From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1153E30EF89; Wed, 5 Nov 2025 11:00:32 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=90.155.50.34 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762340437; cv=none; b=E/yEZJZ7mVQgZCaOomieixUoXkDK78rXDNk8C2IA6h43AR4xFGp2rBItvPj+puSYGjYCE6qf4HRmFgA9YiqZJWShq4d5Ux3S0LtUI5YoFDDtJwGUK+AQmcZf3LxkFaNq7aJlAcwbiKznFdFO/k10wGrDLLT0DnnQkMWr6E5Tjfg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762340437; c=relaxed/simple; bh=0frN4Ydex62MR9blW5nQL3JIscHl7H6SztNBiRDUr9A=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=FBZJ1/bQ8/xHQYegmk4prJPgt9yPF8SjVKu30/YsiE4Il+Z101yU+R506mZHzXLoY8O120FI/3aU0iHxnGryik8hdaiUlk6FZfxvQpy+GI8HCFjXSwkl9qoBF+gQUohyMgH6MttP3d+9pj3w//0y8nGxLJCv0UZrnEZT07FNJU0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=infradead.org; spf=none smtp.mailfrom=infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=iCKKnfn7; arc=none smtp.client-ip=90.155.50.34 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=infradead.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="iCKKnfn7" 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=r4dNssuBIX3kLf4QLulycGpF4N2z+mVGDeDOZbf0Sz4=; b=iCKKnfn7I2hblI+EDuOylvkM43 LWVWUtBVQ92Y+eg3+G2VO0cBfRv2Dl3ir418Qi8U2HDUgURG7fhtNKlqn+x0HbKL7J/xExY+IonBV R3wIxt3ILBNzHhSbJFWh9pXPLOOzSa56NwNX5SKILtXpijKahN5GOO+A11i8YpDKnOZs93dOc6Y0C NGwhl3ykyU5BLFaVf/4gcVDYes6Olwhn6c5baQovL6oFH6pDn/cD+PNr8aYkhI6RZ/xWF4f5ZD98Q MjR+lUS3u6oitkDAl9nJOCZE1Kdt+lzQN2+x8LTVA1KM1AoCb+QwMTbAFpw0jD2NBAId7BGBm2FJE rZvGz0Sw==; Received: from 77-249-17-252.cable.dynamic.v4.ziggo.nl ([77.249.17.252] helo=noisy.programming.kicks-ass.net) by casper.infradead.org with esmtpsa (Exim 4.98.2 #2 (Red Hat Linux)) id 1vGbFb-00000003i8h-0Lnl; Wed, 05 Nov 2025 11:00:28 +0000 Received: by noisy.programming.kicks-ass.net (Postfix, from userid 1000) id ED3FE300230; Wed, 05 Nov 2025 12:00:26 +0100 (CET) Date: Wed, 5 Nov 2025 12:00:26 +0100 From: Peter Zijlstra To: "Chen, Yu C" Cc: kernel test robot , Fernand Sieber , oe-lkp@lists.linux.dev, lkp@intel.com, linux-kernel@vger.kernel.org, x86@kernel.org, aubrey.li@linux.intel.com Subject: Re: [tip:sched/core] [sched/fair] 79104becf4: BUG:kernel_NULL_pointer_dereference,address Message-ID: <20251105110026.GI988547@noisy.programming.kicks-ass.net> References: <202510211205.1e0f5223-lkp@intel.com> <20251021110449.GO3245006@noisy.programming.kicks-ass.net> <20251027125453.GY4067720@noisy.programming.kicks-ass.net> <3b30e40b-f1fb-4145-b4d9-a9279b9602d8@intel.com> <20251027135516.GA3419281@noisy.programming.kicks-ass.net> <20251027140718.GT1386988@noisy.programming.kicks-ass.net> <20251027140959.GU1386988@noisy.programming.kicks-ass.net> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: On Tue, Oct 28, 2025 at 10:30:08AM +0800, Chen, Yu C wrote: > On 10/27/2025 10:09 PM, Peter Zijlstra wrote: > > On Mon, Oct 27, 2025 at 03:07:18PM +0100, Peter Zijlstra wrote: > > > On Mon, Oct 27, 2025 at 02:55:16PM +0100, Peter Zijlstra wrote: > > > > > > > > May I know if you are using the kernel config 0day attached? > > > > > I found that the config 0day attached > > > > > (https://download.01.org/0day-ci/archive/20251021/202510211205.1e0f5223-lkp@intel.com/config-6.18.0-rc1-00001-g79104becf42b) > > > > > has > > > > > CONFIG_IA32_EMULATION=y > > > > > CONFIG_IA32_EMULATION_DEFAULT_DISABLED=y > > > > > > Yep, deleting that entry makes it all work. > > > > 'work' might be over stating, it boots and starts trinity, which then > > promptly (as in a handful of seconds) triggers OOM and dies. Not > > actually reproducing the NULL deref I was looking for. > > Change the following line in job-script > export memory='16G' > to > export memory='64G' > ? Yes, that seems to help. > I had a try and can reproduce the NULL except at first run: Took me two runs, but yes, I can see it now. Anyway, this is two bugs in the robot, can we please fix all this to not happen again? - .config has 32bit disabled while robot provides 32bit images. Clearly the actual robot runs 64bit images and the reproduction should provide those too. - job description is inaccurate in the amount of memory required. The reproduction steps must exactly match what the real robot runs, not something else.