Hi Andi, On 25/03/13 11:32, Andi Kleen wrote: > Christian Schmidt <schmidt@xxxxxxxxx> writes: >> >> Is there a way I can make the scheduler put those on multiple cores? > > Submit the IO from multiple cores. Don't use dd. The dd processes run on multiple cores. I do understand that you were saying "multiple requests to the same device from multiple cores", however I only see kworkers from core 0 active, even with corelocked dd processes (via numactl). Since I just skimmed to the pcrypt.c I kind of realized that was the answer - do I understand correctly that the core for the kworker follows the core of the requestor? Basically that means that I can not get the aggregate throughput for all devices higher than that for a single device by changing the stacking, e.g. dm-crypt on top of md-raid / below the md-raid, or below zfs/btrfs vdevs, since all user space requests will always appear to the crypto layer to originate from core 0, irrespective of the core the application runs on, unless the file system runs multithreaded? I just tested this with ZFS, and all kworkers run on core 0 during file I/O or when resilvering a raidZ. I don't have a btrfs managing its own vdevs at hand to compare though. Thanks for your input, Christian _______________________________________________ dm-crypt mailing list dm-crypt@xxxxxxxx http://www.saout.de/mailman/listinfo/dm-crypt
