From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754551AbeDTJqJ (ORCPT ); Fri, 20 Apr 2018 05:46:09 -0400 Received: from verein.lst.de ([213.95.11.211]:41208 "EHLO newverein.lst.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754519AbeDTJqH (ORCPT ); Fri, 20 Apr 2018 05:46:07 -0400 Date: Fri, 20 Apr 2018 11:47:02 +0200 From: Christoph Hellwig To: Takashi Iwai Cc: Christoph Hellwig , iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH RFC] dma-direct: Try reallocation with GFP_DMA32 if possible Message-ID: <20180420094702.GA6530@lst.de> References: <20180416151819.27520-1-tiwai@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180416151819.27520-1-tiwai@suse.de> User-Agent: Mutt/1.5.17 (2007-11-01) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Apr 16, 2018 at 05:18:19PM +0200, Takashi Iwai wrote: > As the recent swiotlb bug revealed, we seem to have given up the > direct DMA allocation too early and felt back to swiotlb allocation. > The reason is that swiotlb allocator expected that dma_direct_alloc() > would try harder to get pages even below 64bit DMA mask with > GFP_DMA32, but the function doesn't do that but only deals with > GFP_DMA case. > > This patch adds a similar fallback reallocation with GFP_DMA32 as > we've done with GFP_DMA. The condition is that the coherent mask is > smaller than 64bit (i.e. some address limitation), and neither GFP_DMA > nor GFP_DMA32 is set beforehand. > > Signed-off-by: Takashi Iwai > > --- > > This is a resend of a test patch included in the previous thread > ("swiotlb: Fix unexpected swiotlb_alloc_coherent() failures"). I like the patch, but as-is it doesn't apply. Can you resend it against latest Linus' tree?