Re: [PATCH] mm/filemap.c: unconditionally call mark_page_accessed

Rik van Riel
2007-03-15T18:35:52Z

Valdis.Kletnieks@vt.edu wrote:
> On Wed, 14 Mar 2007 22:33:17 BST, Andreas Mohr said:
>
>> it'd seem we need some kind of state management here to figure out good
>> intervals of when to call mark_page_accessed() *again* for this page. E.g.
>> despite non-changing access patterns you could still call mark_page_accessed(
> )
>> every 32 calls or so to avoid expiry, but this would need extra helper
>> variables.
>
> What if you did something like
>
> if (jiffies%32) {...
>
> (Possibly scaling it so the low-order bits change). No need to lock it, as
> "right most of the time" is close enough.

Bad idea. That way you would only count page accesses if the
phase of the moon^Wjiffie is just right.

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