Re: [PATCH v7 00/70] Introducing the Maple Tree

Liam Howlett
2022-04-14T17:17:14Z

* Yu Zhao <yuzhao@google.com> [220414 12:57]:
> On Thu, Apr 14, 2022 at 7:57 AM Liam Howlett <liam.howlett@oracle.com> wrote:
> >
> > * Andrew Morton <akpm@linux-foundation.org> [220414 02:51]:
> > > On Mon, 4 Apr 2022 14:35:26 +0000 Liam Howlett <liam.howlett@oracle.com> wrote:
> > >
> > > > Please add this patch set to your branch. They are based on v5.18-rc1.
> > >
> > > Do we get a nice [0/n] cover letter telling us all about this?
> > >
> > > I have that all merged up and it compiles.
> > >
> > > https://lkml.kernel.org/r/20220402094550.129-1-lipeifeng@oppo.com and
> > > https://lkml.kernel.org/r/20220412081014.399-1-lipeifeng@oppo.com are
> > > disabled for now.
> > >
> > >
> > > Several patches were marked
> > >
> > > From: Liam
> > > Signed-off-by: Matthew
> > > Signed-off-by: Liam
> > >
> > > Which makes me wonder whether the attribution was correct. Please
> > > double-check.
> >
> > I'll have a look, thanks.
> >
> > >
> > >
> > >
> > > I made a lame attempt to fix up mglru's get_next_vma(), and it probably
> > > wants a revisit in the maple-tree world anyway. Please check this and
> > > send me a better version ;)
> >
> > What you have below will function, but there is probably a more maple
> > way of doing things. Happy to help get the sap flowing - it is that
> > time of the year after all ;)
>
> Thanks. Please let me know when the more maple way is ready. I'll test with it.
>
> Also I noticed, for the end address to walk_page_range(), Matthew used
> -1 and you used ULONG_MAX in the maple branch; Andrew used TASK_SIZE
> below. Having a single value throughout would be great.

I think ULONG_MAX would be best, we should probably change the below to
ULONG_MAX.

I don't see the code below in mglru-mapletree (62dd11ea8d). Am I on the
right branch/commit?

>
> > > --- a/mm/vmscan.c~mglru-vs-maple-tree
> > > +++ a/mm/vmscan.c
> > > @@ -3704,7 +3704,7 @@ static bool get_next_vma(struct mm_walk
> > >
> > > while (walk->vma) {
> > > if (next >= walk->vma->vm_end) {
> > > - walk->vma = walk->vma->vm_next;
> > > + walk->vma = find_vma(walk->mm, walk->vma->vm_end);
> > > continue;
> > > }
> > >
> > > @@ -3712,7 +3712,7 @@ static bool get_next_vma(struct mm_walk
> > > return false;
> > >
> > > if (should_skip_vma(walk->vma->vm_start, walk->vma->vm_end, walk)) {
> > > - walk->vma = walk->vma->vm_next;
> > > + walk->vma = find_vma(walk->mm, walk->vma->vm_end);
> > > continue;
> > > }
> > >
> > > @@ -4062,7 +4062,7 @@ static void walk_mm(struct lruvec *lruve
> > > /* the caller might be holding the lock for write */
> > > if (mmap_read_trylock(mm)) {
> > > unsigned long start = walk->next_addr;
> > > - unsigned long end = mm->highest_vm_end;
> > > + unsigned long end = TASK_SIZE;
> > >
> > > err = walk_page_range(mm, start, end, &mm_walk_ops, walk);