From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: MIME-Version: 1.0 In-Reply-To: <20151116194846.GB32203@linux.intel.com> References: <1447459610-14259-1-git-send-email-ross.zwisler@linux.intel.com> <1447459610-14259-4-git-send-email-ross.zwisler@linux.intel.com> <22E0F870-C1FB-431E-BF6C-B395A09A2B0D@dilger.ca> <20151116133714.GB3443@quack.suse.cz> <20151116140526.GA6733@quack.suse.cz> <20151116194846.GB32203@linux.intel.com> Date: Mon, 16 Nov 2015 12:34:55 -0800 Message-ID: Subject: Re: [PATCH v2 03/11] pmem: enable REQ_FUA/REQ_FLUSH handling From: Dan Williams Content-Type: text/plain; charset=UTF-8 Sender: owner-linux-mm@kvack.org To: Ross Zwisler , Dan Williams , Jan Kara , Andreas Dilger , "linux-kernel@vger.kernel.org" , "H. Peter Anvin" , "J. Bruce Fields" , Theodore Ts'o , Alexander Viro , Dave Chinner , Ingo Molnar , Jan Kara , Jeff Layton , Matthew Wilcox , Thomas Gleixner , linux-ext4 , linux-fsdevel , Linux MM , "linux-nvdimm@lists.01.org" , X86 ML , XFS Developers , Andrew Morton , Matthew Wilcox , Dave Hansen List-ID: On Mon, Nov 16, 2015 at 11:48 AM, Ross Zwisler wrote: > On Mon, Nov 16, 2015 at 09:28:59AM -0800, Dan Williams wrote: >> On Mon, Nov 16, 2015 at 6:05 AM, Jan Kara wrote: >> > On Mon 16-11-15 14:37:14, Jan Kara wrote: [..] > Is there any reason why this wouldn't work or wouldn't be a good idea? We don't have numbers to support the claim that pcommit is so expensive as to need be deferred, especially if the upper layers are already taking the hit on doing the flushes. REQ_FLUSH, means flush your volatile write cache. Currently all I/O through the driver never hits a volatile cache so there's no need to tell the block layer that we have a volatile write cache, especially when you have the core mm taking responsibility for doing cache maintenance for dax-mmap ranges. We also don't have numbers on if/when wbinvd is a more performant solution. tl;dr Now that we have a baseline implementation can we please use data to make future arch decisions? -- 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 From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751985AbbKPUe6 (ORCPT ); Mon, 16 Nov 2015 15:34:58 -0500 Received: from mail-wm0-f46.google.com ([74.125.82.46]:33693 "EHLO mail-wm0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751068AbbKPUe4 (ORCPT ); Mon, 16 Nov 2015 15:34:56 -0500 MIME-Version: 1.0 In-Reply-To: <20151116194846.GB32203@linux.intel.com> References: <1447459610-14259-1-git-send-email-ross.zwisler@linux.intel.com> <1447459610-14259-4-git-send-email-ross.zwisler@linux.intel.com> <22E0F870-C1FB-431E-BF6C-B395A09A2B0D@dilger.ca> <20151116133714.GB3443@quack.suse.cz> <20151116140526.GA6733@quack.suse.cz> <20151116194846.GB32203@linux.intel.com> Date: Mon, 16 Nov 2015 12:34:55 -0800 Message-ID: Subject: Re: [PATCH v2 03/11] pmem: enable REQ_FUA/REQ_FLUSH handling From: Dan Williams To: Ross Zwisler , Dan Williams , Jan Kara , Andreas Dilger , "linux-kernel@vger.kernel.org" , "H. Peter Anvin" , "J. Bruce Fields" , "Theodore Ts'o" , Alexander Viro , Dave Chinner , Ingo Molnar , Jan Kara , Jeff Layton , Matthew Wilcox , Thomas Gleixner , linux-ext4 , linux-fsdevel , Linux MM , "linux-nvdimm@lists.01.org" , X86 ML , XFS Developers , Andrew Morton , Matthew Wilcox , Dave Hansen Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Nov 16, 2015 at 11:48 AM, Ross Zwisler wrote: > On Mon, Nov 16, 2015 at 09:28:59AM -0800, Dan Williams wrote: >> On Mon, Nov 16, 2015 at 6:05 AM, Jan Kara wrote: >> > On Mon 16-11-15 14:37:14, Jan Kara wrote: [..] > Is there any reason why this wouldn't work or wouldn't be a good idea? We don't have numbers to support the claim that pcommit is so expensive as to need be deferred, especially if the upper layers are already taking the hit on doing the flushes. REQ_FLUSH, means flush your volatile write cache. Currently all I/O through the driver never hits a volatile cache so there's no need to tell the block layer that we have a volatile write cache, especially when you have the core mm taking responsibility for doing cache maintenance for dax-mmap ranges. We also don't have numbers on if/when wbinvd is a more performant solution. tl;dr Now that we have a baseline implementation can we please use data to make future arch decisions? From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dan Williams Subject: Re: [PATCH v2 03/11] pmem: enable REQ_FUA/REQ_FLUSH handling Date: Mon, 16 Nov 2015 12:34:55 -0800 Message-ID: References: <1447459610-14259-1-git-send-email-ross.zwisler@linux.intel.com> <1447459610-14259-4-git-send-email-ross.zwisler@linux.intel.com> <22E0F870-C1FB-431E-BF6C-B395A09A2B0D@dilger.ca> <20151116133714.GB3443@quack.suse.cz> <20151116140526.GA6733@quack.suse.cz> <20151116194846.GB32203@linux.