On 8/26/21 4:51 PM, Jens Axboe wrote: > On 8/26/21 5:49 PM, Bart Van Assche wrote: >> On 8/26/21 11:45 AM, Jens Axboe wrote: >>> Just ran a quick test here, and I go from 3.55M IOPS to 1.23M switching >>> to deadline, of which 37% of the overhead is from dd_dispatch(). >>> >>> With the posted patch applied, it runs at 2.3M IOPS with mq-deadline, >>> which is a lot better. This is on my 3970X test box, so 32 cores, 64 >>> threads. >> >> Hi Jens, >> >> With the script below, queue depth >= 2 and an improved version of >> Zhen's patch I see 970 K IOPS with the mq-deadline scheduler in an >> 8 core VM (i7-4790 CPU). In other words, more IOPS than what Zhen >> reported with fewer CPU cores. Is that good enough? > > That depends, what kind of IOPS are you getting if you revert the > original change? Hi Jens, Here is an overview of the tests I ran so far, all on the same test setup: * No I/O scheduler: about 5630 K IOPS. * Kernel v5.11 + mq-deadline: about 1100 K IOPS. * block-for-next + mq-deadline: about 760 K IOPS. * block-for-next with improved mq-deadline performance: about 970 K IOPS. Bart.
