From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pa0-f52.google.com (mail-pa0-f52.google.com [209.85.220.52]) by kanga.kvack.org (Postfix) with ESMTP id 43E2C6B0035 for ; Wed, 27 Aug 2014 16:06:16 -0400 (EDT) Received: by mail-pa0-f52.google.com with SMTP id bj1so1143604pad.11 for ; Wed, 27 Aug 2014 13:06:15 -0700 (PDT) Received: from mail.linuxfoundation.org (mail.linuxfoundation.org. [140.211.169.12]) by mx.google.com with ESMTPS id cz3si2621304pdb.38.2014.08.27.13.06.14 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 27 Aug 2014 13:06:14 -0700 (PDT) Date: Wed, 27 Aug 2014 13:06:13 -0700 From: Andrew Morton Subject: Re: [PATCH v10 00/21] Support ext4 on NV-DIMMs Message-Id: <20140827130613.c8f6790093d279a447196f17@linux-foundation.org> In-Reply-To: References: Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Matthew Wilcox Cc: linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, willy@linux.intel.com On Tue, 26 Aug 2014 23:45:20 -0400 Matthew Wilcox wrote: > One of the primary uses for NV-DIMMs is to expose them as a block device > and use a filesystem to store files on the NV-DIMM. While that works, > it currently wastes memory and CPU time buffering the files in the page > cache. We have support in ext2 for bypassing the page cache, but it > has some races which are unfixable in the current design. This series > of patches rewrite the underlying support, and add support for direct > access to ext4. Sat down to read all this but I'm finding it rather unwieldy - it's just a great blob of code. Is there some overall what-it-does-and-how-it-does-it roadmap? Some explanation of why one would use ext4 instead of, say, suitably-modified ramfs/tmpfs/rd/etc? Performance testing results? Carsten Otte wrote filemap_xip.c and may be a useful reviewer of this work. All the patch subjects violate Documentation/SubmittingPatches section 15 ;) -- 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