Messages in this thread | | | Date | Tue, 23 Aug 2011 09:22:57 +1000 | From | Dave Chinner <> | Subject | Re: [PATCH 1/2] vmscan: fix initial shrinker size handling |
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On Mon, Aug 22, 2011 at 02:17:21PM +0300, Konstantin Khlebnikov wrote: > Shrinker function can returns -1, it means it cannot do anything without a risk of deadlock. > For example prune_super() do this if it cannot grab superblock refrence, even if nr_to_scan=0. > Currenly we interpret this like ULONG_MAX size shrinker, evaluate total_scan according this, > and next time this shrinker can get really big pressure. Let's skip such shrinkers instead. > > Also make total_scan signed, otherwise check (total_scan < 0) below never works.
I've got a patch set I am going to post out today that makes this irrelevant.
The patch set splits the shrinker api into 2 callbacks - a "count objects" callback and an "scan objects" callback, getting rid of this messy "pass nr-to_scan == 0 to count objects" wart altogether.
Cheers,
Dave. -- Dave Chinner david@fromorbit.com
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