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

[Yu Zhao]

On Thu, Apr 14, 2022 at 7:57 AM Liam Howlett <liam.howlett@xxxxxxxxxx> wrote:
>
> * Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> [220414 02:51]:
> > On Mon, 4 Apr 2022 14:35:26 +0000 Liam Howlett <liam.howlett@xxxxxxxxxx> 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@xxxxxxxx and
> > https://lkml.kernel.org/r/20220412081014.399-1-lipeifeng@xxxxxxxx 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.

> > --- 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);