On Mon, 18 Feb 2008 16:12:38 +0800, "Zhang, Yanmin" said: > I also think __refcnt is the key. I did a new testing by adding 2 unsigned > long > pading before lastuse, so the 3 members are moved to next cache line. The > performance is > recovered. > > How about below patch? Almost all performance is recovered with the new patch. > > Signed-off-by: Zhang Yanmin <[EMAIL PROTECTED]>
Could you add a comment someplace that says "refcnt wants to be on a different cache line from input/output/ops or performance tanks badly", to warn some future kernel hacker who starts adding new fields to the structure?
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