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 08B9F43AA5 for ; Tue, 16 Apr 2024 16:23:24 +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=1713284606; cv=none; b=jAqjPmWDbLH+DpPCQq+AEA2756476iUu8pmAuozeL0LKxalNFpsr70i+ePThsVSkiMWHDl/u6we5545qsy97fAQka6zqPnMlnEJwYWihMEEFCWi4iOx+SvW8F13FELxq//a6Psu1Fi9nj8a0dy8gW16LtzEXbFTg7FEDeNgYhkY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1713284606; c=relaxed/simple; bh=NqJNbQnkmhNwT2hjGCczzRCYVBXMl2cwjSjuwVmFj4U=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=CaMde9zhulN39Yp0cRaUpuiSMX2da4RFj6MYiVMNp+NfLnLeVoQoN/5jm+3k8WmFPBgvl4qIUm7LVCW+Kap7fUBbDqrEBByT+4NJXzOI5rfikyNUDJQpEx+mIa66ZNVG6ou/w4geNUWSmHFY/Rv0k7qCf9+v6ofjnfftTcVSa6M= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (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=gE0OzcRK; arc=none smtp.client-ip=90.155.50.34 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (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="gE0OzcRK" 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=ZR5n7juj1Hh+Zmj/fiVDbxN1QXrwOEQlxO/uA8d7SzI=; b=gE0OzcRKn8l0pqnUK+Ce8VuHYL 7VZh4vw6xOyBDxX48Ll5h2lrH5cb/3EE5can0Z6OBQs0wm6Or+MGjgfGxm9byZObjLdrGMkOGneWx NCN03a1SrlHAvmUfIxPhJEU/XIUg/1Suj8wIMJ1WvENb2ejltUro9opxhB1txahTV31cNiWgLxHNJ vwPSzmQX7T3I2cn30uY9/tmUsOhGU4fRTni6j0HJhmRImdJpLudxWNblw5wUtKVU/gKLThfi6hDgC n3AIaaIPLDoskosuvyhFJYvY2oPwW9+dXMH/FitD6/cnFS3lucK2Nl+lZYjyHbLLXPt+CpWWHtu3M HdHOjGFg==; Received: from j130084.upc-j.chello.nl ([24.132.130.84] helo=noisy.programming.kicks-ass.net) by casper.infradead.org with esmtpsa (Exim 4.97.1 #2 (Red Hat Linux)) id 1rwlaa-00000000v5r-07tL; Tue, 16 Apr 2024 16:23:20 +0000 Received: by noisy.programming.kicks-ass.net (Postfix, from userid 1000) id A93AE3002E1; Tue, 16 Apr 2024 18:23:19 +0200 (CEST) Date: Tue, 16 Apr 2024 18:23:19 +0200 From: Peter Zijlstra To: Igor Raits Cc: linux-kernel@vger.kernel.org, Ingo Molnar , slyich@gmail.com, wuyun.abel@bytedance.com, yu.c.chen@intel.com Subject: Re: 6.8 to 6.9.0-rc3: kernel NULL pointer dereference in pick_next_task_fair+0x89 Message-ID: <20240416162319.GG30852@noisy.programming.kicks-ass.net> References: 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, Apr 16, 2024 at 08:18:28AM +0200, Igor Raits wrote: > Hello all, > > We also see this issue quite frequently these days, however it gets > slightly hidden behind printk issue so that full stacktrace can't be > printed due to the deadlock. Who is we and how do you make it go bang? Having a semi reliable reproducer in hand would be a tremendous help. Anywya, I've had: schedtool -D -e bash -c "while :; make O=defconfig-build clean; make O=defconfig-build -j64; done" running for an hour or so now, but no luck :/