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SubjectRe: [PATCH] Radix-tree pagecache for 2.5
Hi!

> > > > > the biggest reason for this is that we *suck* at readahead for mmap....
> > > >
> > > > Is there not also fault overhead and similar issues related to mmap(2)
> > > > in general, that are not present with read(2)/write(2)?
> > >
> > > If a fault is more expensive than a system call, we're doing
> > > something wrong in the page fault path ;)
> >
> > You can read 128K at a time, but you can't fault 128K...
>
> Why not ?
>
> If the pages are present (read-ahead) and the page table
> is present, I see no reason why we couldn't fill in 32
> page table entries at once.

Ugh.

Okay, CPU will still have to fill its TLBs (it does not have to in
read case), but that is way easier operation.

I did not think about this possibility, sorry.
Pavel
--
(about SSSCA) "I don't say this lightly. However, I really think that the U.S.
no longer is classifiable as a democracy, but rather as a plutocracy." --hpa
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