Re: [PATCH] mm/vmalloc.c: Remove always-true conditional in vmap_init_free_space

[Pengfei Li]

On Tue, Jul 9, 2019 at 1:35 AM Matthew Wilcox <willy@xxxxxxxxxxxxx> wrote:
>
> On Tue, Jul 09, 2019 at 01:06:31AM +0800, Pengfei Li wrote:
> > When unsigned long variables are subtracted from one another,
> > the result is always non-negative.
> >
> > The vmap_area_list is sorted by address.
> >
> > So the following two conditions are always true.
> >
> > 1) if (busy->va_start - vmap_start > 0)
> > 2) if (vmap_end - vmap_start > 0)
> >
> > Just remove them.
>
> That condition won't be true if busy->va_start == vmap_start.

Yes, you're right.
Sorry for my bad job.