SUNRPC: Fix a performance regression in the RPC authentication code
commit23918b03060f6e572168fdde1798a905679d2e06
authorTrond Myklebust <Trond.Myklebust@netapp.com>
Thu, 20 Nov 2008 21:06:21 +0000 (20 16:06 -0500)
committerLinus Torvalds <torvalds@linux-foundation.org>
Thu, 20 Nov 2008 21:17:40 +0000 (20 13:17 -0800)
tree4e95edb5030e461a1eb82e2f1fb9cb90a3b46013
parent0cb39aa0ac3a9dc64171b43a85d17e539d82f2d6
SUNRPC: Fix a performance regression in the RPC authentication code

Fix a regression reported by Max Kellermann whereby kernel profiling
showed that his clients were spending 45% of their time in
rpcauth_lookup_credcache.

It turns out that although his processes had identical uid/gid/groups,
generic_match() was failing to detect this, because the task->group_info
pointers were not shared. This again lead to the creation of a huge number
of identical credentials at the RPC layer.

The regression is fixed by comparing the contents of task->group_info
if the actual pointers are not identical.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
net/sunrpc/auth_generic.c