On Thu, 12 Feb 2015, Jesper Dangaard Brouer wrote: > Measured on my laptop CPU i7-2620M CPU @ 2.70GHz: > > * 12.775 ns - "clean" spin_lock_unlock > * 21.099 ns - irqsave variant spinlock > * 22.808 ns - "manual" irqsave before spin_lock > * 14.618 ns - "manual" local_irq_disable + spin_lock > > Reproducible via my github repo: > https://github.com/netoptimizer/prototype-kernel/blob/master/kernel/lib/time_bench_sample.c > > The clean spin_lock_unlock is 8.324 ns faster than irqsave variant. > The irqsave variant is actually faster than expected, as the measurement > of an isolated local_irq_save_restore were 13.256 ns. I am using spin_lock_irq() in the current version on my system. If the performance of that is a problem then please optimize that function. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>