Re: [PATCH 3/3] hugetlbfs: replace hugetlb_vma_lock with invalidate_lock

From: Mike Kravetz
Date: Mon Sep 25 2023 - 16:07:41 EST


On 09/25/23 15:22, Rik van Riel wrote:
> On Mon, 2023-09-25 at 10:04 +0800, kernel test robot wrote:
> > Hi,
> >
> > kernel test robot noticed the following build errors:
> >
> > [auto build test ERROR on akpm-mm/mm-everything]
> > [also build test ERROR on linus/master v6.6-rc3 next-20230921]
> > [If your patch is applied to the wrong git tree, kindly drop us a
> > note.
> > And when submitting patch, we suggest to use '--base' as documented
> > in
> > https://git-scm.com/docs/git-format-patch#_base_tree_information]
>
> OK, so I have a fix for patch 3/3 that gets rid of the
> compile error, but the libhugetlbfs test cases show that
> patch 3/3 opens up a condition where resv_hugepages
> underflows.
>
> I have not figured out the cause of that yet, but
> patches 1 & 2 seem to survive all tests fine.

In addition, I suspect patch 3 is going to cause a performance regression.
It is taking me a little while to resurrect the test environment used when
the hugetlb vma lock was introduced. My plan is to exercise the series in
that environment.

I should be able to review patches 1 & 2 later (my) today.
--
Mike Kravetz