From: Dan Streetman <ddstreet@ieee.org>
To: alex_y_xu@yahoo.ca
Cc: Linux-MM <linux-mm@kvack.org>,
linux-kernel <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] mm: fix z3fold warnings on CONFIG_SMP=n
Date: Thu, 27 Sep 2018 16:41:21 -0400 [thread overview]
Message-ID: <CALZtONA9r6=gnK-5a++tjaReqEnRzrBb3hzYMTFNXZ13z+UOWQ@mail.gmail.com> (raw)
In-Reply-To: <1538079759.qxp8zh3nwh.astroid@alex-archsus.none>
On Thu, Sep 27, 2018 at 4:27 PM Alex Xu (Hello71) <alex_y_xu@yahoo.ca> wrote:
>
> Spinlocks are always lockable on UP systems, even if they were just
> locked.
i think it would be much better to just use either
assert_spin_locked() or just spin_is_locked(), instead of an #ifdef.
>
> Cc: Dan Streetman <ddstreet@ieee.org>
> Signed-off-by: Alex Xu (Hello71) <alex_y_xu@yahoo.ca>
> ---
> mm/z3fold.c | 13 ++++++++++---
> 1 file changed, 10 insertions(+), 3 deletions(-)
>
> diff --git a/mm/z3fold.c b/mm/z3fold.c
> index 4b366d181..4e6ad2de4 100644
> --- a/mm/z3fold.c
> +++ b/mm/z3fold.c
> @@ -202,6 +202,13 @@ static inline void z3fold_page_lock(struct z3fold_header *zhdr)
> spin_lock(&zhdr->page_lock);
> }
>
> +static inline void z3fold_page_ensure_locked(struct z3fold_header *zhdr)
> +{
> +#ifdef CONFIG_SMP
> + WARN_ON(z3fold_page_trylock(zhdr));
> +#endif
> +}
> +
> /* Try to lock a z3fold page */
> static inline int z3fold_page_trylock(struct z3fold_header *zhdr)
> {
> @@ -277,7 +284,7 @@ static void release_z3fold_page_locked(struct kref *ref)
> {
> struct z3fold_header *zhdr = container_of(ref, struct z3fold_header,
> refcount);
> - WARN_ON(z3fold_page_trylock(zhdr));
> + z3fold_page_ensure_locked(zhdr);
> __release_z3fold_page(zhdr, true);
> }
>
> @@ -289,7 +296,7 @@ static void release_z3fold_page_locked_list(struct kref *ref)
> list_del_init(&zhdr->buddy);
> spin_unlock(&zhdr->pool->lock);
>
> - WARN_ON(z3fold_page_trylock(zhdr));
> + z3fold_page_ensure_locked(zhdr);
> __release_z3fold_page(zhdr, true);
> }
>
> @@ -403,7 +410,7 @@ static void do_compact_page(struct z3fold_header *zhdr, bool locked)
>
> page = virt_to_page(zhdr);
> if (locked)
> - WARN_ON(z3fold_page_trylock(zhdr));
> + z3fold_page_ensure_locked(zhdr);
> else
> z3fold_page_lock(zhdr);
> if (WARN_ON(!test_and_clear_bit(NEEDS_COMPACTING, &page->private))) {
> --
> 2.19.0
>
next prev parent reply other threads:[~2018-09-27 20:42 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-09-27 20:27 [PATCH] mm: fix z3fold warnings on CONFIG_SMP=n Alex Xu (Hello71)
2018-09-27 20:41 ` Dan Streetman [this message]
2018-09-27 21:12 ` Alex Xu
2018-09-27 21:15 ` [PATCH v2] " Alex Xu (Hello71)
2018-09-28 11:31 ` Dan Streetman
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