Messages in this thread | | | Date | Mon, 14 Jun 2010 23:10:08 +0530 | From | Balbir Singh <> | Subject | Re: [RFC/T/D][PATCH 2/2] Linux/Guest cooperative unmapped page cache control |
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* Avi Kivity <avi@redhat.com> [2010-06-14 18:34:58]:
> On 06/14/2010 06:12 PM, Dave Hansen wrote: > >On Mon, 2010-06-14 at 14:18 +0530, Balbir Singh wrote: > >>1. A slab page will not be freed until the entire page is free (all > >>slabs have been kfree'd so to speak). Normal reclaim will definitely > >>free this page, but a lot of it depends on how frequently we are > >>scanning the LRU list and when this page got added. > >You don't have to be freeing entire slab pages for the reclaim to have > >been useful. You could just be making space so that _future_ > >allocations fill in the slab holes you just created. You may not be > >freeing pages, but you're reducing future system pressure. > > Depends. If you've evicted something that will be referenced soon, > you're increasing system pressure. >
I don't think slab pages care about being referenced soon, they are either allocated or freed. A page is just a storage unit for the data structure. A new one can be allocated on demand.
-- Three Cheers, Balbir
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