From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934101AbbLWAAO (ORCPT ); Tue, 22 Dec 2015 19:00:14 -0500 Received: from mga11.intel.com ([192.55.52.93]:61496 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933267AbbLWAAM (ORCPT ); Tue, 22 Dec 2015 19:00:12 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.20,466,1444719600"; d="scan'208";a="877113571" Date: Tue, 22 Dec 2015 17:00:10 -0700 From: Ross Zwisler To: Andrew Morton Cc: Ross Zwisler , linux-kernel@vger.kernel.org, "H. Peter Anvin" , "J. Bruce Fields" , "Theodore Ts'o" , Alexander Viro , Andreas Dilger , Dave Chinner , Ingo Molnar , Jan Kara , Jeff Layton , Matthew Wilcox , Thomas Gleixner , linux-ext4@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-nvdimm@ml01.01.org, x86@kernel.org, xfs@oss.sgi.com, Dan Williams , Matthew Wilcox , Dave Hansen Subject: Re: [PATCH v5 1/7] pmem: add wb_cache_pmem() to the PMEM API Message-ID: <20151223000010.GB24124@linux.intel.com> Mail-Followup-To: Ross Zwisler , Andrew Morton , linux-kernel@vger.kernel.org, "H. Peter Anvin" , "J. Bruce Fields" , Theodore Ts'o , Alexander Viro , Andreas Dilger , Dave Chinner , Ingo Molnar , Jan Kara , Jeff Layton , Matthew Wilcox , Thomas Gleixner , linux-ext4@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-nvdimm@ml01.01.org, x86@kernel.org, xfs@oss.sgi.com, Dan Williams , Matthew Wilcox , Dave Hansen References: <1450502540-8744-1-git-send-email-ross.zwisler@linux.intel.com> <1450502540-8744-2-git-send-email-ross.zwisler@linux.intel.com> <20151222144440.1ad9e076464f4751f3de6a1f@linux-foundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20151222144440.1ad9e076464f4751f3de6a1f@linux-foundation.org> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Dec 22, 2015 at 02:44:40PM -0800, Andrew Morton wrote: > On Fri, 18 Dec 2015 22:22:14 -0700 Ross Zwisler wrote: > > > The function __arch_wb_cache_pmem() was already an internal implementation > > detail of the x86 PMEM API, but this functionality needs to be exported as > > part of the general PMEM API to handle the fsync/msync case for DAX mmaps. > > > > One thing worth noting is that we really do want this to be part of the > > PMEM API as opposed to a stand-alone function like clflush_cache_range() > > because of ordering restrictions. By having wb_cache_pmem() as part of the > > PMEM API we can leave it unordered, call it multiple times to write back > > large amounts of memory, and then order the multiple calls with a single > > wmb_pmem(). > > > > @@ -138,7 +139,7 @@ static inline void arch_clear_pmem(void __pmem *addr, size_t size) > > else > > memset(vaddr, 0, size); > > > > - __arch_wb_cache_pmem(vaddr, size); > > + arch_wb_cache_pmem(addr, size); > > } > > > > reject. I made this > > arch_wb_cache_pmem(vaddr, size); > > due to Dan's > http://www.ozlabs.org/~akpm/mmots/broken-out/pmem-dax-clean-up-clear_pmem.patch The first argument seems wrong to me - in arch_clear_pmem() 'addr' and 'vaddr' are the same address, with the only difference being 'addr' has the __pmem annotation. As of this patch arch_wb_cache_pmem() follows the lead of the rest of the exported PMEM API functions and takes an argument that has the __pmem annotation, so I believe it should be: arch_wb_cache_pmem(addr, size); Without this I think you'll get a sparse warning. This will be fixed up in the next version of my series which build upon Dan's patches.