Re: [PATCH 01/12] generic/757: fix various bugs in this test

Darrick J. Wong
2024-11-21T17:19:24Z

On Thu, Nov 21, 2024 at 08:33:55AM -0800, Darrick J. Wong wrote:
> On Thu, Nov 21, 2024 at 11:52:48AM +0100, Christoph Hellwig wrote:
> > On Thu, Nov 21, 2024 at 11:13:25AM +0100, Christoph Hellwig wrote:
> > > proper zeroout ioctl, which fixes my generic/757 issues, and should
> >
> > It turns out then when I extrapolate my shortened 10 iteration run
> > to the 100 currently in the test it would take ~ 30 minutes. I'm
> > not sure that's really a reasonable run time for a single test in
> > the auto group.
>
> Yeah, perhaps I should adjust this one to use TIME_FACTOR too?
>
> while _soak_loop_running $((10 * TIME_FACTOR)); do
> # timeconsuming stuff
> done
>
> (and then you can SOAK_DURATION=10s to limit the runtime)

Oh, that's with your BLKDISCARD -> BLKZEROOUT change applied, isn't it?
On my system, 100 loops takes 96 seconds with discard and 639 seconds
with zeroout.

So yes, we should shift this test to use thinp. I was going to say that
we should also make _log_writes_init skip the test if the block device
has discard_zeroes_data==0, but apparently it's now hardwired to zero
and (AFAICT) there's no way to tell if unmap actually zeroes even for
software defined devices like thinp where we *know* that works. :(

--D