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 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 14F7CC98321 for ; Fri, 25 Sep 2026 20:45:17 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id C4EDB10FC7A; Fri, 25 Sep 2026 20:45:16 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.b="MvGBaCTL"; dkim-atps=neutral Received: from tor.source.kernel.org (tor.source.kernel.org [172.105.4.254]) by gabe.freedesktop.org (Postfix) with ESMTPS id 78E0910FC7A for ; Fri, 25 Sep 2026 20:45:15 +0000 (UTC) Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by tor.source.kernel.org (Postfix) with ESMTP id B952A60136; Fri, 25 Sep 2026 20:45:14 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4F50B1F000FF; Fri, 25 Sep 2026 20:45:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1790369114; bh=KHnc1R9XMcGw4e29jWXaa0DZ6EpEy0wiKJatHc7jQb8=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=MvGBaCTL5rLi1qvl5nLEWImDApAALCnN9ntcO92LpAYrv3oShKvInaD5CbUImLi47 fV9F1AIWRZJJQC4BzBn+xVpaLveXhCBzoxZixaXaIp2lcrS5Vo9nhi3/lRxx92Mfp5 8tvMbVPiV3FeA/xMkb9fW3Ui2rzwwXqgcnrRnJfQsus0YcW0bi3/krh4TA7ec8pRDz uqALfCgpHVV7bysaYH0IJZK+CE4JolhqBEZSEE0xhQFDZjd3KHupb5J+9Q/1O9qk6Y cuGFJLHZNh1XTC0ZQkji8XtKz8VEPWytlNQLMJKAhuAx1RcXpSWl2hMu0KFhAO7VAJ u+yEEzFZvkOKA== From: sashiko-bot@kernel.org Subject: Re: [PATCH v8 21/24] drm/xe: Add ULLS migration job support to GuC submission To: "Matthew Brost" Cc: intel-xe@lists.freedesktop.org In-Reply-To: <20260925201526.1355279-22-matthew.brost@intel.com> References: <20260925201526.1355279-1-matthew.brost@intel.com> <20260925201526.1355279-22-matthew.brost@intel.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Fri, 25 Sep 2026 20:45:13 +0000 Message-Id: <20260925204514.4F50B1F000FF@smtp.kernel.org> X-BeenThere: intel-xe@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel Xe graphics driver List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: sashiko-reviews@lists.linux.dev Errors-To: intel-xe-bounces@lists.freedesktop.org Sender: "Intel-xe" Thank you for your contribution! Sashiko AI review found 1 potential issue(= s) to consider: - [High] drm/xe/guc: lost chained ULLS jobs when execution queue is suspend= ed -- commit 66f017eb1b046b1a95648616e5327a01247f461c Author: Matthew Brost drm/xe: Add ULLS migration job support to GuC submission This commit adds ULLS migration job support to the GuC submission backend.= =20 It reduces the max jobs on migration queues to match ULLS semaphores, skips= =20 writing the saved ring tail for non-first ULLS jobs, sets the ULLS semaphor= e=20 for chained jobs, and suppresses H2G submits for non-first ULLS jobs. > diff --git a/drivers/gpu/drm/xe/xe_guc_submit.c b/drivers/gpu/drm/xe/xe_g= uc_submit.c > index a2784763e72ba..cd9bb9f9e28c8 100644 > --- a/drivers/gpu/drm/xe/xe_guc_submit.c > +++ b/drivers/gpu/drm/xe/xe_guc_submit.c [ ... ] > @@ -1209,6 +1210,9 @@ static void submit_exec_queue(struct xe_exec_queue = *q, struct xe_sched_job *job) > if (exec_queue_suspended(q)) > return; > =20 > + if (xe_sched_job_ulls_is_chained(job)) > + xe_lrc_set_ulls_semaphore(lrc, xe_sched_job_lrc_seqno(job)); > + [Severity: High] Will this result in lost chained ULLS jobs if the execution queue is suspen= ded concurrently? If a chained ULLS job is submitted and the queue is suspended (for instance, due to preemption), submit_exec_queue() returns early at the exec_queue_suspended() check immediately preceding this addition. Because the early return completely skips the xe_lrc_set_ulls_semaphore()=20 call, when the queue resumes, the hardware will expect the memory semaphore= to=20 be signaled. Since the signaling was skipped, could this cause the hardware= to=20 wait indefinitely, triggering a job timeout and queue reset? [ ... ] --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20260925201526.1355= 279-1-matthew.brost@intel.com?part=3D21