Re: [PATCH] ksm: set anon_vma of first rmap_item of ksm page to page's anon_vma other than vma's anon_vma

From	Andrew Morton <akpm@linux-foundation.org>
Newsgroups	linux.kernel
Subject	Re: [PATCH] ksm: set anon_vma of first rmap_item of ksm page to page's anon_vma other than vma's anon_vma
Date	2016-06-24 01:50 +0200
Message-ID	<rNmxI-mm-9@gated-at.bofh.it> (permalink)
References	<rNd1n-2aV-9@gated-at.bofh.it>
Organization	linux.* mail to news gateway

Show all headers | View raw

On Thu, 23 Jun 2016 21:33:54 +0800 <zhouxianrong@huawei.com> wrote:

> From: z00281421 <z00281421@notesmail.huawei.com>
> 
> set anon_vma of first rmap_item of ksm page to page's anon_vma
> other than vma's anon_vma so that we can lookup all the forked
> vma of kpage via reserve map. thus we can try_to_unmap ksm page
> completely and reclaim or migrate the ksm page successfully and
> need not to merg other forked vma addresses of ksm page with
> building a rmap_item for it ever after.
> 
> a forked more mapcount ksm page with partially merged vma addresses and
> a ksm page mapped into non-VM_MERGEABLE vma due to setting MADV_MERGEABLE
> on one of the forked vma can be unmapped completely by try_to_unmap.
> 

hm, OK, so this is an efficiency increase rather than a functional
change?

If so, are you able to quantify the benefit?  ie, how much faster did
things get?

I'll queue it up and shall await Hugh review (please).

Back to linux.kernel | Previous | Next — Previous in thread | Find similar | Unroll thread

Thread

[PATCH] ksm: set anon_vma of first rmap_item of ksm page to page's anon_vma other than vma's anon_vma <zhouxianrong@huawei.com> - 2016-06-23 15:40 +0200
  Re: [PATCH] ksm: set anon_vma of first rmap_item of ksm page to  page's anon_vma other than vma's anon_vma Andrew Morton <akpm@linux-foundation.org> - 2016-06-24 01:50 +0200

csiph-web