Re: [PATCH v2 1/9] mm: vmalloc: Add va_alloc() helper

Uladzislau Rezki
2023-09-06T15:06:32Z

On Wed, Sep 06, 2023 at 01:51:03PM +0800, Baoquan He wrote:
> On 08/29/23 at 10:11am, Uladzislau Rezki (Sony) wrote:
> > Currently __alloc_vmap_area() function contains an open codded
> > logic that finds and adjusts a VA based on allocation request.
> >
> > Introduce a va_alloc() helper that adjusts found VA only. It
> > will be used later at least in two places.
> >
> > There is no a functional change as a result of this patch.
> >
> > Reviewed-by: Christoph Hellwig <hch@lst.de>
> > Reviewed-by: Lorenzo Stoakes <lstoakes@gmail.com>
> > Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
> > ---
> > mm/vmalloc.c | 41 ++++++++++++++++++++++++++++-------------
> > 1 file changed, 28 insertions(+), 13 deletions(-)
> >
> > diff --git a/mm/vmalloc.c b/mm/vmalloc.c
> > index 93cf99aba335..00afc1ee4756 100644
> > --- a/mm/vmalloc.c
> > +++ b/mm/vmalloc.c
> > @@ -1481,6 +1481,32 @@ adjust_va_to_fit_type(struct rb_root *root, struct list_head *head,
> > return 0;
> > }
> >
> > +static unsigned long
> > +va_alloc(struct vmap_area *va,
> > + struct rb_root *root, struct list_head *head,
> > + unsigned long size, unsigned long align,
> > + unsigned long vstart, unsigned long vend)
> > +{
> > + unsigned long nva_start_addr;
> > + int ret;
> > +
> > + if (va->va_start > vstart)
> > + nva_start_addr = ALIGN(va->va_start, align);
> > + else
> > + nva_start_addr = ALIGN(vstart, align);
> > +
> > + /* Check the "vend" restriction. */
> > + if (nva_start_addr + size > vend)
> > + return vend;
> > +
> > + /* Update the free vmap_area. */
> > + ret = adjust_va_to_fit_type(root, head, va, nva_start_addr, size);
> > + if (WARN_ON_ONCE(ret))
> > + return vend;
> > +
> > + return nva_start_addr;
> > +}
> > +
> > /*
> > * Returns a start address of the newly allocated area, if success.
> > * Otherwise a vend is returned that indicates failure.
> > @@ -1493,7 +1519,6 @@ __alloc_vmap_area(struct rb_root *root, struct list_head *head,
> > bool adjust_search_size = true;
> > unsigned long nva_start_addr;
> > struct vmap_area *va;
> > - int ret;
> >
> > /*
> > * Do not adjust when:
> > @@ -1511,18 +1536,8 @@ __alloc_vmap_area(struct rb_root *root, struct list_head *head,
> > if (unlikely(!va))
> > return vend;
> >
> > - if (va->va_start > vstart)
> > - nva_start_addr = ALIGN(va->va_start, align);
> > - else
> > - nva_start_addr = ALIGN(vstart, align);
> > -
> > - /* Check the "vend" restriction. */
> > - if (nva_start_addr + size > vend)
> > - return vend;
> > -
> > - /* Update the free vmap_area. */
> > - ret = adjust_va_to_fit_type(root, head, va, nva_start_addr, size);
> > - if (WARN_ON_ONCE(ret))
> > + nva_start_addr = va_alloc(va, root, head, size, align, vstart, vend);
> > + if (nva_start_addr == vend)
> > return vend;
> >
> > #if DEBUG_AUGMENT_LOWEST_MATCH_CHECK
> > --
> > 2.30.2
>
> Reviewed-by: Baoquan He <bhe@redhat.com>
>
Thanks, i picked it for V3.

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Uladzislau Rezki