Re: [PATCH v7 1/1] gpio: add sloppy logic analyzer using polling
From: Andy Shevchenko
Date: Mon Mar 28 2022 - 08:52:24 EST
On Mon, Mar 28, 2022 at 02:19:55PM +0200, Wolfram Sang wrote:
>
> > > I don't like assigning 'priv' memebers twice, so I'd like to keep it as
> > > is.
> >
> > But this will give better understanding of the steps the code performs, no?
>
> IMO the current version is readable :)
OK!
...
> > (Because this function basically contains two steps at once. I assume it's
> > done this way due to absence of vrealloc(), right?)
> >
> > But we have kvrealloc(). Can it be used here?
>
> This has a huge disadvantage: realloc() requests new memory before the
> old one is discarded. If you want to make a huge buffer bigger, this can
> lead to OOM. The old contents do not matter, so the old buffer can go
> away in favor of the new one.
Fair enough.
...
> > > > Can it be wrapped by DEFINE_SHOW_ATTRIBUTE()?
> > >
> > > I don't see a way. Do you?
> >
> > Me neither. I mixed this up with (not upstreamed yet) DEFINE_STORE_ATTRIBUTE.
>
> Still no cigar. That one is for rw files. Mine is writable only, so I use
> e.g. no_llseek.
>
> Probably, the above macro should be named, DEFINE_SHOWSTORE_ATTRIBUTE.
> But I see this macro is stalled since late 2020 anyhow.
Right, not applicable here anyway.
--
With Best Regards,
Andy Shevchenko