[SPARC64]: Implement atomic backoff.
authorDavid S. Miller <davem@sunset.davemloft.net>
Mon, 15 Oct 2007 23:41:44 +0000 (16:41 -0700)
committerDavid S. Miller <davem@sunset.davemloft.net>
Wed, 17 Oct 2007 23:24:55 +0000 (16:24 -0700)
commit24f287e412ae90de8d281543c8b1043b6ed6c019
treeeb69803d187d35fd9e90c1428952c0ed5a0970c1
parentd85714d81cc0408daddb68c10f7fd69eafe7c213
[SPARC64]: Implement atomic backoff.

When the cpu count is high and contention hits an atomic object, the
processors can synchronize such that some cpus continually get knocked
out and cannot complete the atomic update.

So implement an exponential backoff when SMP.

Signed-off-by: David S. Miller <davem@davemloft.net>
arch/sparc64/lib/atomic.S
arch/sparc64/lib/bitops.S
include/asm-sparc64/backoff.h [new file with mode: 0644]