From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoph Hellwig Subject: Re: [PATCH v2 00/10] evacuate struct page from the block layer, introduce __pfn_t Date: Thu, 7 May 2015 18:18:07 +0200 Message-ID: <20150507161807.GA1671@lst.de> References: <20150506200219.40425.74411.stgit@dwillia2-desk3.amr.corp.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Dan Williams , Linux Kernel Mailing List , Boaz Harrosh , Jan Kara , Mike Snitzer , Neil Brown , Benjamin Herrenschmidt , Dave Hansen , Heiko Carstens , Chris Mason , Paul Mackerras , "H. Peter Anvin" , Christoph Hellwig , Alasdair Kergon , "linux-nvdimm@lists.01.org" , Ingo Molnar , Mel Gorman , Matthew Wilcox , Ross Zwisler , Rik van Riel , Martin Schwidefsky , Jens Axboe , Theodore Ts'o , "Martin K. Peter To: Linus Torvalds Return-path: Received: from verein.lst.de ([213.95.11.211]:54887 "EHLO newverein.lst.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751337AbbEGQSJ (ORCPT ); Thu, 7 May 2015 12:18:09 -0400 Content-Disposition: inline In-Reply-To: Sender: linux-fsdevel-owner@vger.kernel.org List-ID: On Wed, May 06, 2015 at 05:19:48PM -0700, Linus Torvalds wrote: > What is the primary thing that is driving this need? Do we have a very > concrete example? FYI, I plan to to implement RAID acceleration using nvdimms, and I plan to ue pages for that. The code just merge for 4.1 can easily support page backing, and I plan to use that for now. This still leaves support for the gigantic intel nvdimms discovered over EFI out, but given that I don't have access to them, and I dont know of any publically available there's little I can do for now. But adding on demand allocate struct pages for the seems like the easiest way forward. Boaz already has code to allocate pages for them, although not on demand but at boot / plug in time.