Messages in this thread | | | Date | Thu, 7 May 2009 12:32:40 -0400 (EDT) | From | Christoph Lameter <> | Subject | Re: [PATCH -mm] vmscan: make mapped executable pages the first class citizen |
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On Thu, 7 May 2009, Lee Schermerhorn wrote:
> > Another possibility may be to put the exec pages on the mlock list > > and scan the list if under extreme duress? > > Actually, you don't need to go thru the overhead of mucking with the > PG_mlocked flag which incurs the rmap walk on unlock, etc. If one sets > the the AS_UNEVICTABLE flag, the pages will be shuffled off the the > unevictable LRU iff we ever try to reclaim them. And, we do have the > function to scan the unevictable lru to "rescue" pages in a given > mapping should we want to bring them back under extreme load. We'd need > to remove the AS_UNEVICTABLE flag, first. This is how > SHM_LOCK/SHM_UNLOCK works.
We need some way to control this. If there would be a way to simply switch off eviction of exec pages (via /proc/sys/vm/never_reclaim_exec_pages or so) I'd use it.
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