Re: Minutes from Feb 21 LSE Call

Martin J. Bligh
2003-02-25T20:58:53Z

>> > the only solution is to do rmap lazily, i.e. to start building the rmap
>> > during swapping by walking the pagetables, basically exactly like I
>> > refill the lru with anonymous pages only after I start to need this
>> > information recently in my 2.4 tree, so if you never need to pageout
>> > heavily several giga of ram (like most of very high end numa servers),
>> > you'll never waste a single cycle in locking or whatever other
>> > worthless accounting overhead that hurts performance of all common
>> > workloads
>>
>> Did you see the partially object-based rmap stuff? I think that does
>> very close to what you want already.
>
> I don't see how it can optimize away the overhead but I didn't look at
> it for long.

Because you don't set up and tear down the rmap pte-chains for every
fault in / delete of any page ... it just works off the vmas.

M.