From: "Liam R. Howlett" <[email protected]>
Prepare for the removal of the vma_mas_store() function by open coding
the maple tree store in this test code. Set the range of the maple
state and call the store function directly.
Cc: SeongJae Park <[email protected]>
Cc: [email protected]
Reported-by: kernel test robot <[email protected]>
Signed-off-by: Liam R. Howlett <[email protected]>
---
mm/damon/vaddr-test.h | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/mm/damon/vaddr-test.h b/mm/damon/vaddr-test.h
index bce37c487540..41532f7355d0 100644
--- a/mm/damon/vaddr-test.h
+++ b/mm/damon/vaddr-test.h
@@ -24,8 +24,10 @@ static void __link_vmas(struct maple_tree *mt, struct vm_area_struct *vmas,
return;
mas_lock(&mas);
- for (i = 0; i < nr_vmas; i++)
- vma_mas_store(&vmas[i], &mas);
+ for (i = 0; i < nr_vmas; i++) {
+ mas_set_range(&mas, vmas[i].vm_start, vmas[i].vm_end - 1);
+ mas_store_gfp(&mas, &vmas[i], GFP_KERNEL);
+ }
mas_unlock(&mas);
}
--
2.35.1
Hi Liam,
On Thu, 5 Jan 2023 19:16:00 +0000 Liam Howlett <[email protected]> wrote:
> From: "Liam R. Howlett" <[email protected]>
>
> Prepare for the removal of the vma_mas_store() function by open coding
> the maple tree store in this test code.
But seems this series is not really removing 'vma_mas_store()'. Wouldn't it
better to do the preparation and removal together in a same patch series?
> Set the range of the maple
> state and call the store function directly.
>
> Cc: SeongJae Park <[email protected]>
> Cc: [email protected]
> Reported-by: kernel test robot <[email protected]>
> Signed-off-by: Liam R. Howlett <[email protected]>
> ---
> mm/damon/vaddr-test.h | 6 ++++--
> 1 file changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/mm/damon/vaddr-test.h b/mm/damon/vaddr-test.h
> index bce37c487540..41532f7355d0 100644
> --- a/mm/damon/vaddr-test.h
> +++ b/mm/damon/vaddr-test.h
> @@ -24,8 +24,10 @@ static void __link_vmas(struct maple_tree *mt, struct vm_area_struct *vmas,
> return;
>
> mas_lock(&mas);
> - for (i = 0; i < nr_vmas; i++)
> - vma_mas_store(&vmas[i], &mas);
> + for (i = 0; i < nr_vmas; i++) {
> + mas_set_range(&mas, vmas[i].vm_start, vmas[i].vm_end - 1);
> + mas_store_gfp(&mas, &vmas[i], GFP_KERNEL);
> + }
On the latest mm-unstable, vma_mas_store() uses mas_store_prealloc() instead of
mas_store_gfp(). Seems the difference would make no problem to this test code
in most cases, but could I ask the reason for this change?
Also, should we check the return value of mas_store_gfp()?
> mas_unlock(&mas);
> }
>
> --
> 2.35.1
Thanks,
SJ
* SeongJae Park <[email protected]> [230105 14:33]:
> Hi Liam,
>
> On Thu, 5 Jan 2023 19:16:00 +0000 Liam Howlett <[email protected]> wrote:
>
> > From: "Liam R. Howlett" <[email protected]>
> >
> > Prepare for the removal of the vma_mas_store() function by open coding
> > the maple tree store in this test code.
>
> But seems this series is not really removing 'vma_mas_store()'. Wouldn't it
> better to do the preparation and removal together in a same patch series?
It does from the all code but the nommu side. The definition is dropped
from the header and c file in "mmap: Convert __vma_adjust() to use vma
iterator" [1].
>
> > Set the range of the maple
> > state and call the store function directly.
