From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pa0-f49.google.com (mail-pa0-f49.google.com [209.85.220.49]) by kanga.kvack.org (Postfix) with ESMTP id 69D606B0038 for ; Tue, 8 Oct 2013 00:35:36 -0400 (EDT) Received: by mail-pa0-f49.google.com with SMTP id ld10so8152048pab.8 for ; Mon, 07 Oct 2013 21:35:36 -0700 (PDT) Received: by mail-qa0-f49.google.com with SMTP id i13so79979qae.15 for ; Mon, 07 Oct 2013 21:35:33 -0700 (PDT) Message-ID: <52538B95.6080208@gmail.com> Date: Tue, 08 Oct 2013 00:35:33 -0400 From: KOSAKI Motohiro MIME-Version: 1.0 Subject: Re: [PATCH 05/14] vrange: Add new vrange(2) system call References: <5253404D.2030503@linaro.org> <52534331.2060402@zytor.com> <52534692.7010400@linaro.org> <525347BE.7040606@zytor.com> <525349AE.1070904@linaro.org> <52534AEC.5040403@zytor.com> <20131008001306.GD25780@bbox> <52535EE1.3060700@zytor.com> <20131008020847.GH25780@bbox> <52537326.7000505@gmail.com> <20131008030736.GA29509@bbox> In-Reply-To: <20131008030736.GA29509@bbox> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Minchan Kim Cc: KOSAKI Motohiro , "H. Peter Anvin" , John Stultz , LKML , Andrew Morton , Android Kernel Team , Robert Love , Mel Gorman , Hugh Dickins , Dave Hansen , Rik van Riel , Dmitry Adamushko , Dave Chinner , Neil Brown , Andrea Righi , Andrea Arcangeli , "Aneesh Kumar K.V" , Mike Hommey , Taras Glek , Dhaval Giani , Jan Kara , Michel Lespinasse , Rob Clark , "linux-mm@kvack.org" (10/7/13 11:07 PM), Minchan Kim wrote: > Hi KOSAKI, > > On Mon, Oct 07, 2013 at 10:51:18PM -0400, KOSAKI Motohiro wrote: >>> Maybe, int madvise5(addr, length, MADV_DONTNEED|MADV_LAZY|MADV_SIGBUS, >>> &purged, &ret); >>> >>> Another reason to make it hard is that madvise(2) is tight coupled with >>> with vmas split/merge. It needs mmap_sem's write-side lock and it hurt >>> anon-vrange test performance much heavily and userland might want to >>> make volatile range with small unit like "page size" so it's undesireable >>> to make it with vma. Then, we should filter out to avoid vma split/merge >>> in implementation if only MADV_LAZY case? Doable but it could make code >>> complicated and lost consistency with other variant of madvise. >> >> I haven't seen your performance test result. Could please point out URLs? > > https://lkml.org/lkml/2013/3/12/105 It's not comparison with and without vma merge. I'm interest how much benefit vmas operation avoiding have. -- 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