At Fri, 13 Aug 1999 15:33:31 -0500,
Alan Cox <alc@cs.rice.edu> wrote:
>
> On Sat, Aug 14, 1999 at 04:57:45AM +0900, Hidetoshi Shimokawa wrote:
> > ...
> >
> > As for 21164 Alpha, it has 96KB 3-way L2 cache.
> > So it needs only 4 (= 96KB / 8KB / 3) colors.
> >
> > My Alpha box has 4MB direct-map L3 cache and
> > it needs 4MB / 8KB = 512 colors. I have the following entries in my
> > vm_page.h
> >
>
> I am afraid that the current implementation of page coloring doesn't
> scale very well to such a large number of colors, especially if you
> don't have an extremely large amount of physical memory. Far too often,
It could be. Last time I checked, 256 colors gives best user-time
while kernel-build benchmark.
My machine is with 512MB physical memory.
> it's unable to allocate a page of the appropriate color. Even with
> just 8 colors on a machine with 320MB of physical memory, the number
> of times that coloring fails during a "make world" is extraordinary.
How do you detect 'coloring failure'?
By adding counter in vm_page_list_find?
> Bruce Evans and I are looking into this...if someone with an Alpha
> has time to help out that could be useful.
At least, alpha lacks pre-zeroed pages because vm_page_zero_idle is
not enabled...
--
/\ Hidetoshi Shimokawa
\/ simokawa@sat.t.u-tokyo.ac.jp
PGP public key: finger -l simokawa@sat.t.u-tokyo.ac.jp
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