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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 93A55C433FE for ; Sat, 19 Feb 2022 07:19:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241604AbiBSHTW (ORCPT ); Sat, 19 Feb 2022 02:19:22 -0500 Received: from mxb-00190b01.gslb.pphosted.com ([23.128.96.19]:57082 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229737AbiBSHTV (ORCPT ); Sat, 19 Feb 2022 02:19:21 -0500 Received: from verein.lst.de (verein.lst.de [213.95.11.211]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B74775F251; Fri, 18 Feb 2022 23:19:03 -0800 (PST) Received: by verein.lst.de (Postfix, from userid 2407) id 77C1268BEB; Sat, 19 Feb 2022 08:19:00 +0100 (CET) Date: Sat, 19 Feb 2022 08:19:00 +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, 42.hyeyoo@gmail.com, penberg@kernel.org, rientjes@google.com, iamjoonsoo.kim@lge.com, vbabka@suse.cz, David.Laight@ACULAB.COM, david@redhat.com, herbert@gondor.apana.org.au, davem@davemloft.net, linux-crypto@vger.kernel.org, steffen.klassert@secunet.com, netdev@vger.kernel.org, hca@linux.ibm.com, gor@linux.ibm.com, agordeev@linux.ibm.com, borntraeger@linux.ibm.com, svens@linux.ibm.com, linux-s390@vger.kernel.org, michael@walle.cc, linux-i2c@vger.kernel.org, wsa@kernel.org Subject: Re: [PATCH 22/22] mtd: rawnand: Use dma_alloc_noncoherent() for dma buffer Message-ID: <20220219071900.GH26711@lst.de> References: <20220219005221.634-1-bhe@redhat.com> <20220219005221.634-23-bhe@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220219005221.634-23-bhe@redhat.com> User-Agent: Mutt/1.5.17 (2007-11-01) Precedence: bulk List-ID: X-Mailing-List: linux-crypto@vger.kernel.org On Sat, Feb 19, 2022 at 08:52:21AM +0800, Baoquan He wrote: > Use dma_alloc_noncoherent() instead of directly allocating buffer > from kmalloc with GFP_DMA. DMA API will try to allocate buffer > depending on devices addressing limitation. I think it would be better to still allocate the buffer at allocation time and then just transfer ownership using dma_sync_single* in the I/O path to avoid the GFP_ATOMIC allocation.