> >
> > Cc: SeongJae Park <[email protected]>
> > Cc: [email protected]
> > Reported-by: kernel test robot <[email protected]>
> > Signed-off-by: Liam R. Howlett <[email protected]>
> > ---
> > mm/damon/vaddr-test.h | 6 ++++--
> > 1 file changed, 4 insertions(+), 2 deletions(-)
> >
> > diff --git a/mm/damon/vaddr-test.h b/mm/damon/vaddr-test.h
> > index bce37c487540..41532f7355d0 100644
> > --- a/mm/damon/vaddr-test.h
> > +++ b/mm/damon/vaddr-test.h
> > @@ -24,8 +24,10 @@ static void __link_vmas(struct maple_tree *mt, struct vm_area_struct *vmas,
> > return;
> >
> > mas_lock(&mas);
> > - for (i = 0; i < nr_vmas; i++)
> > - vma_mas_store(&vmas[i], &mas);
> > + for (i = 0; i < nr_vmas; i++) {
> > + mas_set_range(&mas, vmas[i].vm_start, vmas[i].vm_end - 1);
> > + mas_store_gfp(&mas, &vmas[i], GFP_KERNEL);
> > + }
>
> On the latest mm-unstable, vma_mas_store() uses mas_store_prealloc() instead of
> mas_store_gfp(). Seems the difference would make no problem to this test code
> in most cases, but could I ask the reason for this change?
mas_store_prealloc() expects the maple state to have the necessary
memory to store the value. Using this function is the right way of
storing the range. In fact, we would only need a single node since
these values will be append operations anyways.
>
> Also, should we check the return value of mas_store_gfp()?
I can add this. The only reason we would return an error is on ENOMEM
which seems unlikely here. Again, it is a single node that will be
used. The size is 256B, but it's safer to add the check.
[1] https://lore.kernel.org/linux-mm/[email protected]/
Thanks,
Liam
Hi Liam,
On Thu, 5 Jan 2023 19:52:21 +0000 Liam Howlett <[email protected]> wrote:
> * SeongJae Park <[email protected]> [230105 14:33]:
> > Hi Liam,
> >
> > On Thu, 5 Jan 2023 19:16:00 +0000 Liam Howlett <[email protected]> wrote:
> >
> > > From: "Liam R. Howlett" <[email protected]>
> > >
> > > Prepare for the removal of the vma_mas_store() function by open coding
> > > the maple tree store in this test code.
> >
> > But seems this series is not really removing 'vma_mas_store()'. Wouldn't it
> > better to do the preparation and removal together in a same patch series?
>
> It does from the all code but the nommu side. The definition is dropped
> from the header and c file in "mmap: Convert __vma_adjust() to use vma
> iterator" [1].
Thank you for nice explanation.
>
> >
> > > Set the range of the maple
> > > state and call the store function directly.
> > >
> > > Cc: SeongJae Park <[email protected]>
> > > Cc: [email protected]
> > > Reported-by: kernel test robot <[email protected]>
> > > Signed-off-by: Liam R. Howlett <[email protected]>
> > > ---
> > > mm/damon/vaddr-test.h | 6 ++++--
> > > 1 file changed, 4 insertions(+), 2 deletions(-)
> > >
> > > diff --git a/mm/damon/vaddr-test.h b/mm/damon/vaddr-test.h
> > > index bce37c487540..41532f7355d0 100644
> > > --- a/mm/damon/vaddr-test.h
> > > +++ b/mm/damon/vaddr-test.h
> > > @@ -24,8 +24,10 @@ static void __link_vmas(struct maple_tree *mt, struct vm_area_struct *vmas,
> > > return;
> > >
> > > mas_lock(&mas);
> > > - for (i = 0; i < nr_vmas; i++)
> > > - vma_mas_store(&vmas[i], &mas);
> > > + for (i = 0; i < nr_vmas; i++) {
> > > + mas_set_range(&mas, vmas[i].vm_start, vmas[i].vm_end - 1);
> > > + mas_store_gfp(&mas, &vmas[i], GFP_KERNEL);
> > > + }
> >
> > On the latest mm-unstable, vma_mas_store() uses mas_store_prealloc() instead of
> > mas_store_gfp(). Seems the difference would make no problem to this test code
> > in most cases, but could I ask the reason for this change?
>
> mas_store_prealloc() expects the maple state to have the necessary
> memory to store the value. Using this function is the right way of
> storing the range. In fact, we would only need a single node since
> these values will be append operations anyways.
Again, thank you for nice explanation.
>
> >
> > Also, should we check the return value of mas_store_gfp()?
>
> I can add this. The only reason we would return an error is on ENOMEM
> which seems unlikely here. Again, it is a single node that will be
> used. The size is 256B, but it's safer to add the check.
You're right. I'd prefer having the check, but I'd not block this for the
trivial nit.
Reviewed-by: SeongJae Park <[email protected]>
Thanks,
SJ
>
> [1] https://lore.kernel.org/linux-mm/[email protected]/
>
>
> Thanks,
> Liam
>