On Tue, Sep 15, 2015 at 11:29:14AM -0400, Waiman Long wrote: > Only the queue head vCPU will be in pv_wait_head() spinning to acquire the > lock.
But what will guarantee fwd progress for the lock that is the head? Suppose CPU0 becomes head and enters the /* claim the lock */ loop. Then CPU1 comes in, steals it in pv_wait_head(). CPU1 releases, CPU1 re-acquires and _again_ steals in pv_wait_head(), etc.. All the while CPU0 doesn't go anywhere. -- 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/
