Hi:
On 2021/12/10 8:30, Minchan Kim wrote:
> Likewise shrink_lruvec[1], madvise_pageout could get the benefit
> from per-task block plug.
>
> [1] 3da367c3e5fc, vmscan: add block plug for page reclaim
It seems there is a block plug in the caller do_madvise already. This one
might not be necessary for madvise.
Many thanks.
> Signed-off-by: Minchan Kim <minchan@xxxxxxxxxx>
> ---
> mm/vmscan.c | 4 ++++
> 1 file changed, 4 insertions(+)
>
> diff --git a/mm/vmscan.c b/mm/vmscan.c
> index fb9584641ac7..cf11113f6adb 100644
> --- a/mm/vmscan.c
> +++ b/mm/vmscan.c
> @@ -2556,6 +2556,7 @@ unsigned long reclaim_pages(struct list_head *page_list)
> struct reclaim_stat dummy_stat;
> struct page *page;
> unsigned int noreclaim_flag;
> + struct blk_plug plug;
> struct scan_control sc = {
> .gfp_mask = GFP_KERNEL,
> .may_writepage = 1,
> @@ -2564,6 +2565,7 @@ unsigned long reclaim_pages(struct list_head *page_list)
> .no_demotion = 1,
> };
>
> + blk_start_plug(&plug);
> noreclaim_flag = memalloc_noreclaim_save();
>
> while (!list_empty(page_list)) {
> @@ -2603,6 +2605,8 @@ unsigned long reclaim_pages(struct list_head *page_list)
> }
>
> memalloc_noreclaim_restore(noreclaim_flag);
> + blk_finish_plug(&plug);
> +
>
> return nr_reclaimed;
> }
>
