From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ig0-f180.google.com (mail-ig0-f180.google.com [209.85.213.180]) by kanga.kvack.org (Postfix) with ESMTP id ACD706B0035 for ; Mon, 12 May 2014 01:16:39 -0400 (EDT) Received: by mail-ig0-f180.google.com with SMTP id c1so3401815igq.1 for ; Sun, 11 May 2014 22:16:39 -0700 (PDT) Received: from mail-ig0-x22b.google.com (mail-ig0-x22b.google.com [2607:f8b0:4001:c05::22b]) by mx.google.com with ESMTPS id pe7si8369022icc.60.2014.05.11.22.16.38 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Sun, 11 May 2014 22:16:39 -0700 (PDT) Received: by mail-ig0-f171.google.com with SMTP id c1so3366892igq.4 for ; Sun, 11 May 2014 22:16:38 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: <87tx8v4qin.fsf@tassilo.jf.intel.com> References: <1399552888-11024-1-git-send-email-kirill.shutemov@linux.intel.com> <87tx8v4qin.fsf@tassilo.jf.intel.com> Date: Mon, 12 May 2014 09:16:38 +0400 Message-ID: Subject: Re: [PATCHv2 0/2] remap_file_pages() decommission From: Konstantin Khlebnikov Content-Type: text/plain; charset=UTF-8 Sender: owner-linux-mm@kvack.org List-ID: To: Andi Kleen Cc: Armin Rigo , "Kirill A. Shutemov" , Andrew Morton , Linus Torvalds , Linux Kernel Mailing List , "linux-mm@kvack.org" , peterz@infradead.org, Ingo Molnar On Mon, May 12, 2014 at 7:36 AM, Andi Kleen wrote: > Armin Rigo writes: > >> Here is a note from the PyPy project (mentioned earlier in this >> thread, and at https://lwn.net/Articles/587923/ ). > > Your use is completely bogus. remap_file_pages() pins everything > and disables any swapping for the area. Wait, what's wrong with swapping pages from non-linear vmas? try_to_umap() can handle them, though not very effectively. Some time ago I was thinking about tracking rmap for non-linear vmas, something like second-level tree of sub-vmas stored in non-linear vma. This could be done using exising vm_area_struct, and in rmap tree everything will looks just as normal. We'll waste some kernel memory, but it also will remove complexity from rmap and make non-linear vmas usable for all filesystems not just for shmem. But it's not worth. I ACK killing it. Maybe we should keep flag on vma and hide/merge them in proc/maps. Bloating files/dirs in proc might be bigger problem than non-existent performance regression. > > -Andi > -- > ak@linux.intel.com -- Speaking for myself only > > -- > 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 -- 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