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

From: Rik van Riel
Date: Thu Mar 15 2007 - 14:36:26 EST


Valdis.Kletnieks@xxxxxx 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.

--
Politics is the struggle between those who want to make their country
the best in the world, and those who believe it already is. Each group
calls the other unpatriotic.
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/