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 To: Ross Zwisler , Dan Williams , Jan Kara , Andreas Dilger , "linux-kernel@vger.kernel.org" , "H. Peter Anvin" , "J. Bruce Fields" , "Theodore Ts'o" , Alexander Viro , Dave Chinner , Ingo Molnar , Jan Kara , Jeff Layton , Matthew Wilcox , Thomas Gleixner , linux-ext4 , linux-fsdevel , Linux MM , "linux-nvdimm@lists.01.org" , X86 ML , XFS Developers , Andrew Morton , Matthew Wilcox In-Reply-To: <20151116194846.GB32203@linux.intel.com> Sender: owner-linux-mm@kvack.org List-Id: linux-ext4.vger.kernel.org On Mon, Nov 16, 2015 at 11:48 AM, Ross Zwisler wrote: > On Mon, Nov 16, 2015 at 09:28:59AM -0800, Dan Williams wrote: >> On Mon, Nov 16, 2015 at 6:05 AM, Jan Kara wrote: >> > On Mon 16-11-15 14:37:14, Jan Kara wrote: [..] > Is there any reason why this wouldn't work or wouldn't be a good idea? We don't have numbers to support the claim that pcommit is so expensive as to need be deferred, especially if the upper layers are already taking the hit on doing the flushes. REQ_FLUSH, means flush your volatile write cache. Currently all I/O through the driver never hits a volatile cache so there's no need to tell the block layer that we have a volatile write cache, especially when you have the core mm taking responsibility for doing cache maintenance for dax-mmap ranges. We also don't have numbers on if/when wbinvd is a more performant solution. tl;dr Now that we have a baseline implementation can we please use data to make future arch decisions? -- 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 From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from relay.sgi.com (relay2.corp.sgi.com [137.38.102.29]) by oss.sgi.com (Postfix) with ESMTP id 538BF7CBF for ; Mon, 16 Nov 2015 14:35:02 -0600 (CST) Received: from cuda.sgi.com (cuda1.sgi.com [192.48.157.11]) by relay2.corp.sgi.com (Postfix) with ESMTP id 29184304032 for ; Mon, 16 Nov 2015 12:34:59 -0800 (PST) Received: from mail-wm0-f50.google.com (mail-wm0-f50.google.com [74.125.82.50]) by cuda.sgi.com with ESMTP id TNTqZMzPowfAt8Cc (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NO) for ; Mon, 16 Nov 2015 12:34:56 -0800 (PST) Received: by wmvv187 with SMTP id v187so196179633wmv.1 for ; Mon, 16 Nov 2015 12:34:55 -0800 (PST) MIME-Version: 1.0 In-Reply-To: <20151116194846.GB32203@linux.intel.com> References: <1447459610-14259-1-git-send-email-ross.zwisler@linux.intel.com> <1447459610-14259-4-git-send-email-ross.zwisler@linux.intel.com> <22E0F870-C1FB-431E-BF6C-B395A09A2B0D@dilger.ca> <20151116133714.GB3443@quack.suse.cz> <20151116140526.GA6733@quack.suse.cz> <20151116194846.GB32203@linux.intel.com> Date: Mon, 16 Nov 2015 12:34:55 -0800 Message-ID: Subject: Re: [PATCH v2 03/11] pmem: enable REQ_FUA/REQ_FLUSH handling From: Dan Williams List-Id: XFS Filesystem from SGI List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: xfs-bounces@oss.sgi.com Sender: xfs-bounces@oss.sgi.com To: Ross Zwisler , Dan Williams , Jan Kara , Andreas Dilger , "linux-kernel@vger.kernel.org" , "H. Peter Anvin" , "J. Bruce Fields" , Theodore Ts'o , Alexander Viro , Dave Chinner , Ingo Molnar , Jan Kara , Jeff Layton , Matthew Wilcox , Thomas Gleixner , linux-ext4 , linux-fsdevel , Linux MM , "linux-nvdimm@lists.01.org" , X86 ML , XFS Developers , Andrew Morton , Matthew Wilcox , Dave Hansen On Mon, Nov 16, 2015 at 11:48 AM, Ross Zwisler wrote: > On Mon, Nov 16, 2015 at 09:28:59AM -0800, Dan Williams wrote: >> On Mon, Nov 16, 2015 at 6:05 AM, Jan Kara wrote: >> > On Mon 16-11-15 14:37:14, Jan Kara wrote: [..] > Is there any reason why this wouldn't work or wouldn't be a good idea? We don't have numbers to support the claim that pcommit is so expensive as to need be deferred, especially if the upper layers are already taking the hit on doing the flushes. REQ_FLUSH, means flush your volatile write cache. Currently all I/O through the driver never hits a volatile cache so there's no need to tell the block layer that we have a volatile write cache, especially when you have the core mm taking responsibility for doing cache maintenance for dax-mmap ranges. We also don't have numbers on if/when wbinvd is a more performant solution. tl;dr Now that we have a baseline implementation can we please use data to make future arch decisions? _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs