Messages in this thread | | | Date | Wed, 19 Dec 2012 12:58:11 -0500 | From | Johannes Weiner <> | Subject | Re: [patch 7/7] mm: reduce rmap overhead for ex-KSM page copies created on swap faults |
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On Wed, Dec 19, 2012 at 02:01:19AM -0500, Simon Jeons wrote: > On Mon, 2012-12-17 at 13:12 -0500, Johannes Weiner wrote: > > When ex-KSM pages are faulted from swap cache, the fault handler is > > not capable of re-establishing anon_vma-spanning KSM pages. In this > > case, a copy of the page is created instead, just like during a COW > > break. > > > > These freshly made copies are known to be exclusive to the faulting > > VMA and there is no reason to go look for this page in parent and > > sibling processes during rmap operations. > > > > Use page_add_new_anon_rmap() for these copies. This also puts them on > > the proper LRU lists and marks them SwapBacked, so we can get rid of > > doing this ad-hoc in the KSM copy code. > > Is it just a code cleanup instead of reduce rmap overhead?
Both.
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