Re: [PATCH v5 6/7] selftests: mm: Add a test for remapping within a range

[Joel Fernandes <joel@joelfernandes.org>]

On Mon, Aug 28, 2023 at 08:38:17PM +0100, Lorenzo Stoakes wrote:
> On Mon, Aug 28, 2023 at 06:59:12PM +0000, Joel Fernandes wrote:
> > On Sun, Aug 27, 2023 at 11:15:20AM +0100, Lorenzo Stoakes wrote:
> > > On Sun, Aug 27, 2023 at 10:57:59AM +0100, Lorenzo Stoakes wrote:
> > > [snip]
> > >
> > > > > +/*
> > > > > + * Verify that an mremap within a range does not cause corruption
> > > > > + * of unrelated part of range.
> > > > > + *
> > > > > + * Consider the following range which is 2MB aligned and is
> > > > > + * a part of a larger 10MB range which is not shown. Each
> > > > > + * character is 256KB below making the source and destination
> > >
> > > Just noticed, I think you misspeak here, as this test doens't seem to
> > > offset by 256 KiB? That is the strategy for mremap_move_1mb_from_start()
> > > rather than this test so perhaps comment needs to be moved around?
> > >
> > >  * 2MB each. The lower case letters are moved (s to d) and the
> > >  * upper case letters are not moved. The below test verifies
> > >  * that the upper case S letters are not corrupted by the
> > >  * adjacent mremap.
> > >  *
> > >  * |DDDDddddSSSSssss|
> > >  */
> > >  static void mremap_move_within_range(char pattern_seed)
> >
> > Here we are moving 1MB within a 4MB zone of a large mapping. Each character
> > 's' or 'd' is 256KB. The 256KB there is just for illustration and not really
> > significant as such. The 'ssss' is moved to 'dddd' 1MB each. Here we make
> 
> Ahhh I see. I find that a little confusing here, perhaps clearer to say 'each
> block of letters is 1 MiB in size' or something?

Sure, I'll do that.
 
> Cheers!

Cheers. And thanks for the reviews!

 - Joel