On Wed, 28 Apr 2021 15:36:24 Liam R. Howlett wrote:
> ---
> mm/khugepaged.c | 11 +++++++++--
> 1 file changed, 9 insertions(+), 2 deletions(-)
Good work. And a nit below.
>
> diff --git a/mm/khugepaged.c b/mm/khugepaged.c
> index 33cf91529f0b..4983a25c5a90 100644
> --- a/mm/khugepaged.c
> +++ b/mm/khugepaged.c
> @@ -2063,6 +2063,7 @@ static unsigned int khugepaged_scan_mm_slot(unsigned =
> int pages,
> struct mm_struct *mm;
> struct vm_area_struct *vma;
> int progress = 0;
> + MA_STATE(mas, NULL, 0, 0);
>
> VM_BUG_ON(!pages);
> lockdep_assert_held(&khugepaged_mm_lock);
> @@ -2079,18 +2080,22 @@ static unsigned int khugepaged_scan_mm_slot(unsigne=
> d int pages,
> khugepaged_collapse_pte_mapped_thps(mm_slot);
>
> mm = mm_slot->mm;
> + mas.tree = &mm->mm_mt;
> /*
> * Don't wait for semaphore (to avoid long wait times). Just move to
> * the next mm on the list.
> */
> vma = NULL;
> + mas_set(&mas, khugepaged_scan.address);
> if (unlikely(!mmap_read_trylock(mm)))
> goto breakouterloop_mmap_lock;
> +
> + rcu_read_lock();
> if (likely(!khugepaged_test_exit(mm)))
> - vma = find_vma(mm, khugepaged_scan.address);
> + vma = mas_find(&mas, ULONG_MAX);
>
> progress++;
> - for (; vma; vma = vma->vm_next) {
> + mas_for_each(&mas, vma, ULONG_MAX) {
> unsigned long hstart, hend;
>
> cond_resched();
Given the added rcu_read_lock(), take another look at this scheduling
entry?
> @@ -2129,6 +2134,7 @@ static unsigned int khugepaged_scan_mm_slot(unsigned =
> int pages,
> pgoff_t pgoff = linear_page_index(vma,
> khugepaged_scan.address);
>
> + rcu_read_unlock();
> mmap_read_unlock(mm);
> ret = 1;
> khugepaged_scan_file(mm, file, pgoff, hpage);
> @@ -2149,6 +2155,7 @@ static unsigned int khugepaged_scan_mm_slot(unsigned =
> int pages,
> }
> }
> breakouterloop:
> + rcu_read_unlock();
> mmap_read_unlock(mm); /* exit_mmap will destroy ptes after this */
> breakouterloop_mmap_lock:
>
> --
> 2.30.2
