On Wednesday 20 April 2005 13:52, Linus Torvalds wrote:

On Wed, 20 Apr 2005, Chris Mason wrote:

quoted

The patch below with your current tree brings my 100 patch test down to
22 seconds again.

If you ever have a cache_entry bigger than 16384, your code will write
things out in the wrong order (write the new cache without flushing the
old buffer).

Whoops

Finally, if you really want to go fast, you should really try to make your
writes powers-of-two, ie fill up the buffer entirely rather than saying
"if I were to overflow, flush it now". It doesn't matter that much for
some filesystems (especially local and append-only like the patterns are
here), but it can definitely matter for the stupid ones.

Well, the difference there should be pretty hard to see with any benchmark.
But I was being lazy...new patch attached.  This one gets the same perf 
numbers, if this is still wrong then I really need some more coffee.

-chris