On Wed, Dec 07, 2022 at 11:17:12PM +0000, Chaitanya Kulkarni wrote: > On 12/7/22 15:08, Jens Axboe wrote: > > > > My default peak testing runs at 122M IOPS. That's also the peak IOPS of > > the devices combined, and with iostats disabled. If I enabled iostats, > > then the performance drops to 112M IOPS. It's no longer device limited, > > that's a drop of about 8.2%. > > > > Wow, clearly not acceptable that's exactly I asked for perf > numbers :). For the record, we did say per-io ktime_get() has a measurable performance harm and should be aggregated. https://www.spinics.net/lists/linux-block/msg89937.html