Messages in this thread | | | Subject | Re: [PATCH] 2.5.14 IDE 56 | From | Andi Kleen <> | Date | 10 May 2002 02:33:19 +0200 |
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Andrew Morton <akpm@zip.com.au> writes:
> For bulk read() and write() I/O the best sized buffer is 8 kbytes. 4k is > pretty good, too. Anything larger blows the user-side buffer out of L1. > This is for x86.
Modern x86 support prefetch hints for the CPU to tell it to not pollute the caches with "streaming data". I bet using them would be a big win. The rep ; movsl loop used in copy*user isn't very good on modern x86 anyways (it is ok on PPro, but loses on Athlon and P4)
I'm (slowly) working on such functions for x86-64, it should be eventually possible to backport them to i386.
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