Re: [PATCH v2] mm: swap: use fixed-size readahead during swapoff

From: Huang\, Ying
Date: Wed Apr 15 2020 - 03:44:44 EST


Andrea Righi <andrea.righi@xxxxxxxxxxxxx> writes:

> mm/swapfile.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/mm/swapfile.c b/mm/swapfile.c
> index 9fd47e6f7a86..cb9eb517178d 100644
> --- a/mm/swapfile.c
> +++ b/mm/swapfile.c
> @@ -1944,7 +1944,9 @@ static int unuse_pte_range(struct vm_area_struct *vma, pmd_t *pmd,
> vmf.pmd = pmd;
> last_ra = atomic_read(&last_readahead_pages);
> atomic_set(&swapin_readahead_hits, last_ra);

You need to remove the above 2 lines firstly.

Best Regards,
Huang, Ying

> - page = swapin_readahead(entry, GFP_HIGHUSER_MOVABLE, &vmf);
> + page = lookup_swap_cache(entry, vma, addr);
> + if (!page)
> + page = swapin_readahead(entry, GFP_HIGHUSER_MOVABLE, &vmf);
> if (!page) {
> if (*swap_map == 0 || *swap_map == SWAP_MAP_BAD)
> goto try_next;
>
> Thanks!
> -Andrea