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Re: vmem(9) (was Re: netbsd-6: pagedaemon freeze when low on memory)

Thor Lancelot Simon <> writes:

> On Tue, Mar 19, 2013 at 04:05:25PM -0400, Greg Troxel wrote:
>> This is perhaps overly complex, but it seems like all of the drain
>> routines need some sort of "how hard" parameter, because freeing cached
>> objects that haven't been accessed in 1000s doesn't really hurt, and as
>> you bring the stale lifetime down to 0s it begins to hurt more and be
>> thrashing.  So maybe that parameter really is in seconds.  This seems
>> consistent with the intent in the Bonwick paper, which does not explain
>> the strategy behind the back-end freeing mechanism (pool_drain, in our
>> terms).
> I think pools should be (slightly) leaky buckets.

So do you mean that pools should free a page every so often if it's
available, so that a pool's usage of unallocated pages decays as
e^-(t/60s), or something like that?

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