>> * If we're getting low cache hit rates, don't flush
>> processes to swap.
>> * If we're getting good cache hit rates, flush old, idle
>> processes to swap.
Rik> ... but I fail to see this one. If we get a low cache hit rate,
Rik> couldn't that just mean we allocated too little memory for the
Rik> cache ?
maybe more specific: If the hit-rate is low and the cache is already
70+% of the systems memory, the chances maybe slim that more cache is
going to improve the hit-rate.
I do not care much whether the cache is using 99% of the systems memory
or 50%. As long as there is free memory, using it for cache is great. I
care a lot if the cache takes down interactivity, because it pushes out
processes that it thinks idle, but that I need in 5 seconds. The caches
pressure against processes should decrease with the (relative) size of
the cache. Especially in low hit-rate situations.
OT: I asked the question before somewhere else. Are there interfaces to
the VM that expose the various cache sizes and, more important,
hit-rates to userland? I would love to see (or maybe help writing in my
free time) a tool to just visualize/analyze the efficiency of the VM
system.
Martin
-- ------------------------------------------------------------------ Martin Knoblauch | email: Martin.Knoblauch@TeraPort.de TeraPort GmbH | Phone: +49-89-510857-309 C+ITS | Fax: +49-89-510857-111 http://www.teraport.de | Mobile: +49-170-4904759 - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
This archive was generated by hypermail 2b29 : Sat Jun 30 2001 - 21:00:16 EST