Re: [PATCH 0/3] zram: Replace pr_* with dev_*

Sergey Senozhatsky
2015-08-07T06:37:24Z

Hello Minchan,

On (08/07/15 15:05), Minchan Kim wrote:
[..]
> > I'd prefer to leave the messages the way they are. Changing anything
> > visible to user space (api, eror codes, error messages, etc.) is a
> > very risky business. You change the format of error messages and it
> > smells like a big NO-NO.
> >
> > 'zram: Cannot initialise lzo compressing backend'
> > --> 'block zram0: Cannot initialise lzo compressing backend'
> >
> >
> > And there are even more dramatic changes:
> > "Cannot change max compression streams\n"
> > --> "Cannot change max compression streams to %d\n"
> >
> > "Can't change algorithm for initialized device\n"
> > --> "Can't change algorithm to %s for initialized device\n"
> >
> >
> > People already can have scripts doing `grep "zram:"` on dmesg or
> > whatever. We cannot change this anymore.
> >
> > This potentially breaks things in user space. So, I NACK the change
> > set. Thanks.
> >
> > Minchan, any opinion?
>
> Note: I didn't read this patchset in detail so I might be wrong.
>
> When I read description, I couldn't see what's the benefit.
> Please write it out.

we now have errors like
'zram: Cannot initialise lzo compressing backend'

and they will transform into

'block zram0: Cannot initialise lzo compressing backend'

note the prefix 'zram:' became 'block zram0:'

and there are two patches (well, at least I quickly spotted only
those) that change messages' text

From: "Cannot change max compression streams\n"
To: "Cannot change max compression streams to %d\n"

where %d is a supplied max_comp_stream value

From: "Can't change algorithm for initialized device\n"
To: "Can't change algorithm to %s for initialized device\n"

where %s is a supplied compression algorithm name.

as far as I can tell.

-ss