On 2018-11-07 3:57 p.m., Jens Axboe wrote: > On 11/5/18 8:00 AM, Sebastien Boisvert wrote: >> >> >> On 2018-11-04 5:44 a.m., Sitsofe Wheeler wrote: >>> Looks like someone is referencing an fio benchmark result on Apple's >>> Mac Mini page and whoever did it took care to respect the Moral >>> License (https://fio.readthedocs.io/en/latest/fio_doc.html#moral-license >>> ). From https://www.apple.com/mac-mini/ : >>> >>> "4. Testing conducted by Apple in October 2018 using preproduction >>> 3.2GHz 6-core Intel Core i7-based Mac mini systems with 64GB of RAM >>> and 1TB SSD, and shipping 3.0GHz dual-core Intel Core i7-based Mac >>> mini systems with 16GB of RAM and 1TB SSD. Tested with FIO 3.8, 1024KB >>> request size, 150GB test file and IO depth=8. Performance tests are >>> conducted using specific computer systems and reflect the approximate >>> performance of Mac mini." >>> >>> My only question is: as the depth was 8 were they using the posixaio engine? >>> >> >> The foot note number 4 supports this claim: >> >> "Up to 4X faster read speed" >> >> It would make sense to use asynchronous I/O since ioengine=psync is the default on Mac. > > I'd be fine making that change, if someone can benchmark psync vs posixaio > in terms of latency in that platform. > > Might also make sense to improve the setup so that we have a default > engine per OS depending on iodepth. For instance, on Linux, QD=1 should > just be psync. But if QD > 1, then we should default to libaio. I'm > afraid lots of folks have run iodepth=32 or whatever without changing > the IO engine and wondering what is going on. Would this change be *after* parse_options() has been called ? I looked at init.c and options.{h,c}. Thanks. > > If someone would like to work on that... There might be cookies as > a bonus. >
