On Mon, Aug 10, 2015 at 01:23:48PM -0400, Jeff Moyer wrote: > Unfortunately, I'm unable to reproduce your results (though my test > setup uses SAS disks, not SATA). I tried with a 10 data disk md RAID5, > with 32k and 128k chunk sizes. I modified the fio program to read/write > multiples of the stripe width, and I also used aio-stress over a range > of queue depth and I/O sizes for read, write, random read and random > write. I didn't see any measurable performance difference. Do you > still have access to your test setup?
Unfortuntately I don't have access to a large RAID setup at the moment. > What do you think about reinstituting the artificial max_sectors_kb cap, > but bumping the default up from 512KB to 1280KB? I had our performance > team run numbers on their test setup (which is a 12 disk raid0 with 32k > chunk size, fwiw) with max_sectors_kb set to 1280 and, aside from one > odd data point, things looked good. Let's settle on that for 4.2 and then look it in more detail. > > Cheers, > Jeff ---end quoted text--- -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
