From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pa0-f70.google.com (mail-pa0-f70.google.com [209.85.220.70]) by kanga.kvack.org (Postfix) with ESMTP id A8B45830A8 for ; Thu, 21 Apr 2016 19:51:39 -0400 (EDT) Received: by mail-pa0-f70.google.com with SMTP id xm6so83559761pab.3 for ; Thu, 21 Apr 2016 16:51:39 -0700 (PDT) Received: from mail.linuxfoundation.org (mail.linuxfoundation.org. [140.211.169.12]) by mx.google.com with ESMTPS id e184si3208481pfe.83.2016.04.21.16.51.38 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 21 Apr 2016 16:51:38 -0700 (PDT) Date: Thu, 21 Apr 2016 16:51:38 -0700 From: Andrew Morton Subject: Re: [PATCH resend 0/3] mm: allow arch to override lowmem_page_address Message-Id: <20160421165138.a57be293ec370d5ea014e1ae@linux-foundation.org> In-Reply-To: <1460995497-24312-1-git-send-email-ard.biesheuvel@linaro.org> References: <1460995497-24312-1-git-send-email-ard.biesheuvel@linaro.org> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Ard Biesheuvel Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, lftan@altera.com, jonas@southpole.se, will.deacon@arm.com On Mon, 18 Apr 2016 18:04:54 +0200 Ard Biesheuvel wrote: > These patches allow the arch to define the page_to_virt() conversion that > is used in lowmem_page_address(). This is desirable for arm64, where this > conversion is trivial when CONFIG_SPARSEMEM_VMEMMAP is enabled, while > breaking it up into __va(PFN_PHYS(page_to_pfn(page))), as is done currently > in lowmem_page_address(), will force the use of a virt-to-phys() conversion > and back again, which always involves a memory access on arm64, since the > start of physical memory is not a compile time constant. > > I have split off these patches from my series 'arm64: optimize virt_to_page > and page_address' which I sent out 3 weeks ago, and resending them in the > hope that they can be picked up (with Will's ack on #3) to be merged via > the mm tree. > > I have cc'ed the nios2 and openrisc maintainers on previous versions, and > cc'ing them again now. I have dropped both of the arch specific mailing > lists, since one is defunct and the other is subscriber only. > > Andrew, is this something you would be pulling to pick up (assuming that you > agree with the contents)? Thanks. Looks OK to me and apart from the trivial openrisc/nios2 changes it's obviously a no-op for all-but-arm. So I suggest you include these patches in the appropriate arm tree. Acked-by: Andrew Morton -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org