bobroff , Oliver O'Halloran Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" On Wed, 2019-10-16 at 01:25:36 UTC, Oliver O'Halloran wrote: > Many drivers don't check for errors when they get a 0xFFs response from an > MMIO load. As a result after an EEH event occurs a driver can get stuck in > a polling loop unless it some kind of internal timeout logic. > > Currently EEH tries to detect and report stuck drivers by dumping a stack > trace after eeh_dev_check_failure() is called EEH_MAX_FAILS times on an > already frozen PE. The value of EEH_MAX_FAILS was chosen so that a dump > would occur every few seconds if the driver was spinning in a loop. This > results in a lot of spurious stack traces in the kernel log. > > Fix this by limiting it to printing one stack trace for each PE freeze. If > the driver is truely stuck the kernel's hung task detector is better suited > to reporting the probelm anyway. > > Cc: Sam Bobroff > Signed-off-by: Oliver O'Halloran Applied to powerpc next, thanks. https://git.kernel.org/powerpc/c/4e0942c0302b5ad76b228b1a7b8c09f658a1d58a cheers