Re: Re: [PATCH] vhost: Fix typos in comments and clarity on alignof usage

[Simon Horman]

On Wed, Jun 18, 2025 at 01:31:09AM +0530, ALOK TIWARI wrote:
> 
> 
> Thanks Simon,
> 
> On 6/18/2025 12:07 AM, Simon Horman wrote:
> > On Sun, Jun 15, 2025 at 10:39:11AM -0700, Alok Tiwari wrote:
> > > This patch fixes multiple typos and improves comment clarity across
> > > vhost.c.
> > > - Correct spelling errors: "thead" -> "thread", "RUNNUNG" -> "RUNNING"
> > >    and "available".
> > > - Improve comment by replacing informal comment ("Supersize me!")
> > >    with a clear description.
> > > - Use __alignof__ correctly on dereferenced pointer types for better
> > >    readability and alignment with kernel documentation.
> > Could you expand on the last point?
> > I see that the patch uses __alignof__ with rather than without parentheses.
> > But I don't follow how that corresponds with the comment above.
> 
> only I can say "__alignof__ *vq->avail" is valid C,
> but it can hard to read and easy to misinterpret.
> Without proper parentheses sometime, __alignof__ *vq->avail can be
> misleading to reader. it may not be immediately clear whether it refers to
> alignment of the pointer vq->avail or
> alignment of the object it points to.
> __alignof__(*vq->avail) adds parentheses that clarify the intention
> explicitly.
> I can not see very clear guide line to using parentheses or not for
> __alignof__ in kernel document apart
> from(https://www.kernel.org/doc/html/latest/process/coding-style.html).
> Additionally, I have not been able to locate examples in the kernel code
> where __alignof__ is used without parentheses.

Thanks, I understand now.

Perhaps it's not important, but FWIIW I was confused by "correctly".
And something like this seems a bit clearer to me.

  - Use __alignof__ with parentheses which is in keeping with kernel coding
    style for an __attribute__ and arguably improves readability of what is
    being aligned.

In any case, thanks for your explanation.
This patch now looks good to me.

Reviewed-by: Simon Horman <horms@xxxxxxxxxx>