Re: [PATCH v2 03/13] filemap: align the index to mapping_min_order in the page cache

["Pankaj Raghav (Samsung)" <kernel@pankajraghav.com>]

On Fri, Mar 01, 2024 at 03:04:33PM -0500, Kent Overstreet wrote:
> On Fri, Mar 01, 2024 at 07:26:55PM +0000, Matthew Wilcox wrote:
> > On Fri, Mar 01, 2024 at 05:44:34PM +0100, Pankaj Raghav (Samsung) wrote:
> > > +#define DEFINE_READAHEAD_ALIGNED(ractl, f, r, m, i)			\
> > > +	struct readahead_control ractl = {				\
> > > +		.file = f,						\
> > > +		.mapping = m,						\
> > > +		.ra = r,						\
> > > +		._index = mapping_align_start_index(m, i),		\
> > > +	}
> > 
> > My point was that you didn't need to do any of this.
> > 
> > Look, I've tried to give constructive review, but I feel like I'm going
> > to have to be blunt.  There is no evidence of design or understanding
> > in these patches or their commit messages.  You don't have a coherent
> > message about "These things have to be aligned; these things can be at
> > arbitrary alignment".  If you have thought about it, it doesn't show.
> 
> Don't you think you might be going off a bit much? I looked over these
> patches after we talked privately, and they looked pretty sensible to
> me...
> 
> Yes, we _always_ want more thorough commit messages that properly
> explain the motivations for changes, but in my experience that's the
> thing that takes the longest to learn how to do well as an engineer...
> ease up abit.
> 
> > So, let's start off: Is the index in ractl aligned or not, and why do
> > you believe that's the right approach?  And review each of the patches
> > in this series with the answer to that question in mind because you are
> > currently inconsistent.
> 
> ^ this is a real point though, DEFINE_READAHEAD_ALIGNED() feels off to
> me.

Thanks Kent. I am going over the patches again and changing it based on
the feedback.