Re: [PATCH] updated reiser4 - reduced cpu usage for writes by writingmore than 4k at a time (has implications for generic write code and eventuallyfor the IO layer)

From: Hans Reiser
Date: Wed May 24 2006 - 13:55:02 EST

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Tom Vier wrote:

>On Tue, May 23, 2006 at 01:14:54PM -0700, Hans Reiser wrote:
>
>
>>underlying FS can be improved. Performance results show that the new
>>code consumes 40% less CPU when doing "dd bs=1MB ....." (your hardware,
>>and whether the data is in cache, may vary this result). Note that this
>>has only a small effect on elapsed time for most hardware.
>>
>>
>
>Write requests in linux are restricted to one page?
>
>
>
It may go to the kernel as a 64MB write, but VFS sends it to the FS as
64MB/4k separate 4k writes.
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