From patchwork Tue Mar 7 14:25:36 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Asahi Lina X-Patchwork-Id: 13163707 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 gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 3B9DFC678D5 for ; Tue, 7 Mar 2023 14:28:08 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 4033310E4B0; Tue, 7 Mar 2023 14:28:07 +0000 (UTC) Received: from mail.marcansoft.com (marcansoft.com [212.63.210.85]) by gabe.freedesktop.org (Postfix) with ESMTPS id 51E1C10E4B0 for ; Tue, 7 Mar 2023 14:28:04 +0000 (UTC) Received: from [127.0.0.1] (localhost [127.0.0.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) (Authenticated sender: linasend@asahilina.net) by mail.marcansoft.com (Postfix) with ESMTPSA id E6EB8426E8; Tue, 7 Mar 2023 14:27:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=asahilina.net; s=default; t=1678199282; bh=mMV3DK/LniFSMGRFdp6WL8dzfr5kUnLaVi0jQqujgO4=; h=From:Date:Subject:References:In-Reply-To:To:Cc; b=YJhY78Ggk6+W6QBEOqupDX8aw5fWn6A/G56oEd7cyWJWvL0r748JHim/QFX3ga48h YlBahQ3QVQCtfglCOCwzF6GQnjnzKV0/4hYvwC31Y0uSRr4V+b3CUQ18zAkJuPAhzS ag95heC6renT1r1t7WaaCKqFa+8tqdzSsHCfhzZdGi7T9Kwk/2BnkgTAnLfc6MW1Au QQuJCcei56DnsCxfewGchiUhK7mQhwLnKfv3ijhcbx+NBUlpUiX39s0hxPnFjbzUg0 pFeU78xSX4yDPScrSCDZRGPIo+U0IsltRbUa79WeKf7JcpsOlh5dgZBcvyy0t2tEmP 6/bMok2XoIg2Q== From: Asahi Lina Date: Tue, 07 Mar 2023 23:25:36 +0900 Subject: [PATCH RFC 11/18] drm/scheduler: Clean up jobs when the scheduler is torn down MIME-Version: 1.0 Message-Id: <20230307-rust-drm-v1-11-917ff5bc80a8@asahilina.net> References: <20230307-rust-drm-v1-0-917ff5bc80a8@asahilina.net> In-Reply-To: <20230307-rust-drm-v1-0-917ff5bc80a8@asahilina.net> To: Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Daniel Vetter , Miguel Ojeda , Alex Gaynor , Wedson Almeida Filho , Boqun Feng , Gary Guo , =?utf-8?q?Bj=C3=B6rn_Roy_Baron?= , Sumit Semwal , =?utf-8?q?Christian_K=C3=B6nig?= , Luben Tuikov , Jarkko Sakkinen , Dave Hansen X-Mailer: b4 0.12.0 X-Developer-Signature: v=1; a=ed25519-sha256; t=1678199191; l=2245; i=lina@asahilina.net; s=20230221; h=from:subject:message-id; bh=mMV3DK/LniFSMGRFdp6WL8dzfr5kUnLaVi0jQqujgO4=; b=my5v1HGy930nc+3OP/Xw50JgUtnm2HGl3Rz4cVd2S5YoFUr5PVzWJZx9x3QmCcStWOHa4pvE4 +sIUSbGMdJ7CD+mn/ehaerq/gWofZP8Suo1RhZdOI9n3Y8dnSIkG167 X-Developer-Key: i=lina@asahilina.net; a=ed25519; pk=Qn8jZuOtR1m5GaiDfTrAoQ4NE1XoYVZ/wmt5YtXWFC4= X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linaro-mm-sig@lists.linaro.org, rust-for-linux@vger.kernel.org, Karol Herbst , asahi@lists.linux.dev, Asahi Lina , linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, Mary , Alyssa Rosenzweig , linux-sgx@vger.kernel.org, Ella Stanforth , Faith Ekstrand , linux-media@vger.kernel.org Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" drm_sched_fini() currently leaves any pending jobs dangling, which causes segfaults and other badness when job completion fences are signaled after the scheduler is torn down. Explicitly detach all jobs from their completion callbacks and free them. This makes it possible to write a sensible safe abstraction for drm_sched, without having to externally duplicate the tracking of in-flight jobs. This shouldn't regress any existing drivers, since calling drm_sched_fini() with any pending jobs is broken and this change should be a no-op if there are no pending jobs. Signed-off-by: Asahi Lina --- drivers/gpu/drm/scheduler/sched_main.c | 27 +++++++++++++++++++++++++-- 1 file changed, 25 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/scheduler/sched_main.c b/drivers/gpu/drm/scheduler/sched_main.c index 5c0add2c7546..0aab1e0aebdd 100644 --- a/drivers/gpu/drm/scheduler/sched_main.c +++ b/drivers/gpu/drm/scheduler/sched_main.c @@ -1119,10 +1119,33 @@ EXPORT_SYMBOL(drm_sched_init); void drm_sched_fini(struct drm_gpu_scheduler *sched) { struct drm_sched_entity *s_entity; + struct drm_sched_job *s_job, *tmp; int i; - if (sched->thread) - kthread_stop(sched->thread); + if (!sched->thread) + return; + + /* + * Stop the scheduler, detaching all jobs from their hardware callbacks + * and cleaning up complete jobs. + */ + drm_sched_stop(sched, NULL); + + /* + * Iterate through the pending job list and free all jobs. + * This assumes the driver has either guaranteed jobs are already stopped, or that + * otherwise it is responsible for keeping any necessary data structures for + * in-progress jobs alive even when the free_job() callback is called early (e.g. by + * putting them in its own queue or doing its own refcounting). + */ + list_for_each_entry_safe(s_job, tmp, &sched->pending_list, list) { + spin_lock(&sched->job_list_lock); + list_del_init(&s_job->list); + spin_unlock(&sched->job_list_lock); + sched->ops->free_job(s_job); + } + + kthread_stop(sched->thread); for (i = DRM_SCHED_PRIORITY_COUNT - 1; i >= DRM_SCHED_PRIORITY_MIN; i--) { struct drm_sched_rq *rq = &sched->sched_rq[i];