On Fri, Sep 27, 2019 at 5:59 PM Jens Axboe <axboe@xxxxxxxxx> wrote:
>
> On 9/27/19 10:02 AM, Ming Lei wrote:
> > Hi Jens,
> >
> > Looks fio's 'iodepth_batch_submit' is broken.
> >
> > When running the attached fio script[1], I observed that 'nr' passed to
> > io_submit() is 1, except that 64 is only passed to the 1st io_submit().
> >
> > Then plug merging can't work at all.
> >
> > [root@ktest-08 tools]# cat bpf
> > #include <uapi/linux/aio_abi.h>
> > tracepoint:syscalls:sys_enter_io_submit { @nr = hist(args->nr); }
> > [root@ktest-08 tools]# bpftrace ./bpf
> > Attaching 1 probe...
> > ^C
> >
> > @nr:
> > [1] 902349 |@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@|
> > [2, 4) 0 | |
> > [4, 8) 0 | |
> > [8, 16) 0 | |
> > [16, 32) 0 | |
> > [32, 64) 0 | |
> > [64, 128) 1 | |
> >
> > [1] fio script:
> > fio --readwrite=write --filesize=4g --filename=/dev/sda \
> > --runtime=10s --time_based \
> > --ioengine=libaio --direct=1 --bs=4k --iodepth=64 \
> > --iodepth_batch_submit=64 \
> > --numjobs=64 \
> > --name=foo
>
> Try adding iodepth_batch_complete as well.
Yeah, it works, thanks!
--
Ming Lei
