linux-kernel - Re: [PATCH] mm/z3fold: do not unlock in z3fold_page

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Message-ID: <CAPp=jc_J7fO74ygbZJV0SqDQ3=Zj8j7VW+OAoo6wvcgAT-Y2pg@mail.gmail.com>
Date:   Wed, 20 Jul 2022 15:05:30 +0800
From:   jingxiang zeng <zengjx95@...il.com>
To:     vitaly.wool@...sulko.com, linmiaohe@...wei.com,
        akpm@...ux-foundation.org
Cc:     linux-mm@...ck.org, linux-kernel@...r.kernel.org,
        Zeng Jingxiang <linuszeng@...cent.com>
Subject: Re: [PATCH] mm/z3fold: do not unlock in z3fold_page_putback()

<zengjx95@...il.com> 于2022年7月20日周三 14:58写道：
>
> From: Zeng Jingxiang <linuszeng@...cent.com>
>
> z3fold_page_lock() will lock zhdr->page_lock
> 1630    z3fold_page_lock(zhdr);
>
> return without unlocking zhdr->page_lock
> 1634    if (kref_put(&zhdr->refcount, release_z3fold_page_locked))
> 1635            return;
>
> Signed-off-by: Zeng Jingxiang <linuszeng@...cent.com>
> ---
>  mm/z3fold.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/mm/z3fold.c b/mm/z3fold.c
> index f41f8b0d9e9a..03785832ad47 100644
> --- a/mm/z3fold.c
> +++ b/mm/z3fold.c
> @@ -1632,13 +1632,14 @@ static void z3fold_page_putback(struct page *page)
>                 list_del_init(&zhdr->buddy);
>         INIT_LIST_HEAD(&page->lru);
>         if (kref_put(&zhdr->refcount, release_z3fold_page_locked))
> -               return;
> +               goto ret;
>         spin_lock(&pool->lock);
>         list_add(&page->lru, &pool->lru);
>         spin_unlock(&pool->lock);
>         if (list_empty(&zhdr->buddy))
>                 add_to_unbuddied(pool, zhdr);
>         clear_bit(PAGE_CLAIMED, &page->private);
> +ret:
>         z3fold_page_unlock(zhdr);
>  }
>
> --
> 2.27.0
>
Sorry, I just misunderstood the code logic, please ignore this patch.