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 F12BFC4332F for ; Wed, 23 Nov 2022 13:35:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238210AbiKWNf4 (ORCPT ); Wed, 23 Nov 2022 08:35:56 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49160 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238818AbiKWNf3 (ORCPT ); Wed, 23 Nov 2022 08:35:29 -0500 Received: from madras.collabora.co.uk (madras.collabora.co.uk [46.235.227.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 43CB7643F for ; Wed, 23 Nov 2022 05:22:36 -0800 (PST) Received: from [192.168.2.109] (109-252-117-140.nat.spd-mgts.ru [109.252.117.140]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) (Authenticated sender: dmitry.osipenko) by madras.collabora.co.uk (Postfix) with ESMTPSA id 8042C6602AA3; Wed, 23 Nov 2022 13:22:34 +0000 (GMT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=collabora.com; s=mail; t=1669209755; bh=f4T+av3IOf/lreuEnjUCksu3kk3ljEDFeo3tLB/Kl94=; h=Date:Subject:From:To:Cc:References:In-Reply-To:From; b=Zun/KSYXO7Gb3+Cm755sPZ1PWDfC8XF2dsjrbyIEy2n6sVaBEsiwnjq0NU+SfL12S Sq9K5pulveyaB9H9SmbV7oQh1AqVHasRpIPVbsncgHEcb0YqoxzH6pPhHpVbh8Fxsw +4HEs4g282hO4Uun4rU75RtDGPQ29t7K+E5F1wfh4ARtj4E3czyc8usQqTz2Kl86g2 SFLUZXUS51jpXQos0yEvMhnqdlynpyOs+3qW5Pdw6OQg3zDsgTIE5VQnb8RHKvd4K2 J0NF7kB3PgYnBnjqvlphDT9/mpF7WjMQ8KNl1gyqetzQosYCTIK/wrB3lE82hw4ajC V6kqd+JAD4L7A== Message-ID: Date: Wed, 23 Nov 2022 16:22:32 +0300 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.4.1 Subject: Re: [PATCH v1] drm/scheduler: Fix lockup in drm_sched_entity_kill() Content-Language: en-US From: Dmitry Osipenko To: Luben Tuikov , =?UTF-8?Q?Christian_K=c3=b6nig?= , David Airlie , Daniel Vetter Cc: dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org References: <20221123001303.533968-1-dmitry.osipenko@collabora.com> In-Reply-To: <20221123001303.533968-1-dmitry.osipenko@collabora.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 11/23/22 03:13, Dmitry Osipenko wrote: > The drm_sched_entity_kill() is invoked twice by drm_sched_entity_destroy() > while userspace process is exiting or being killed. First time it's invoked > when sched entity is flushed and second time when entity is released. This > causes a lockup within wait_for_completion(entity_idle) due to how completion > API works. > > Calling wait_for_completion() more times than complete() was invoked is a > error condition that causes lockup because completion internally uses > counter for complete/wait calls. The complete_all() must be used instead > in such cases. > > This patch fixes lockup of Panfrost driver that is reproducible by killing > any application in a middle of 3d drawing operation. > > Fixes: 2fdb8a8f07c2 ("drm/scheduler: rework entity flush, kill and fini") > Signed-off-by: Dmitry Osipenko > --- > drivers/gpu/drm/scheduler/sched_entity.c | 2 +- > drivers/gpu/drm/scheduler/sched_main.c | 4 ++-- > 2 files changed, 3 insertions(+), 3 deletions(-) > > diff --git a/drivers/gpu/drm/scheduler/sched_entity.c b/drivers/gpu/drm/scheduler/sched_entity.c > index fe09e5be79bd..15d04a0ec623 100644 > --- a/drivers/gpu/drm/scheduler/sched_entity.c > +++ b/drivers/gpu/drm/scheduler/sched_entity.c > @@ -81,7 +81,7 @@ int drm_sched_entity_init(struct drm_sched_entity *entity, > init_completion(&entity->entity_idle); > > /* We start in an idle state. */ > - complete(&entity->entity_idle); > + complete_all(&entity->entity_idle); > > spin_lock_init(&entity->rq_lock); > spsc_queue_init(&entity->job_queue); > diff --git a/drivers/gpu/drm/scheduler/sched_main.c b/drivers/gpu/drm/scheduler/sched_main.c > index 6ce04c2e90c0..857ec20be9e8 100644 > --- a/drivers/gpu/drm/scheduler/sched_main.c > +++ b/drivers/gpu/drm/scheduler/sched_main.c > @@ -1026,7 +1026,7 @@ static int drm_sched_main(void *param) > sched_job = drm_sched_entity_pop_job(entity); > > if (!sched_job) { > - complete(&entity->entity_idle); > + complete_all(&entity->entity_idle); > continue; > } > > @@ -1037,7 +1037,7 @@ static int drm_sched_main(void *param) > > trace_drm_run_job(sched_job, entity); > fence = sched->ops->run_job(sched_job); > - complete(&entity->entity_idle); > + complete_all(&entity->entity_idle); > drm_sched_fence_scheduled(s_fence); > > if (!IS_ERR_OR_NULL(fence)) { Applied to drm-misc-next -- Best regards, Dmitry