Re: Rik`s ac12-pmap2 vs ac12-vanilla perfcomp

[Daniel Phillips <phillips@bonn-fries.net>]

On September 2, 2001 11:46 pm, Samium Gromoff wrote:
> Daniel Phillips wrote:
> > > One thing that goes away with rmaps is the need to scan process page tables.
> > It's possible that this takes enough load off L1 cache to produce the effects
>
>     I feel like that. 
>     actually there was a fear that the overhead of reverse map maintenance
>  will overthrow the gain on low loads, but in my case this isnt an issue.

Rik's patch can be optimized a lot by using a direct pointer to the pte in the
nonshared case, and perhaps a null rmap pointer in the kernel-only case (e.g.,
page cache).  If the non-optimized version is already performing better than the
traditional approach it's a very good sign.  This needs careful confirmation.

Measurements where you force your system into continuous swapping would be very
interesting.

--
Daniel