Re: [PATCH blktests] common/xfs: ignore the 32M log size during mkfs.xfs

Shinichiro Kawasaki
2022-10-24T00:50:13Z

On Oct 23, 2022 / 23:27, Yi Zhang wrote:
> On Sat, Oct 22, 2022 at 7:57 AM Shinichiro Kawasaki
> <shinichiro.kawasaki@wdc.com> wrote:
> >
> > On Oct 21, 2022 / 21:42, Chaitanya Kulkarni wrote:
> >
> > ...
> >
> > > I think creating a minimal setup is a part of the testcase and we should
> > > not change it, unless there is a explicit reason for doing so.
> >
> > I see, I find no reason to change the "minimal log size policy". Let's go with
> > 64MB log size to keep it.
> >
> > Yi, would you mind reposting v2 with size=64m?
> Sure, and before I post it, I want to ask for suggestions about some
> other code changes:
>
> After set log size with 64M, I found nvme/012 nvme/013 will be
> failed[1], and there was not enough space for fio with size=950m
> testing.
> Either [2] or [3] works, which one do you prefer, or do you have some
> other suggestion for it? Thanks.

Thank you for testing. I guess fio I/O size=950m was chosen subtracting some
super block and log size from 1GB NVME device size. Now we increase the log
size, then the I/O size 950m is larger than the usable xfs size, probably.

Chaitania, what' your thought about the fix approach? To keep the "minimal log
size policy", I guess the approach [3] to reduce fio I/O size to 900m is more
appropriate, but would like to hear your insight.

From Yi's observation, I found a couple of improvement opportunities which are
beyond scope of this fix. Here I note them as memorandum (patches are welcome :)

1) Assuming nvme device size 1GB define in nvme/012 and nvme/013 has relation to
the fio I/O size 950m defined in common/xfs, these values should be defined
at single place. Probably we should define both in nvme/012 and nvme/013.

2) The fio I/O size 950m is defined in _xfs_run_fio_verify_io() which is called
from nvme/035. Then, it is implicitly assumed that TEST_DEV for nvme/035 has
size 1GB (or larger). I found that nvme/035 fails with 512MB nvme device.
We should fix this by calculating fio I/O size from TEST_DEV size. (Or
require 1GB nvme device size for the test case.)

--
Shin'ichiro Kawasaki