On Mon, 24 Aug 2020, Alex Shi wrote:
> From: Hugh Dickins <hughd@xxxxxxxxxx>
>
> Use the relock function to replace relocking action. And try to save few
> lock times.
>
> Signed-off-by: Hugh Dickins <hughd@xxxxxxxxxx>
> Signed-off-by: Alex Shi <alex.shi@xxxxxxxxxxxxxxxxx>
> Reviewed-by: Alexander Duyck <alexander.h.duyck@xxxxxxxxxxxxxxx>
NAK. Who wrote this rubbish? Oh, did I? Maybe something you extracted
from my tarball. No, we don't need any of this now, as explained when
going through 20/32.
> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
> Cc: Tejun Heo <tj@xxxxxxxxxx>
> Cc: Andrey Ryabinin <aryabinin@xxxxxxxxxxxxx>
> Cc: Jann Horn <jannh@xxxxxxxxxx>
> Cc: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx>
> Cc: Johannes Weiner <hannes@xxxxxxxxxxx>
> Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx>
> Cc: Hugh Dickins <hughd@xxxxxxxxxx>
> Cc: cgroups@xxxxxxxxxxxxxxx
> Cc: linux-kernel@xxxxxxxxxxxxxxx
> Cc: linux-mm@xxxxxxxxx
> ---
> mm/vmscan.c | 17 ++++++-----------
> 1 file changed, 6 insertions(+), 11 deletions(-)
>
> diff --git a/mm/vmscan.c b/mm/vmscan.c
> index 2c94790d4cb1..04ef94190530 100644
> --- a/mm/vmscan.c
> +++ b/mm/vmscan.c
> @@ -1848,15 +1848,15 @@ static unsigned noinline_for_stack move_pages_to_lru(struct lruvec *lruvec,
> enum lru_list lru;
>
> while (!list_empty(list)) {
> - struct lruvec *new_lruvec = NULL;
> -
> page = lru_to_page(list);
> VM_BUG_ON_PAGE(PageLRU(page), page);
> list_del(&page->lru);
> if (unlikely(!page_evictable(page))) {
> - spin_unlock_irq(&lruvec->lru_lock);
> + if (lruvec) {
> + spin_unlock_irq(&lruvec->lru_lock);
> + lruvec = NULL;
> + }
> putback_lru_page(page);
> - spin_lock_irq(&lruvec->lru_lock);
> continue;
> }
>
> @@ -1871,12 +1871,7 @@ static unsigned noinline_for_stack move_pages_to_lru(struct lruvec *lruvec,
> * list_add(&page->lru,)
> * list_add(&page->lru,)
> */
> - new_lruvec = mem_cgroup_page_lruvec(page, page_pgdat(page));
> - if (new_lruvec != lruvec) {
> - if (lruvec)
> - spin_unlock_irq(&lruvec->lru_lock);
> - lruvec = lock_page_lruvec_irq(page);
> - }
> + lruvec = relock_page_lruvec_irq(page, lruvec);
> SetPageLRU(page);
>
> if (unlikely(put_page_testzero(page))) {
> @@ -1885,8 +1880,8 @@ static unsigned noinline_for_stack move_pages_to_lru(struct lruvec *lruvec,
>
> if (unlikely(PageCompound(page))) {
> spin_unlock_irq(&lruvec->lru_lock);
> + lruvec = NULL;
> destroy_compound_page(page);
> - spin_lock_irq(&lruvec->lru_lock);
> } else
> list_add(&page->lru, &pages_to_free);
>
> --
> 1.8.3.1
