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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id AA300C04FFF for ; Wed, 17 Apr 2024 15:08:26 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 2F7A36B008A; Wed, 17 Apr 2024 11:08:26 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 2A7B46B008C; Wed, 17 Apr 2024 11:08:26 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 196C96B0093; Wed, 17 Apr 2024 11:08:26 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0015.hostedemail.com [216.40.44.15]) by kanga.kvack.org (Postfix) with ESMTP id F124B6B008A for ; Wed, 17 Apr 2024 11:08:25 -0400 (EDT) Received: from smtpin15.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay07.hostedemail.com (Postfix) with ESMTP id AB275160E92 for ; Wed, 17 Apr 2024 15:08:25 +0000 (UTC) X-FDA: 82019354970.15.16B29E3 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by imf20.hostedemail.com (Postfix) with ESMTP id 84F2B1C0040 for ; Wed, 17 Apr 2024 15:08:23 +0000 (UTC) Authentication-Results: imf20.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=ZXEdElPq; spf=pass (imf20.hostedemail.com: domain of rjones@redhat.com designates 170.10.133.124 as permitted sender) smtp.mailfrom=rjones@redhat.com; dmarc=pass (policy=none) header.from=redhat.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1713366503; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=+F4OvKnama+fi/vECsUu3ihfZcSjtcUfDj1tT/W9L28=; b=Neu1l/lfhmrepxo3kExp01KcuKycO4XqawqCz6AkjqyVZtxBFla/MV3+df0p7J3R3lsgwn l+pWTb+OzCI+vaXN8/6Co59g7RqxZZwq011NGNBHVp3uDItjh1sX8olM2EQrAynkcczlC+ 5vFGM/klRDTEjKYzuV/nSY2zUkoNpFs= ARC-Authentication-Results: i=1; imf20.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=ZXEdElPq; spf=pass (imf20.hostedemail.com: domain of rjones@redhat.com designates 170.10.133.124 as permitted sender) smtp.mailfrom=rjones@redhat.com; dmarc=pass (policy=none) header.from=redhat.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1713366503; a=rsa-sha256; cv=none; b=yvkONbZkrxQwwVvUgw/Q2tTrAmNlUltslPhvaKczrArw+R6Rx4t2ram8zhXmxHWqhHZlvF ton5FzFqxw0An/tcSmhMluXoTR/dHhG3pCrI15+1Qit2S8M6cTslkvkY7XTSZLy3pPbT/e y1HGW6B2YNyjKnen0RMt47RtQQf5LNM= DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1713366502; 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=ZXEdElPqgCABSAkaAX66sV6VvGKAoJ5B6aIUtUimEnlq5odbtgffZJcjJRvZcIzwIyvAxF +A5Cr9v6TKKdr1WC2d0GjRLMIcCNdjEuFFDPPMmcafBOZTN9Kub4bKRIsQq+3A+NxTxi4f AXCpRaTmRH/3GByI9FA0MbWl5Xg8kEQ= 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> 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 X-Stat-Signature: a466ba4bnip3uf57ecbfefrfcx7uf6dc X-Rspamd-Queue-Id: 84F2B1C0040 X-Rspamd-Server: rspam02 X-Rspam-User: X-HE-Tag: 1713366503-149291 X-HE-Meta: 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 UVHPeGXo IUrnU2xA7n9jYiPm3UXZAXZv40ypDnrt5RHQ+RhiWzcW+ph8yebh8Xzgg9MPUGfov1V28gTVBar1WAaejUTjV2l4zn73ZbbIRE0IxnmMTdXCpM5eSABoHmaqt1mpXZRq5GjRQh6rnXAtp9ffDV/ZJsFg/Ob0UBDQaxbTC0cC3mf1LUXrSX+cdCxgq4N0aD9tge2M2xmKat0dokE+MkTKHjU4obmn5wWlzRsuCv7AYiC9KqXweYqT6OHomWCstxoRV/fthkteyHbnC3sgzlln/+f+Dt6gn+8bJ5p4qjHbvSlct4oLOBtSa76B0IsXCNnIlME7720KDUWaprhvd3LfmGBBpuU498+YQnHzv X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: 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