From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (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 7F57313959C for ; Wed, 17 Apr 2024 15:08:21 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.133.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1713366504; cv=none; b=FGtmslHm2LMilYEYSCzlWLyjZt/rlNNDHNu+N0t0mRMrPyLn58dNM9QptCfpaEAzVb1dVeyvzXXOQPl5qNAhS0vhAx/W2E0GUxgCXnJerGn93tclnhk+eXvTnsjEg5NfgpUMfpwIsjnSKsN8vKwshVSfiydfk0zfh0NH0dm5uwI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1713366504; c=relaxed/simple; bh=G8xgs0TJ6NLjXmJLzGHFiLBY6t6LzdrcaViaEQIsWCs=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=G239aK3LYorvyX+2+cRk9SBuwZ4dZPHe3QkiREX9sXP7EW78VV6JGRkoBU2cZ+Iu+IsalQ3LIMqKfuR2YvLhkQCh69yB3pbsmXrQJZHfdbvtTDxD1eCtoFU91zlZPJvSMTQnDRSPa8W4jAmWq48A3KOEQwFQAvK+l82b+Xnr5Tc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=g5oAHbnF; arc=none smtp.client-ip=170.10.133.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="g5oAHbnF" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1713366500; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=+F4OvKnama+fi/vECsUu3ihfZcSjtcUfDj1tT/W9L28=; b=g5oAHbnFoca3NRm8YsGtSuuqXOWkf9YJ4VViFaFd4aB23BhlMlxXEE9R1dQDyrhyQ1JRbU dQzlLJzOWnX8kHLvXcYDQEVjK9JI4F8qH/OwQA1KB4PAiH0kVBHz5tfnsXMjFYaR0DFBqj 9eNNBqJCCfF3BBav3/w1BXUt9CW+BlU= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-342-VesNRI35Opul_7gtbJ7P5A-1; Wed, 17 Apr 2024 11:08:16 -0400 X-MC-Unique: VesNRI35Opul_7gtbJ7P5A-1 Received: from smtp.corp.redhat.com (int-mx10.intmail.prod.int.rdu2.redhat.com [10.11.54.10]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 231E210499A0; Wed, 17 Apr 2024 15:08:16 +0000 (UTC) Received: from localhost (unknown [10.42.28.23]) by smtp.corp.redhat.com (Postfix) with ESMTP id 5E0A3480F21; Wed, 17 Apr 2024 15:08:15 +0000 (UTC) Date: Wed, 17 Apr 2024 16:08:10 +0100 From: "Richard W.M. Jones" To: Johannes Weiner Cc: Chengming Zhou , Nhat Pham , Christian Heusel , Seth Jennings , Dan Streetman , Vitaly Wool , Andrew Morton , linux-mm@kvack.org, linux-kernel@vger.kernel.org, David Runge , Mark W , regressions@lists.linux.dev, Yosry Ahmed Subject: Re: [REGRESSION] Null pointer dereference while shrinking zswap Message-ID: <20240417150810.GA7636@redhat.com> References: <3iccc6vjl5gminut3lvpl4va2lbnsgku5ei2d7ylftoofy3n2v@gcfdvtsq6dx2> <246c1f4d-af13-40fa-b968-fbaf36b8f91f@linux.dev> <20240417143324.GA1055428@cmpxchg.org> 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: <20240417143324.GA1055428@cmpxchg.org> User-Agent: Mutt/1.5.21 (2010-09-15) X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.10 On Wed, Apr 17, 2024 at 10:33:24AM -0400, Johannes Weiner wrote: > I could reproduce the NULL crash locally with cgroup_disable=memory, > the shrinker enabled, and echo 3 >/proc/sys/vm/drop_caches. Can confirm that libguestfs uses cgroup_disable=memory for its appliance (as it saves some RAM and we don't need cgroups). Rich. -- Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones Read my programming and virtualization blog: http://rwmj.wordpress.com virt-builder quickly builds VMs from scratch http://libguestfs.org/virt-builder.1.html