On Tue, Feb 11, 2014 at 03:23:51PM +0530, Raghavendra KT wrote: > How much important to have holder information for PPC? From my > previous experiment > on x86, it was lock-waiter preemption which is problematic rather than > lock-holder preemption.
It's something very special to IBM pSeries: the hypervisor can assign fractions of physical CPUs to guests. Sometimes a guest with 4 quarter CPUs will be faster than 1 monoprocessor. (correct me if I'm wrong). The directed yield resolves the silly situation when holder and waiter reside on the same physical CPU, as I understand it. x86 has nothing comparable. Torsten -- 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/