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 154121061B21 for ; Mon, 30 Mar 2026 19:50:52 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id D19FC10E76D; Mon, 30 Mar 2026 19:50:51 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=fail reason="signature verification failed" (2048-bit key; secure) header.d=infradead.org header.i=@infradead.org header.b="lrqLj7Op"; dkim-atps=neutral Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) by gabe.freedesktop.org (Postfix) with ESMTPS id A219C10E759; Mon, 30 Mar 2026 19:50:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=+/JZYP5QpagLtvYaNDs6zLVTNxiHm41ao7r0f9+QWbk=; b=lrqLj7OpiuMThbJqI0C+rxdc3Y /zT/e2U37UGCeJN4BGoYvwNO7fuW9fCCV3uZ/LUYDlUnTCU4gVBJMVBhK0WmVb/SMmJc5NX8gRKQC lxgLIATuxxsvk/wd5WGfYodYcGhjbnz8g/l+AApQfhp2OH651aAY67gAsBpLpZp5pCtW6XHzWe+t0 fe6WnnXuw0I/MrtS5fQtrF/q0cmsNisxm0YDGYMswtqKpN8wKrdn4Opkt3g1TGwW82tFiSHpouL7Z 201ALQBT5ALZqt/BqLS6IklEF/acxA+EHRnDai4pTyaYCuLaDercrVK3E9GXSQ/ZQ80Nwebke1sqA PjwU3t4w==; Received: from 2001-1c00-8d85-4b00-266e-96ff-fe07-7dcc.cable.dynamic.v6.ziggo.nl ([2001:1c00:8d85:4b00:266e:96ff:fe07:7dcc] helo=noisy.programming.kicks-ass.net) by casper.infradead.org with esmtpsa (Exim 4.98.2 #2 (Red Hat Linux)) id 1w7IdJ-00000007DfV-28lM; Mon, 30 Mar 2026 19:50:45 +0000 Received: by noisy.programming.kicks-ass.net (Postfix, from userid 1000) id 465E0301BDE; Mon, 30 Mar 2026 21:50:37 +0200 (CEST) Date: Mon, 30 Mar 2026 21:50:37 +0200 From: Peter Zijlstra To: "Borah, Chaitanya Kumar" Cc: willy@infradead.org, linux-kernel@vger.kernel.org, "intel-gfx@lists.freedesktop.org" , "intel-xe@lists.freedesktop.org" , "Kurmi, Suresh Kumar" , "Saarinen, Jani" , ravitejax.veesam@intel.com Subject: Re: Regression on linux-next (next-20260324 ) Message-ID: <20260330195037.GW2872@noisy.programming.kicks-ass.net> References: <20260327163100.GL3738010@noisy.programming.kicks-ass.net> <20260327164353.GM3739106@noisy.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: 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: , Errors-To: intel-xe-bounces@lists.freedesktop.org Sender: "Intel-xe" On Mon, Mar 30, 2026 at 01:56:33PM +0530, Borah, Chaitanya Kumar wrote: > > diff --git a/kernel/locking/ww_mutex.h b/kernel/locking/ww_mutex.h > > index b1834ab7e782..bb8b410779d4 100644 > > --- a/kernel/locking/ww_mutex.h > > +++ b/kernel/locking/ww_mutex.h > > @@ -42,7 +42,7 @@ __ww_waiter_last(struct mutex *lock) > > struct mutex_waiter *w = lock->first_waiter; > > if (w) > > - w = list_prev_entry(w, list); > > + w = __ww_waiter_prev(lock, w); > > return w; > > } > Thank you for the response, Peter. Unfortunately, the issue is still seen > with this change. Bah, indeed. Looking at this after the weekend I see that it's actually wrong. But I haven't yet had a new idea. I don't suppose there is a relatively easy way to reproduce this issue outside of your CI robot? My current working thesis is that since this is graphics, this is ww_mutex related. I'll go over this code once more...