Re: [RFC] Limit the size of the pagecache

From: Nick Piggin
Date: Tue Jan 23 2007 - 22:01:17 EST


Christoph Lameter wrote:
This is a patch using some of Aubrey's work plugging it in what is IMHO the right way. Feel free to improve on it. I have gotten repeatedly requests to be able to limit the pagecache. With the revised VM statistics this is now actually possile. I'd like to know more about possible uses of such a feature.




It may be useful to limit the size of the page cache for various reasons
such as

1. Insure that anonymous pages that may contain performance
critical data is never subject to swap.

2. Insure rapid turnaround of pages in the cache.

So if these two aren't working properly at 100%, then I want to know the
reason why. Or at least see what the workload and the numbers look like.


3. Reserve memory for other uses? (Aubrey?)

Maybe. This is still a bad hack, and I don't like to legitimise such use
though. I hope Aubrey isn't relying on this alone for his device to work
because his customers might end up hitting fragmentation problems sooner
or later.

--
SUSE Labs, Novell Inc.
Send instant messages to your online friends http://au.messenger.yahoo.com -
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/