From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756907AbeDZStg (ORCPT ); Thu, 26 Apr 2018 14:49:36 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:36892 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1753665AbeDZStV (ORCPT ); Thu, 26 Apr 2018 14:49:21 -0400 Date: Thu, 26 Apr 2018 21:49:19 +0300 From: "Michael S. Tsirkin" To: Mikulas Patocka Cc: James Bottomley , Michal Hocko , David Rientjes , dm-devel@redhat.com, eric.dumazet@gmail.com, netdev@vger.kernel.org, jasowang@redhat.com, Randy Dunlap , linux-kernel@vger.kernel.org, Matthew Wilcox , linux-mm@kvack.org, edumazet@google.com, Andrew Morton , virtualization@lists.linux-foundation.org, David Miller , Vlastimil Babka Subject: Re: [dm-devel] [PATCH v5] fault-injection: introduce kvmalloc fallback options Message-ID: <20180426214011-mutt-send-email-mst@kernel.org> References: <1524694663.4100.21.camel@HansenPartnership.com> <20180426125817.GO17484@dhcp22.suse.cz> <1524753932.3226.5.camel@HansenPartnership.com> <1524756256.3226.7.camel@HansenPartnership.com> <20180426184845-mutt-send-email-mst@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Apr 26, 2018 at 12:07:25PM -0400, Mikulas Patocka wrote: > > IIUC debug kernels mainly exist so people who experience e.g. memory > > corruption can try and debug the failure. In this case, CONFIG_DEBUG_SG > > will *already* catch a failure early. Nothing special needs to be done. > > The patch helps people debug such memory coprruptions (such as using DMA > API on the result of kvmalloc). That's my point. I don't think your patch helps debug any memory corruptions. With CONFIG_DEBUG_SG using DMA API already causes a BUG_ON, that's before any memory can get corrupted. -- MST