From: Roman Gushchin <guro@fb.com>
To: Muchun Song <songmuchun@bytedance.com>
Cc: <hannes@cmpxchg.org>, <mhocko@kernel.org>,
<akpm@linux-foundation.org>, <shakeelb@google.com>,
<vdavydov.dev@gmail.com>, <linux-kernel@vger.kernel.org>,
<linux-mm@kvack.org>, <duanxiongchun@bytedance.com>,
<fam.zheng@bytedance.com>, <bsingharora@gmail.com>,
<shy828301@gmail.com>, <alex.shi@linux.alibaba.com>
Subject: Re: [RFC PATCH v3 02/12] mm: memcontrol: introduce compact_lock_page_lruvec_irqsave
Date: Tue, 25 May 2021 10:21:10 -0700 [thread overview]
Message-ID: <YK0yBhDj+9zJlz/d@carbon.dhcp.thefacebook.com> (raw)
In-Reply-To: <20210421070059.69361-3-songmuchun@bytedance.com>
On Wed, Apr 21, 2021 at 03:00:49PM +0800, Muchun Song wrote:
> If we reuse the objcg APIs to charge LRU pages, the page_memcg()
> can be changed when the LRU pages reparented. In this case, we need
> to acquire the new lruvec lock.
>
> lruvec = mem_cgroup_page_lruvec(page);
>
> // The page is reparented.
>
> compact_lock_irqsave(&lruvec->lru_lock, &flags, cc);
>
> // Acquired the wrong lruvec lock and need to retry.
>
> But compact_lock_irqsave() only take lruvec lock as the parameter,
> we cannot aware this change. If it can take the page as parameter
> to acquire the lruvec lock. When the page memcg is changed, we can
> use the page_memcg() detect whether we need to reacquire the new
> lruvec lock. So compact_lock_irqsave() is not suitable for us.
> Similar to lock_page_lruvec_irqsave(), introduce
> compact_lock_page_lruvec_irqsave() to acquire the lruvec lock in
> the compaction routine.
>
> Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Acked-by: Roman Gushchin <guro@fb.com>
> ---
> mm/compaction.c | 27 ++++++++++++++++++++++++---
> 1 file changed, 24 insertions(+), 3 deletions(-)
>
> diff --git a/mm/compaction.c b/mm/compaction.c
> index 1c500e697c88..082293587cc6 100644
> --- a/mm/compaction.c
> +++ b/mm/compaction.c
> @@ -511,6 +511,29 @@ static bool compact_lock_irqsave(spinlock_t *lock, unsigned long *flags,
> return true;
> }
>
> +static struct lruvec *
> +compact_lock_page_lruvec_irqsave(struct page *page, unsigned long *flags,
> + struct compact_control *cc)
Maybe compact_lock_page_irqsave() to make it more similar to
compact_lock_irqsafe()? But it's up to you.
Thanks!
next prev parent reply other threads:[~2021-05-25 17:21 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-21 7:00 [RFC PATCH v3 00/12] Use obj_cgroup APIs to charge the LRU pages Muchun Song
2021-04-21 7:00 ` [RFC PATCH v3 01/12] mm: memcontrol: move the objcg infrastructure out of CONFIG_MEMCG_KMEM Muchun Song
2021-05-25 16:27 ` Roman Gushchin
2021-05-26 2:46 ` [External] " Muchun Song
2021-04-21 7:00 ` [RFC PATCH v3 02/12] mm: memcontrol: introduce compact_lock_page_lruvec_irqsave Muchun Song
2021-05-25 17:21 ` Roman Gushchin [this message]
2021-05-26 2:49 ` [External] " Muchun Song
2021-04-21 7:00 ` [RFC PATCH v3 03/12] mm: memcontrol: make lruvec lock safe when the LRU pages reparented Muchun Song
2021-05-25 17:21 ` Roman Gushchin
2021-04-21 7:00 ` [RFC PATCH v3 04/12] mm: vmscan: rework move_pages_to_lru() Muchun Song
2021-04-21 7:00 ` [RFC PATCH v3 05/12] mm: thp: introduce lock/unlock_split_queue{_irqsave}() Muchun Song
2021-04-21 7:00 ` [RFC PATCH v3 06/12] mm: thp: make deferred split queue lock safe when the LRU pages reparented Muchun Song
2021-04-21 7:00 ` [RFC PATCH v3 07/12] mm: memcontrol: make all the callers of page_memcg() safe Muchun Song
2021-04-21 7:00 ` [RFC PATCH v3 08/12] mm: memcontrol: introduce memcg_reparent_ops Muchun Song
2021-05-25 17:46 ` Roman Gushchin
2021-05-26 3:01 ` [External] " Muchun Song
2021-04-21 7:00 ` [RFC PATCH v3 09/12] mm: memcontrol: use obj_cgroup APIs to charge the LRU pages Muchun Song
2021-04-21 7:00 ` [RFC PATCH v3 10/12] mm: memcontrol: rename {un}lock_page_memcg() to {un}lock_page_objcg() Muchun Song
2021-04-21 7:00 ` [RFC PATCH v3 11/12] mm: lru: add VM_BUG_ON_PAGE to lru maintenance function Muchun Song
2021-04-21 7:00 ` [RFC PATCH v3 12/12] mm: lru: use lruvec lock to serialize memcg changes Muchun Song
2021-05-18 13:49 ` [RFC PATCH v3 00/12] Use obj_cgroup APIs to charge the LRU pages Muchun Song
2021-05-18 14:17 ` Roman Gushchin
2021-05-20 3:20 ` [External] " Muchun Song
2021-05-25 17:35 ` Roman Gushchin
2021-05-26 2:41 ` Muchun Song
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