Re: Getting big areas of memory, in 2.3.x?

[Alan Cox <alan@lxorguk.ukuu.org.uk>]

>     Then too, there is the matter of TLB misses for applications which
> visit a lot of data, especially on processors with reasonably large
> caches.  With 4 KB pages and 64 TLB entries, the TLB cannot map all of
> a cache larger than 256 KB.  If the cache is, say, 2 MB and the
> application cycles through many of the pages in the cache in a loop,
> you can wind up with a TLB miss for almost every load (other than those from
> the stack).  With 1 MB pages, there are almost no TLB misses.

With very large amounts of memory I don't doubt this. X86 is alas crippled
with a choice of 4K, 2Mb or 4Mb pages.

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