On Tue, Jun 5, 2012 at 3:09 PM, Peter Grandi <pg@xxxxxxxxxxxxxxxxxxxx> wrote: > [ ... ] > >>> Good call. But the resync is done before the mkfs.xfs is finished, so >>> the time of the copying is not affected by resync. >>> >>> I re-tested with --assume-clean and as expected it has no impact. > >> Wanna try CONFIG_MULTICORE_RAID456? :-) > > That would be intreresting, but the original post reports over > 6GB/s for pure checksumming, and around 400MB/s actual transfer > rate. In theory there is no need here for multihreading. There > may something else going on :-). I have the feeling that some of you have not experienced md0_raid6 taking up 100% CPU of a single core. If you have not, please run the test on http://oletange.blogspot.dk/2012/05/software-raid-performance-on-24-disks.html The test requires 10 GB RAM, atleast 2 CPU cores, and takes less than 3 minutes to run. See if you can reproduce the CPU usage, and post your results along with the reported checksumming speed reported by the kernel. /Ole -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
