Messages in this thread | | | Date | Tue, 5 Feb 2002 21:46:46 +0100 | From | Pavel Machek <> | Subject | Re: [PATCH] Radix-tree pagecache for 2.5 |
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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 - 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/
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