On Wed, Aug 27, 2014 at 08:08:59PM +0400, Maxim Patlasov wrote: ... > 1) /dev/loop0 of 3.17.0-rc1 with Ming's patches applied -- 11K iops > 2) the same as above, but call loop_queue_work() directly from > loop_queue_rq() -- 270K iops > 3) /dev/nullb0 of 3.17.0-rc1 -- 380K iops > > Taking into account so big difference (11K vs. 270K), would it be worthy > to implement pure non-blocking version of aio_kernel_submit() returning > error if blocking needed? Then loop driver (or any other in-kernel user) > might firstly try that non-blocking submit as fast-path, and, only if > it's failed, fall back to queueing. What filesystem is the backing file for loop0 on? O_DIRECT access as Ming's patches use should be non-blocking, and if not, that's something to fix. -ben -- "Thought is the essence of where you are now." -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
