From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qc0-f180.google.com (mail-qc0-f180.google.com [209.85.216.180]) by kanga.kvack.org (Postfix) with ESMTP id 331B96B0031 for ; Fri, 27 Dec 2013 13:48:18 -0500 (EST) Received: by mail-qc0-f180.google.com with SMTP id w7so8994367qcr.11 for ; Fri, 27 Dec 2013 10:48:17 -0800 (PST) Received: from shards.monkeyblade.net (shards.monkeyblade.net. [2001:4f8:3:36:211:85ff:fe63:a549]) by mx.google.com with ESMTP id j7si29345124qab.151.2013.12.27.10.48.16 for ; Fri, 27 Dec 2013 10:48:17 -0800 (PST) Date: Fri, 27 Dec 2013 13:48:14 -0500 (EST) Message-Id: <20131227.134814.345379118522548543.davem@davemloft.net> Subject: Re: [PATCH] remap_file_pages needs to check for cache coherency From: David Miller In-Reply-To: <20131227180018.GC4945@linux.intel.com> References: <20131227180018.GC4945@linux.intel.com> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: willy@linux.intel.com Cc: linux-mm@kvack.org, sparclinux@vger.kernel.org, linux-parisc@vger.kernel.org, linux-mips@linux-mips.org From: Matthew Wilcox Date: Fri, 27 Dec 2013 13:00:18 -0500 > It seems to me that while (for example) on SPARC, it's not possible to > create a non-coherent mapping with mmap(), after we've done an mmap, > we can then use remap_file_pages() to create a mapping that no longer > aliases in the D-cache. > > I have only compile-tested this patch. I don't have any SPARC hardware, > and my PA-RISC hardware hasn't been turned on in six years ... I noticed > this while wandering around looking at some other stuff. I suppose this is needed, but only in the case where the mapping is shared and writable, right? I don't see you testing those conditions, but with them I'd be OK with this change. -- 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