From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756669AbeDZPLj (ORCPT ); Thu, 26 Apr 2018 11:11:39 -0400 Received: from mail-pf0-f171.google.com ([209.85.192.171]:44615 "EHLO mail-pf0-f171.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756481AbeDZPLa (ORCPT ); Thu, 26 Apr 2018 11:11:30 -0400 X-Google-Smtp-Source: AIpwx4/PFJaVNVmJWtJvox1tDPUtx7Gi3Pcibg2fOl/M9BNO43PqAmXiNF0/uZwLhskGs/qqM03cHA== Subject: Re: [PATCH 2/5] ide: kill ide_toggle_bounce To: Christoph Hellwig Cc: iommu@lists.linux-foundation.org, linux-arch@vger.kernel.org, linux-block@vger.kernel.org, linux-ide@vger.kernel.org, linux-scsi@vger.kernel.org, netdev@vger.kernel.org, "David S. Miller" , linux-kernel@vger.kernel.org References: <20180424181625.22410-1-hch@lst.de> <20180424181625.22410-3-hch@lst.de> <5aaca0d3-417f-57f3-969f-b4c777c3fd48@kernel.dk> <20180426072033.GA14700@lst.de> From: Jens Axboe Message-ID: <682db9af-33bc-639d-8930-7a66c30bc644@kernel.dk> Date: Thu, 26 Apr 2018 09:11:21 -0600 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.0 MIME-Version: 1.0 In-Reply-To: <20180426072033.GA14700@lst.de> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 4/26/18 1:20 AM, Christoph Hellwig wrote: > On Tue, Apr 24, 2018 at 08:02:56PM -0600, Jens Axboe wrote: >> On 4/24/18 12:16 PM, Christoph Hellwig wrote: >>> ide_toggle_bounce did select various strange block bounce limits, including >>> not bouncing at all as soon as an iommu is present in the system. Given >>> that the dma_map routines now handle any required bounce buffering except >>> for ISA DMA, and the ide code already must handle either ISA DMA or highmem >>> at least for iommu equipped systems we can get rid of the block layer >>> bounce limit setting entirely. >> >> Pretty sure I was the one to add this code, when highmem page IO was >> enabled about two decades ago... >> >> Outside of DMA, the issue was that the PIO code could not handle >> highmem. That's not the case anymore, so this should be fine. > > Yes, that is the rationale. Any chance to you could look over the > other patches as well? Except for the networking one for which I'd > really like to see a review from Dave all the users of the interface > are block related. You can add my reviewed-by to 1-3, and 5. Looks good to me. -- Jens Axboe