> There may be a long-term way to fix this at a larger scale, but for now
> resolve the immediate problem by gating our call to
> test_and_set_bit_lock() with one to test_bit(), which is obviously
> implemented without using a store.
I am less sure of this now but am continuing to investigate. How
We've encountered a performance issue when multiple processors stress
{get,put}_mmio_atsd_reg(). These functions contend for mmio_atsd_usage,
an unsigned long used as a bitmask.
The accesses to mmio_atsd_usage are done using test_and_set_bit_lock()
and clear_bit_unlock(). As implemented, both of t
