nfsd: eliminate one of the DRC cache searches
authorJeff Layton <jlayton@redhat.com>
Wed, 27 Mar 2013 14:15:37 +0000 (10:15 -0400)
committerJ. Bruce Fields <bfields@redhat.com>
Wed, 3 Apr 2013 15:47:22 +0000 (11:47 -0400)
commit0b9ea37f24e247ed69baabf27fb211aa6a3e7622
tree95f9d8ad7f80cfcb82d175f02e1171537a883e4b
parent64a817cfbded8674f345d1117b117f942a351a69
nfsd: eliminate one of the DRC cache searches

The most common case is to do a search of the cache, followed by an
insert. In the case where we have to allocate an entry off the slab,
then we end up having to redo the search, which is wasteful.

Better optimize the code for the common case by eliminating the initial
search of the cache and always preallocating an entry. In the case of a
cache hit, we'll end up just freeing that entry but that's preferable to
an extra search.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
fs/nfsd/nfscache.c