Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754150AbaA1BVm (ORCPT ); Mon, 27 Jan 2014 20:21:42 -0500 Received: from LGEMRELSE6Q.lge.com ([156.147.1.121]:50021 "EHLO LGEMRELSE6Q.lge.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751425AbaA1BVl (ORCPT ); Mon, 27 Jan 2014 20:21:41 -0500 X-AuditID: 9c930179-b7c84ae000000e38-36-52e70623ed22 Date: Tue, 28 Jan 2014 10:23:15 +0900 From: Minchan Kim To: Taras Glek Cc: John Stultz , KOSAKI Motohiro , "linux-mm@kvack.org" , LKML , Andrew Morton , Mel Gorman , Hugh Dickins , Dave Hansen , Rik van Riel , Michel Lespinasse , Johannes Weiner , Dhaval Giani , "H. Peter Anvin" , Android Kernel Team , Robert Love , Mel Gorman , Dmitry Adamushko , Dave Chinner , Neil Brown , Andrea Righi , Andrea Arcangeli , "Aneesh Kumar K.V" , Mike Hommey , Jan Kara , Rob Clark , Jason Evans , pliard@google.com Subject: Re: [PATCH v10 00/16] Volatile Ranges v10 Message-ID: <20140128012315.GE25066@bbox> References: <1388646744-15608-1-git-send-email-minchan@kernel.org> <20140128001244.GB25066@bbox> <52E6FCF3.6010009@linaro.org> <52E70367.1080504@mozilla.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <52E70367.1080504@mozilla.com> User-Agent: Mutt/1.5.21 (2010-09-15) X-Brightmail-Tracker: AAAAAA== Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jan 27, 2014 at 05:09:59PM -0800, Taras Glek wrote: > > > John Stultz wrote: > >On 01/27/2014 04:12 PM, Minchan Kim wrote: > >>On Mon, Jan 27, 2014 at 05:23:17PM -0500, KOSAKI Motohiro wrote: > >>>- Your number only claimed the effectiveness anon vrange, but not file vrange. > >>Yes. It's really problem as I said. > >> From the beginning, John Stultz wanted to promote vrange-file to replace > >>android's ashmem and when I heard usecase of vrange-file, it does make sense > >>to me so that's why I'd like to unify them in a same interface. > >> > >>But the problem is lack of interesting from others and lack of time to > >>test/evaluate it. I'm not an expert of userspace so actually I need a bit > >>help from them who require the feature but at a moment, > >>but I don't know who really want or/and help it. > >> > >>Even, Android folks didn't have any interest on vrange-file. > > > >Just as a correction here. I really don't think this is the case, as > >Android's use definitely relies on file based volatility. It might be > >more fair to say there hasn't been very much discussion from Android > >developers on the particulars of the file volatility semantics (out > >possibly not having any particular objections, or more-likely, being a > >bit too busy to follow the all various theoretical tangents we've > >discussed). > > > >But I'd not want anyone to get the impression that anonymous-only > >volatility would be sufficient for Android's needs. > Mozilla is starting to use android's ashmem for discardable memory > within a single process: > https://bugzilla.mozilla.org/show_bug.cgi?id=748598 . > > Volatile ranges do help with that specific(uncommon?) use of ashmem. Thanks for the info. I'd like to ask a question. Do you prefer fvrange(fd, offset, len) or fadvise(fd, offset, len, advise) inteface rather than current vrange syscall interface for vrange-file? Because I think it would remove unnecessary mmap/munmap syscall for vrange interface as well as out of address space in 32bit machine. > > For Mozilla sharing memory across processes via ashmem is not a > nearterm project. It's something that is likely to require > significant rework. Process-local discardable memory can be > retrofited in a more straight-forward fashion. > > Taras -- Kind regards, Minchan Kim -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/