From: Michal Hocko <mhocko@kernel.org>
To: Johannes Weiner <hannes@cmpxchg.org>
Cc: Andrew Morton <akpm@linux-foundation.org>,
linux-mm@kvack.org, cgroups@vger.kernel.org,
linux-kernel@vger.kernel.org, kernel-team@fb.com
Subject: Re: [PATCH 3/8] mm: vmscan: move inactive_list_is_low() swap check to the caller
Date: Wed, 23 Oct 2019 16:06:42 +0200 [thread overview]
Message-ID: <20191023140642.GD17610@dhcp22.suse.cz> (raw)
In-Reply-To: <20191022144803.302233-4-hannes@cmpxchg.org>
On Tue 22-10-19 10:47:58, Johannes Weiner wrote:
> inactive_list_is_low() should be about one thing: checking the ratio
> between inactive and active list. Kitchensink checks like the one for
> swap space makes the function hard to use and modify its
> callsites. Luckly, most callers already have an understanding of the
> swap situation, so it's easy to clean up.
>
> get_scan_count() has its own, memcg-aware swap check, and doesn't even
> get to the inactive_list_is_low() check on the anon list when there is
> no swap space available.
>
> shrink_list() is called on the results of get_scan_count(), so that
> check is redundant too.
>
> age_active_anon() has its own totalswap_pages check right before it
> checks the list proportions.
>
> The shrink_node_memcg() site is the only one that doesn't do its own
> swap check. Add it there.
>
> Then delete the swap check from inactive_list_is_low().
>
> Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
OK, makes sense to me.
Acked-by: Michal Hocko <mhocko@suse.com>
> ---
> mm/vmscan.c | 9 +--------
> 1 file changed, 1 insertion(+), 8 deletions(-)
>
> diff --git a/mm/vmscan.c b/mm/vmscan.c
> index be3c22c274c1..622b77488144 100644
> --- a/mm/vmscan.c
> +++ b/mm/vmscan.c
> @@ -2226,13 +2226,6 @@ static bool inactive_list_is_low(struct lruvec *lruvec, bool file,
> unsigned long refaults;
> unsigned long gb;
>
> - /*
> - * If we don't have swap space, anonymous page deactivation
> - * is pointless.
> - */
> - if (!file && !total_swap_pages)
> - return false;
> -
> inactive = lruvec_lru_size(lruvec, inactive_lru, sc->reclaim_idx);
> active = lruvec_lru_size(lruvec, active_lru, sc->reclaim_idx);
>
> @@ -2653,7 +2646,7 @@ static void shrink_node_memcg(struct pglist_data *pgdat, struct mem_cgroup *memc
> * Even if we did not try to evict anon pages at all, we want to
> * rebalance the anon lru active/inactive ratio.
> */
> - if (inactive_list_is_low(lruvec, false, sc, true))
> + if (total_swap_pages && inactive_list_is_low(lruvec, false, sc, true))
> shrink_active_list(SWAP_CLUSTER_MAX, lruvec,
> sc, LRU_ACTIVE_ANON);
> }
> --
> 2.23.0
--
Michal Hocko
SUSE Labs
next prev parent reply other threads:[~2019-10-23 14:06 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-22 14:47 [PATCH 0/8]: mm: vmscan: cgroup-related cleanups Johannes Weiner
2019-10-22 14:47 ` [PATCH 1/8] mm: vmscan: simplify lruvec_lru_size() Johannes Weiner
2019-10-22 19:18 ` Roman Gushchin
2019-10-23 13:48 ` Michal Hocko
2019-10-22 14:47 ` [PATCH 2/8] mm: clean up and clarify lruvec lookup procedure Johannes Weiner
2019-10-22 19:25 ` Roman Gushchin
2019-10-22 21:31 ` Johannes Weiner
2019-10-23 14:00 ` Michal Hocko
2019-10-22 14:47 ` [PATCH 3/8] mm: vmscan: move inactive_list_is_low() swap check to the caller Johannes Weiner
2019-10-22 19:28 ` Roman Gushchin
2019-10-23 14:06 ` Michal Hocko [this message]
2019-10-22 14:47 ` [PATCH 4/8] mm: vmscan: naming fixes: global_reclaim() and sane_reclaim() Johannes Weiner
2019-10-22 19:40 ` Roman Gushchin
2019-10-23 16:02 ` Johannes Weiner
2019-10-23 14:14 ` Michal Hocko
2019-10-23 15:56 ` Johannes Weiner
2019-10-22 14:48 ` [PATCH 5/8] mm: vmscan: replace shrink_node() loop with a retry jump Johannes Weiner
2019-10-22 19:56 ` Roman Gushchin
2019-10-22 21:42 ` Johannes Weiner
2019-10-22 22:46 ` Roman Gushchin
2019-10-23 14:18 ` Michal Hocko
2019-10-25 13:44 ` Johannes Weiner
2019-10-22 14:48 ` [PATCH 6/8] mm: vmscan: turn shrink_node_memcg() into shrink_lruvec() Johannes Weiner
2019-10-22 20:04 ` Roman Gushchin
2019-10-23 14:21 ` Michal Hocko
2019-10-22 14:48 ` [PATCH 7/8] mm: vmscan: split shrink_node() into node part and memcgs part Johannes Weiner
2019-10-22 20:08 ` Roman Gushchin
2019-10-25 14:36 ` Johannes Weiner
2019-10-23 14:24 ` Michal Hocko
2019-10-22 14:48 ` [PATCH 8/8] mm: vmscan: harmonize writeback congestion tracking for nodes & memcgs Johannes Weiner
2019-10-22 21:03 ` Roman Gushchin
2019-10-25 14:41 ` Johannes Weiner
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