From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wi0-f177.google.com (mail-wi0-f177.google.com [209.85.212.177]) by kanga.kvack.org (Postfix) with ESMTP id D30386B0032 for ; Fri, 29 May 2015 21:18:55 -0400 (EDT) Received: by wifw1 with SMTP id w1so43034437wif.0 for ; Fri, 29 May 2015 18:18:55 -0700 (PDT) Received: from mail-wi0-f182.google.com (mail-wi0-f182.google.com. [209.85.212.182]) by mx.google.com with ESMTPS id op3si6564157wic.73.2015.05.29.18.18.53 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 29 May 2015 18:18:53 -0700 (PDT) Received: by wizo1 with SMTP id o1so42927784wiz.1 for ; Fri, 29 May 2015 18:18:53 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: <1432940350-1802-13-git-send-email-toshi.kani@hp.com> References: <1432940350-1802-1-git-send-email-toshi.kani@hp.com> <1432940350-1802-13-git-send-email-toshi.kani@hp.com> Date: Fri, 29 May 2015 18:18:52 -0700 Message-ID: Subject: Re: [PATCH v11 12/12] drivers/block/pmem: Map NVDIMM with ioremap_wt() From: Dan Williams Content-Type: text/plain; charset=UTF-8 Sender: owner-linux-mm@kvack.org List-ID: To: Toshi Kani Cc: Borislav Petkov , "H. Peter Anvin" , Thomas Gleixner , Ingo Molnar , Andrew Morton , Arnd Bergmann , Juergen Gross , Konrad Rzeszutek Wilk , "linux-nvdimm@lists.01.org" , Luis Rodriguez , X86 ML , "linux-kernel@vger.kernel.org" , Stefan Bader , Andy Lutomirski , linux-mm@kvack.org, Henrique de Moraes Holschuh , Christoph Hellwig On Fri, May 29, 2015 at 3:59 PM, Toshi Kani wrote: > From: Toshi Kani > > The pmem driver maps NVDIMM with ioremap_nocache() as we cannot > write back the contents of the CPU caches in case of a crash. > > This patch changes to use ioremap_wt(), which provides uncached > writes but cached reads, for improving read performance. > > Signed-off-by: Toshi Kani Acked-by: Dan Williams ...with the caveat that I'm going to follow in behind this series with generic ioremap_cache() enabling and converting pmem to use persistent_copy() / persistent_sync() when the arch/cpu has persistent memory synchronization instructions. After the conversion ioremap_wt() will still be there for the non-persistent_sync() capable case. -- 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