Messages in this thread | | | From | "Stephen C. Tweedie" <> | Date | Fri, 30 Apr 1999 00:53:16 +0100 (BST) | Subject | Re: 2.2.5 optimizations for web benchmarks? |
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Hi,
On Mon, 26 Apr 1999 19:08:36 -0400 (EDT), Greg Lindahl <lindahl@cs.virginia.edu> said:
>> If you are sharing the virtual memory space it means you don't take >> a TLB flush
> If I recall correctly, the Sybase folks described this as a major win > across many OSes. On the other hand, Apache in particular may not > access enough memory to make a huge difference.
Remember, this is TLB flushes, not cache flushes, we're talking about. *Every* memory access after a TLB flush needs to reload the TLB, even if it is just a read from already-cached memory. Even just spinning in kernel space may require TLB refills after a flush (although newer Pentia do let you mark certain page tables as global, so a mm replace won't evict those TLBs).
--Stephen
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