Messages in this thread |  | | | Subject | Re: tbench regression in 2.6.25-rc1 | | From | Valdis.Kletnieks@vt ... | | Date | Mon, 18 Feb 2008 12:33:53 -0500 | |
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 <yanmin.zhang@intel.com>
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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