Messages in this thread | | | Date | Wed, 22 Oct 2008 13:56:17 -0400 | Subject | Re: High load in 2.6.27, NFS / rpcauth_lookup_credcache()? | From | "J. Bruce Fields" <> |
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On Wed, Oct 22, 2008 at 11:12:08AM +0200, Max Kellermann wrote: > Hi, > > after I was able to fix http://lkml.org/lkml/2008/10/17/147, the > server which was already upgraded to 2.6.27.2 still gets very high > load. It is a web server with NFS file storage (NetApp), and while > the others in the cluster (kernel 2.6.25) have a load of 1-3, 2.6.27.2 > gets 30-50. > > I did an oprofile, with the following results (server just started, > load "only" 5-10):
Well, there's only 7 patches to net/sunrpc/auth.c between 2.6.25 and today, so worst case a 'git bisect v2.6.25..v2.6.27 net/sunrpc/auth.c' might not be too bad.
No particular idea why rpcauth_lookup_credcache would be a problem, though.
--b.
> > 87593 56.1116 (no location information) vmlinux > vmlinux rpcauth_lookup_credcache > 16037 10.2732 auth_generic.c:0 vmlinux > vmlinux generic_match > 6460 4.1382 (no location information) php4 > php4 (no symbols) > 2478 1.5874 (no location information) libc-2.7.so > libc-2.7.so (no symbols) > [...] > > We havn't configured any special authentication method. It is a NFSv3 > over UDP mount, but the kernel has NFSv4 and therefore KRB5 enabled. > > Any ideas why rpcauth_lookup_credcache() goes overboard with CPU > usage? > > Max
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