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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id A89E1C433F5 for ; Tue, 14 Dec 2021 16:31:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233866AbhLNQb3 (ORCPT ); Tue, 14 Dec 2021 11:31:29 -0500 Received: from verein.lst.de ([213.95.11.211]:53114 "EHLO verein.lst.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232043AbhLNQb2 (ORCPT ); Tue, 14 Dec 2021 11:31:28 -0500 Received: by verein.lst.de (Postfix, from userid 2407) id 8628268AFE; Tue, 14 Dec 2021 17:31:24 +0100 (CET) Date: Tue, 14 Dec 2021 17:31:24 +0100 From: Christoph Hellwig To: Baoquan He Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, akpm@linux-foundation.org, hch@lst.de, cl@linux.com, John.p.donnelly@oracle.com, kexec@lists.infradead.org, stable@vger.kernel.org, Pekka Enberg , David Rientjes , Joonsoo Kim , Vlastimil Babka Subject: Re: [PATCH v3 5/5] mm/slub: do not create dma-kmalloc if no managed pages in DMA zone Message-ID: <20211214163124.GA21762@lst.de> References: <20211213122712.23805-1-bhe@redhat.com> <20211213122712.23805-6-bhe@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20211213122712.23805-6-bhe@redhat.com> User-Agent: Mutt/1.5.17 (2007-11-01) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Dec 13, 2021 at 08:27:12PM +0800, Baoquan He wrote: > Dma-kmalloc will be created as long as CONFIG_ZONE_DMA is enabled. > However, it will fail if DMA zone has no managed pages. The failure > can be seen in kdump kernel of x86_64 as below: Please just switch the sr allocation to use GFP_KERNEL without GFP_DMA. The block layer will do the proper bounce buffering underneath for the very unlikely case that we're actually using the single HBA driver that has ISA DMA addressing limitations. Same for the ch drive, btw.