tree 3ca7e8d0047ff03ca532f39b0fc4cd50381e8ecc
parent 87cbc49cd4b773a972bce56c5dd09c4717f3285b
author David Chinner <dgc@sgi.com> 1142303356 +1100
committer Nathan Scott <nathans@sgi.com> 1142303356 +1100

[XFS] using a spinlock per cpu for superblock counter exclusion results in
a preēmpt counter overflow at 256p and above. Change the exclusion
mechanism to use atomic bit operations and busy wait loops to emulate the
spin lock exclusion mechanism but without the preempt count issues.

SGI-PV: 950027
SGI-Modid: xfs-linux-melb:xfs-kern:25338a

Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Nathan Scott <nathans@sgi.com>