From: Michal Hocko <mhocko@kernel.org>
To: Xunlei Pang <xlpang@linux.alibaba.com>
Cc: Roman Gushchin <guro@fb.com>,
Johannes Weiner <hannes@cmpxchg.org>,
linux-kernel@vger.kernel.org, linux-mm@kvack.org
Subject: Re: [PATCH 1/3] mm/memcg: Fix min/low usage in propagate_protected_usage()
Date: Mon, 3 Dec 2018 12:54:53 +0100 [thread overview]
Message-ID: <20181203115453.GO31738@dhcp22.suse.cz> (raw)
In-Reply-To: <20181203080119.18989-1-xlpang@linux.alibaba.com>
On Mon 03-12-18 16:01:17, Xunlei Pang wrote:
> When usage exceeds min, min usage should be min other than 0.
> Apply the same for low.
Why? What is the actual problem.
> Signed-off-by: Xunlei Pang <xlpang@linux.alibaba.com>
> ---
> mm/page_counter.c | 12 ++----------
> 1 file changed, 2 insertions(+), 10 deletions(-)
>
> diff --git a/mm/page_counter.c b/mm/page_counter.c
> index de31470655f6..75d53f15f040 100644
> --- a/mm/page_counter.c
> +++ b/mm/page_counter.c
> @@ -23,11 +23,7 @@ static void propagate_protected_usage(struct page_counter *c,
> return;
>
> if (c->min || atomic_long_read(&c->min_usage)) {
> - if (usage <= c->min)
> - protected = usage;
> - else
> - protected = 0;
> -
> + protected = min(usage, c->min);
> old_protected = atomic_long_xchg(&c->min_usage, protected);
> delta = protected - old_protected;
> if (delta)
> @@ -35,11 +31,7 @@ static void propagate_protected_usage(struct page_counter *c,
> }
>
> if (c->low || atomic_long_read(&c->low_usage)) {
> - if (usage <= c->low)
> - protected = usage;
> - else
> - protected = 0;
> -
> + protected = min(usage, c->low);
> old_protected = atomic_long_xchg(&c->low_usage, protected);
> delta = protected - old_protected;
> if (delta)
> --
> 2.13.5 (Apple Git-94)
>
--
Michal Hocko
SUSE Labs
next prev parent reply other threads:[~2018-12-03 11:54 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-12-03 8:01 [PATCH 1/3] mm/memcg: Fix min/low usage in propagate_protected_usage() Xunlei Pang
2018-12-03 8:01 ` [PATCH 2/3] mm/vmscan: Enable kswapd to reclaim low-protected memory Xunlei Pang
2018-12-03 11:56 ` Michal Hocko
2018-12-03 15:20 ` Xunlei Pang
2018-12-03 17:22 ` Michal Hocko
2018-12-04 2:40 ` Xunlei Pang
2018-12-04 7:25 ` Michal Hocko
2018-12-04 8:44 ` Xunlei Pang
2018-12-03 8:01 ` [PATCH 3/3] mm/memcg: Avoid reclaiming below hard protection Xunlei Pang
2018-12-03 11:57 ` Michal Hocko
2018-12-04 2:53 ` Xunlei Pang
2018-12-03 11:54 ` Michal Hocko [this message]
2018-12-03 14:49 ` [PATCH 1/3] mm/memcg: Fix min/low usage in propagate_protected_usage() Xunlei Pang
2018-12-03 18:00 ` Roman Gushchin
2018-12-05 8:58 ` Xunlei Pang
2018-12-05 23:11 ` Roman Gushchin
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