I was doing readv with the same tool that i shared earlier: go test ./fs -run=xx -bench=BenchmarkReadAt/os_5 -benchtime=8000000x -cpu=256 On 5.8.3 it is consistently > 100 mb/s, on 5.9-rc2 ~50 mb/s on my device. with uring i was getting > 250 mb/s, and now ~70 mb/s. double checked if there is any difference with writev, and i don't see any. On Tue, 25 Aug 2020 at 16:39, Jens Axboe <axboe@xxxxxxxxx> wrote: > > On 8/25/20 2:52 AM, Dmitry Shulyak wrote: > > this patch fixes the issue with 0 reads. there seems to be a > > regression that is not specific to uring, > > regular syscall reads slowed down noticeably. > > Do you have a test case? Related to specific system calls, or just > overall? My initial suspicion would be Yet Another one of the > security fixes... > > -- > Jens Axboe >
