On Mon, 2018-04-09 at 11:37 +0200, Christoph Hellwig wrote: > This looks sensible, but I'm worried about taking a whole spinlock > for every request completion, including irq disabling. However it seems > like your new updated pattern would fit use of cmpxchg() very nicely.
Hello Christoph, Thanks for the review. I had a look at the spin lock implementation on x86 and apparently on x86 spin locks are implemented as qspinlocks (include/asm-generic/qspinlock.h). queued_spin_lock() already uses atomic_cmpxchg_acquire(). Are you sure that replacing the spin lock by cmpxchg() will yield a performance improvement? Thanks, Bart.
