Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
MIME-Version: 1.0
References: <20200818184704.3625199-1-yuzhao@google.com>
In-Reply-To: <20200818184704.3625199-1-yuzhao@google.com>
From:   Yang Shi <shy828301@gmail.com>
Date:   Wed, 19 Aug 2020 15:16:51 -0700
Message-ID: <CAHbLzkr4sKNaKnrzE00yFW2WNjYKo7NL0MohQN42a+oqMe6a8w@mail.gmail.com>
Subject: Re: [PATCH v2 1/3] mm: remove activate_page() from unuse_pte()
To:     Yu Zhao <yuzhao@google.com>
Cc:     Andrew Morton <akpm@linux-foundation.org>,
        Alexander Duyck <alexander.h.duyck@linux.intel.com>,
        Huang Ying <ying.huang@intel.com>,
        David Hildenbrand <david@redhat.com>,
        Michal Hocko <mhocko@suse.com>,
        Yang Shi <yang.shi@linux.alibaba.com>, Qian Cai <cai@lca.pw>,
        Mel Gorman <mgorman@suse.de>,
        Nicholas Piggin <npiggin@gmail.com>,
        =?UTF-8?B?SsOpcsO0bWUgR2xpc3Nl?= <jglisse@redhat.com>,
        Hugh Dickins <hughd@google.com>, Linux MM <linux-mm@kvack.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Joonsoo Kim <iamjoonsoo.kim@lge.com>
Content-Type: text/plain; charset="UTF-8"
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

On Tue, Aug 18, 2020 at 11:47 AM Yu Zhao <yuzhao@google.com> wrote:
>
> We don't initially add anon pages to active lruvec after
> commit b518154e59aa ("mm/vmscan: protect the workingset on anonymous LRU").
> Remove activate_page() from unuse_pte(), which seems to be missed by
> the commit. And make the function static while we are at it.
>
> Before the commit, we called lru_cache_add_active_or_unevictable() to
> add new ksm pages to active lruvec. Therefore, activate_page() wasn't
> necessary for them in the first place.

Reviewed-by: Yang Shi <shy828301@gmail.com>

>
> Signed-off-by: Yu Zhao <yuzhao@google.com>
> ---
>  include/linux/swap.h | 1 -
>  mm/swap.c            | 4 ++--
>  mm/swapfile.c        | 5 -----
>  3 files changed, 2 insertions(+), 8 deletions(-)
>
> diff --git a/include/linux/swap.h b/include/linux/swap.h
> index 661046994db4..df6207346078 100644
> --- a/include/linux/swap.h
> +++ b/include/linux/swap.h
> @@ -340,7 +340,6 @@ extern void lru_note_cost_page(struct page *);
>  extern void lru_cache_add(struct page *);
>  extern void lru_add_page_tail(struct page *page, struct page *page_tail,
>                          struct lruvec *lruvec, struct list_head *head);
> -extern void activate_page(struct page *);
>  extern void mark_page_accessed(struct page *);
>  extern void lru_add_drain(void);
>  extern void lru_add_drain_cpu(int cpu);
> diff --git a/mm/swap.c b/mm/swap.c
> index d16d65d9b4e0..25c4043491b3 100644
> --- a/mm/swap.c
> +++ b/mm/swap.c
> @@ -348,7 +348,7 @@ static bool need_activate_page_drain(int cpu)
>         return pagevec_count(&per_cpu(lru_pvecs.activate_page, cpu)) != 0;
>  }
>
> -void activate_page(struct page *page)
> +static void activate_page(struct page *page)
>  {
>         page = compound_head(page);
>         if (PageLRU(page) && !PageActive(page) && !PageUnevictable(page)) {
> @@ -368,7 +368,7 @@ static inline void activate_page_drain(int cpu)
>  {
>  }
>
> -void activate_page(struct page *page)
> +static void activate_page(struct page *page)
>  {
>         pg_data_t *pgdat = page_pgdat(page);
>
> diff --git a/mm/swapfile.c b/mm/swapfile.c
> index 12f59e641b5e..c287c560f96d 100644
> --- a/mm/swapfile.c
> +++ b/mm/swapfile.c
> @@ -1925,11 +1925,6 @@ static int unuse_pte(struct vm_area_struct *vma, pmd_t *pmd,
>                 lru_cache_add_inactive_or_unevictable(page, vma);
>         }
>         swap_free(entry);
> -       /*
> -        * Move the page to the active list so it is not
> -        * immediately swapped out again after swapon.
> -        */
> -       activate_page(page);
>  out:
>         pte_unmap_unlock(pte, ptl);
>         if (page != swapcache) {
> --
> 2.28.0.220.ged08abb693-goog
>
>