From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dan Williams Subject: Re: [RFC PATCH 0/7] evacuate struct page from the block layer Date: Wed, 18 Mar 2015 08:35:38 -0700 Message-ID: References: <20150316201640.33102.33761.stgit@dwillia2-desk3.amr.corp.intel.com> <550957B9.5050803@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Return-path: In-Reply-To: <550957B9.5050803@gmail.com> Sender: linux-arch-owner@vger.kernel.org To: Boaz Harrosh Cc: "linux-kernel@vger.kernel.org" , Jens Axboe , Christoph Hellwig , Al Viro , Andrew Morton , Linus Torvalds , linux-arch@vger.kernel.org, riel@redhat.com, "linux-nvdimm@lists.01.org" , Dave Hansen , linux-raid , mgorman@suse.de, linux-fsdevel , Matthew Wilcox List-Id: linux-raid.ids On Wed, Mar 18, 2015 at 3:47 AM, Boaz Harrosh wrote: > On 03/16/2015 10:25 PM, Dan Williams wrote: >> Avoid the impending disaster of requiring struct page coverage for what >> is expected to be ever increasing capacities of persistent memory. > > If you are saying "disaster", than we need to believe you. Or is there > a scientific proof for this. The same Moore's Law based extrapolation that Dave Chinner did to determine that major feature development on XFS may cease in 5 - 7 years. In Dave's words we're looking ahead to "lots and fast". Given the time scale of getting kernel changes out to end users in an enterprise kernel update the "dynamic page struct allocation" approach is already insufficient.