On Thu, 2014-06-12 at 12:37 -0700, Davidlohr Bueso wrote: > On Wed, 2014-06-11 at 11:37 -0700, Jason Low wrote: > > Upon entering the slowpath in __mutex_lock_common(), we try once more to > > acquire the mutex. We only try to acquire if (lock->count >= 0). However, > > what we actually want here is to try to acquire if the mutex is unlocked > > (lock->count == 1). > > > > This patch changes it so that we only try-acquire the mutex upon entering > > the slowpath if it is unlocked, rather than if the lock count is > > non-negative. > > This helps further reduce unnecessary atomic xchg() operations. > > > > Furthermore, this patch uses !mutex_is_locked(lock) to do the initial > > checks for if the lock is free rather than directly calling atomic_read() > > on the lock->count, in order to improve readability. > > I think this patch can be merged in 2/4, like you had in v1. Otherwise > looks good.
Ah, I was thinking that removing the macro would be considered a separate change whereas this 3/4 patch was more of an "optimization". But yes, those 2 patches could also have been kept as 1 patch as well. Thanks for the reviews David and Waiman. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/