Re: [PATCH 2/9] mm: vmalloc: Rename adjust_va_to_fit_type() function

Uladzislau Rezki
2023-05-24T11:51:37Z

On Tue, May 23, 2023 at 01:24:09PM -0400, Liam R. Howlett wrote:
> * Uladzislau Rezki (Sony) <urezki@gmail.com> [230522 07:09]:
> > This patch renames the adjust_va_to_fit_type() function
> > to a shorter variant and more expressive. A new name is
> > va_clip().
> >
> > There is no a functional change as a result of this patch.
> >
> > Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
> > ---
> > mm/vmalloc.c | 13 ++++++-------
> > 1 file changed, 6 insertions(+), 7 deletions(-)
> >
> > diff --git a/mm/vmalloc.c b/mm/vmalloc.c
> > index 409285b68a67..5f900efec6a9 100644
> > --- a/mm/vmalloc.c
> > +++ b/mm/vmalloc.c
> > @@ -1383,9 +1383,9 @@ classify_va_fit_type(struct vmap_area *va,
> > }
> >
> > static __always_inline int
> > -adjust_va_to_fit_type(struct rb_root *root, struct list_head *head,
> > - struct vmap_area *va, unsigned long nva_start_addr,
> > - unsigned long size)
> > +va_clip(struct rb_root *root, struct list_head *head,
> > + struct vmap_area *va, unsigned long nva_start_addr,
> > + unsigned long size)
> > {
> > struct vmap_area *lva = NULL;
> > enum fit_type type = classify_va_fit_type(va, nva_start_addr, size);
> > @@ -1501,7 +1501,7 @@ va_alloc(struct vmap_area *va,
> > return vend;
> >
> > /* Update the free vmap_area. */
> > - ret = adjust_va_to_fit_type(root, head, va, nva_start_addr, size);
> > + ret = va_clip(root, head, va, nva_start_addr, size);
> > if (WARN_ON_ONCE(ret))
>
> ret is only used in this WARN_ON_ONCE() check (from patch 1), since you
> have shortened adjust_va_to_fit_type(), you can probably drop the ret
> variable all together here?
>
I can move the WARN_ON_ONCE() check into the va_clip(). So it makes sense.

As for a return value, we should check it, at least here:

ret = va_clip(&free_vmap_area_root,
&free_vmap_area_list, va, start, size);
if (WARN_ON_ONCE(unlikely(ret)))
/* It is a BUG(), but trigger recovery instead. */
goto recovery;

i t can fail, though it rather goes toward almost zero%.

Thank you for looking at it, Liam!

--
Uladzuslau Rezki