Commit graph

3 commits

Author SHA1 Message Date
David S. Miller
4cfea5a7df [SPARC64]: Fix atomic backoff limit.
4096 will not fit into the immediate field of a compare instruction,
in fact it will end up being -4096 causing the check to fail every
time and thus disabling backoff.

Signed-off-by: David S. Miller <davem@davemloft.net>
2008-03-19 01:04:48 -07:00
David S. Miller
0aa031d9e0 [SPARC64]: Fix BACKOFF_SPIN on non-SMP.
It can't be just empty, it has to at least branch
back to 'label'.

Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-27 00:23:22 -07:00
David S. Miller
24f287e412 [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>
2007-10-17 16:24:55 -07:00