Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752771AbaAXTa7 (ORCPT ); Fri, 24 Jan 2014 14:30:59 -0500 Received: from bear.ext.ti.com ([192.94.94.41]:42112 "EHLO bear.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751448AbaAXTa6 (ORCPT ); Fri, 24 Jan 2014 14:30:58 -0500 Message-ID: <52E2BF5C.8060009@ti.com> Date: Fri, 24 Jan 2014 14:30:36 -0500 From: Santosh Shilimkar User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/17.0 Thunderbird/17.0 MIME-Version: 1.0 To: Konrad Rzeszutek Wilk CC: Yinghai Lu , Andrew Morton , Linus Torvalds , Ingo Molnar , "H. Peter Anvin" , Dave Hansen , , Russell King Subject: Re: [PATCH 1/3] memblock, nobootmem: Add memblock_virt_alloc_low() References: <1390590670-25901-1-git-send-email-yinghai@kernel.org> <1390590670-25901-4-git-send-email-yinghai@kernel.org> <20140124192536.GC17156@phenom.dumpdata.com> In-Reply-To: <20140124192536.GC17156@phenom.dumpdata.com> Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Friday 24 January 2014 02:25 PM, Konrad Rzeszutek Wilk wrote: > On Fri, Jan 24, 2014 at 11:11:10AM -0800, Yinghai Lu wrote: >> The new memblock_virt APIs are used to replaced old bootmem API. >> >> We need to allocate page below 4G for swiotlb. >> >> That should fix regression on Andrew's system that is using swiotlb. > > Please include the title of the patch that caused the regression. > I presume it is "mm/lib/swiotlb: Use memblock apis for early memory allocations" > > Interestingly enough when I asked about it: > > https://lkml.org/lkml/2013/11/9/280 > > > >> v_overflow_buffer = memblock_virt_alloc_align_nopanic( > >> + PAGE_ALIGN(io_tlb_overflow), > >> + PAGE_SIZE); > > > > Does this guarantee that the pages will be allocated below 4GB? > > > Yes. The memblock layer still allocates memory from lowmem. As I > mentioned, there is no change in the behavior than what is today > apart from just the interface change. > > How did that happend? Was there another patch in the series that altered > such assumption? > Actually it didn't. It was the misunderstanding on my side about the low_mem_max_addr being under 4GB, which is not always true especially for 64-bit systems which have no addressing limitations. Regards, Santosh -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/