Messages in this thread Patch in this message | | | Date | Mon, 31 Aug 2009 22:39:20 +0200 | From | Yohan <> | Subject | Re: VM issue causing high CPU loads |
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Yohan wrote: > Andrew Morton wrote: >> On Mon, 24 Aug 2009 16:23:22 +0200 >> Yohan <kernel@yohan.staff.proxad.net> wrote: >>> Hi, >>> >>> Is someone have an idea for that : >>> >>> http://bugzilla.kernel.org/show_bug.cgi?id=14024 >>> >> Please generate a kernel profile to work out where all the CPU tie is >> being spent. Documentation/basic_profiling.txt is a starting point. >> > I post some new reports, it seems that the problem is in > rpcauth_lookup_credcache ... > > for information, this is an imap mail server that mounts ~10 netapp > over ~300 mountpoints.. I saw that : http://patchwork.kernel.org/patch/24747/
I did only:
--- linux-2.6.27.21/include/linux/sunrpc/auth.h 2009-03-23 23:04:09.000000000 +0100 +++ linux-2.6.27.21/include/linux/sunrpc/auth.h 2009-05-19 16:02:35.000000000 +0200 @@ -62,8 +62,12 @@ */ - #define RPC_CREDCACHE_HASHBITS 4 + #define RPC_CREDCACHE_HASHBITS 12
And i test it in prod since sunday: i only have 36% of one core used by system versus more than 3 cores used by system in another server that did a drop_caches at morning...
Yohan
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