Re: [PATCH] zbd: remove reset_zone flag from fio_zone_info

[Alexey Dobriyan <adobriyan@gmail.com>]

On Wed, Aug 19, 2020 at 07:35:03PM +0000, Dmitry Fomichev wrote:
> 
> 
> > -----Original Message-----
> > From: Alexey Dobriyan <adobriyan@gmail.com>
> > Sent: Wednesday, August 19, 2020 8:56 AM
> > To: Dmitry Fomichev <Dmitry.Fomichev@wdc.com>
> > Cc: fio@vger.kernel.org
> > Subject: Re: [PATCH] zbd: remove reset_zone flag from fio_zone_info
> > 
> > > The reset_zone flag that is defined in fio_zone_info structure is
> > > only referenced in zbd_adjust_block() function. Convert this flag
> > > to a local variable and save some room in zbd_info array which can
> > > be pretty large when running fio against high capacity zoned devices.
> > 
> > This flag should be kept.
> > 
> > Test can crash or be interrupted leaving hw in indeterminate state,
> > it must be restarted from clean state. Or test can be precondition and
> > zone should not be reset.
> 
> This is beyond the scope of fio. Any preconditioning of zones is done
> by external scripts that have no access to this flag. Tools like blkzone,
> libzbc or nvme-cli are typically used to precondition zones before
> testing and to analyze zone state after test runs.

If it is a matter of policy that fio doesn't do preconditioning,
then the patch is OK.

We do preconditioning in fio, it is neat:
* don't need external programs
* everything inside one job file
* not a lot of code to add

But to do this, flag must live in "struct fio_zone_info".

	[zra]
	zone_reset_all=1
	zone_finish_all=1
	rw=write

	[pre]
	stonewall
	zone_reset_all=0
	zone_finish_all=0
	job_max_open_zones=...
	rw=write
		...

	[j]
	stonewall
	zone_reset_all=0
	zone_finish_all=0
	rw=randread
		...