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=-4.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,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 CC26EC43219 for ; Sat, 27 Apr 2019 10:43:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9BFEB2087C for ; Sat, 27 Apr 2019 10:43:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726053AbfD0Kmw (ORCPT ); Sat, 27 Apr 2019 06:42:52 -0400 Received: from mx1.redhat.com ([209.132.183.28]:48804 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725871AbfD0Kmw (ORCPT ); Sat, 27 Apr 2019 06:42:52 -0400 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 2CF29368B1; Sat, 27 Apr 2019 10:42:52 +0000 (UTC) Received: from prarit.bos.redhat.com (prarit-guest.khw1.lab.eng.bos.redhat.com [10.16.200.63]) by smtp.corp.redhat.com (Postfix) with ESMTP id 7D44D60C82; Sat, 27 Apr 2019 10:42:51 +0000 (UTC) Subject: Re: [-next] system hangs likely due to "modules: Only return -EEXIST for modules that have finished loading" To: Heiko Carstens Cc: Jessica Yu , linux-next@vger.kernel.org, linux-kernel@vger.kernel.org, linux-s390@vger.kernel.org, Cathy Avery References: <20190426130736.GB8646@osiris> <20190426150741.GD8646@osiris> <20190426160956.GA3827@linux-8ccs> <2e047a7e-bf08-be8c-bdd0-429464fa133d@redhat.com> <52c293e9-ddfa-426a-a8f1-2106e250e78d@redhat.com> <20190427102440.GA28889@osiris> From: Prarit Bhargava Message-ID: <6a69074a-e913-3b67-feef-9b62a7400f8a@redhat.com> Date: Sat, 27 Apr 2019 06:42:51 -0400 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.4.0 MIME-Version: 1.0 In-Reply-To: <20190427102440.GA28889@osiris> Content-Type: text/plain; charset=utf-8 Content-Language: en-GB Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.30]); Sat, 27 Apr 2019 10:42:52 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 4/27/19 6:24 AM, Heiko Carstens wrote: > > diff --git a/kernel/module.c b/kernel/module.c > index 410eeb7e4f1d..48748cfec991 100644 > --- a/kernel/module.c > +++ b/kernel/module.c > @@ -3585,6 +3585,7 @@ again: > finished_loading(mod->name)); > if (err) > goto out_unlocked; > + cond_resched(); > goto again; > } > err = -EEXIST; > Heiko, I'm testing on 2-cpu systems which appear to show the problem ~10% of the time. On another system I backed out my original patch to set a baseline, and noticed that occasionally the time to boot the system doubles from ~4 seconds to 9 seconds. Is this something you're also concerned with? P.