[LTP] [PATCH] syscalls/utime03: relax the check for 1 second difference

[Jan Stancek]

On Thu, Feb 20, 2025 at 12:17 PM Cyril Hrubis <chrubis@suse.cz> wrote:
>
> Hi!
> > The test is using tst_get_fs_timestamp() which is using REALTIME_COARSE
> > clock, which is slightly less accurate. Back in 2022 we added extra log
> > message to print also min and max time. In those rare instances where
> > it fails this extra log shows it failed by one second difference.
> >
> > Relax the check a little. Tested on aarch64 VMs, where it's usually
> > reproducible after couple hundred iterations.
>
> Aren't we just masking a kernel bug here? Back then we discussed this
> with kernel devs and they told us that filesystems use REALTIME_COARSE
> internally, so this shouldn't really fail.

I see the failures resurfacing around 6.13-rc1.
>From commit 4e40eff0b573 ("fs: add infrastructure for multigrain timestamps")
the comment on current_time() now says "Return FS time (possibly fine-grained)".

Maybe we hit a point where internals changed? I'll see if I can narrow
it down further
with bisect.

>
> What filesystem is this? Does it, by chance, use more granual
> timestamps?

I saw it fail on ext2, ext3 and xfs.

>
> --
> Cyril Hrubis
> chrubis@suse.cz
>