This fixes a long-standing latency bug in the powerpc qspinlock
implementation that quite a few people have reported and helped
out with debugging.
The first patch is a minimal fix that avoids the problem. The
other patches are streamlining and improvements after the fix.
Thanks,
Nick
Nicholas Piggin (6):
powerpc/qspinlock: Fix stale propagated yield_cpu
powerpc/qspinlock: stop queued waiters trying to set lock sleepy
powerpc/qspinlock: propagate owner preemptedness rather than CPU
number
powerpc/qspinlock: don't propagate the not-sleepy state
powerpc/qspinlock: Propagate sleepy if previous waiter is preempted
powerpc/qspinlock: Rename yield_propagate_owner tunable
arch/powerpc/lib/qspinlock.c | 119 +++++++++++++++--------------------
1 file changed, 52 insertions(+), 67 deletions(-)
--
2.42.0
