From: Vladimir Davydov <vdavydov.dev@gmail.com>
To: Sahitya Tummala <stummala@codeaurora.org>
Cc: Alexander Polakov <apolyakov@beget.ru>,
Andrew Morton <akpm@linux-foundation.org>,
Jan Kara <jack@suse.cz>,
viro@zeniv.linux.org.uk, linux-mm@kvack.org,
linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org
Subject: Re: [PATCH v3 1/2] mm/list_lru.c: fix list_lru_count_node() to be race free
Date: Wed, 28 Jun 2017 20:18:54 +0300 [thread overview]
Message-ID: <20170628171854.t4sjyjv55j673qzv@esperanza> (raw)
In-Reply-To: <1498630044-26724-1-git-send-email-stummala@codeaurora.org>
On Wed, Jun 28, 2017 at 11:37:23AM +0530, Sahitya Tummala wrote:
> list_lru_count_node() iterates over all memcgs to get
> the total number of entries on the node but it can race with
> memcg_drain_all_list_lrus(), which migrates the entries from
> a dead cgroup to another. This can return incorrect number of
> entries from list_lru_count_node().
>
> Fix this by keeping track of entries per node and simply return
> it in list_lru_count_node().
>
> Signed-off-by: Sahitya Tummala <stummala@codeaurora.org>
> ---
> include/linux/list_lru.h | 1 +
> mm/list_lru.c | 14 ++++++--------
> 2 files changed, 7 insertions(+), 8 deletions(-)
>
> diff --git a/include/linux/list_lru.h b/include/linux/list_lru.h
> index cb0ba9f..eff61bc 100644
> --- a/include/linux/list_lru.h
> +++ b/include/linux/list_lru.h
> @@ -44,6 +44,7 @@ struct list_lru_node {
> /* for cgroup aware lrus points to per cgroup lists, otherwise NULL */
> struct list_lru_memcg *memcg_lrus;
> #endif
> + long nr_count;
'nr_count' sounds awkward. I think it should be called 'nr_items'.
Other than that, looks good to me.
next prev parent reply other threads:[~2017-06-28 17:19 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-06-12 0:47 [PATCH] mm/list_lru.c: use cond_resched_lock() for nlru->lock Sahitya Tummala
2017-06-12 13:11 ` Jan Kara
2017-06-15 21:05 ` Andrew Morton
2017-06-16 14:44 ` Sahitya Tummala
2017-06-17 11:14 ` Vladimir Davydov
2017-06-20 2:52 ` Sahitya Tummala
2017-06-21 6:39 ` [PATCH v2] fs/dcache.c: fix spin lockup issue on nlru->lock Sahitya Tummala
2017-06-21 16:31 ` Vladimir Davydov
2017-06-22 16:31 ` Sahitya Tummala
2017-06-22 17:49 ` Vladimir Davydov
2017-06-28 6:07 ` [PATCH v3 1/2] mm/list_lru.c: fix list_lru_count_node() to be race free Sahitya Tummala
2017-06-28 6:07 ` [PATCH v3 2/2] fs/dcache.c: fix spin lockup issue on nlru->lock Sahitya Tummala
2017-06-28 17:18 ` Vladimir Davydov [this message]
2017-06-29 3:39 ` [PATCH v4 1/2] mm/list_lru.c: fix list_lru_count_node() to be race free Sahitya Tummala
2017-07-01 16:28 ` Vladimir Davydov
2017-06-29 3:39 ` [PATCH v4 2/2] fs/dcache.c: fix spin lockup issue on nlru->lock Sahitya Tummala
2017-06-29 22:48 ` Andrew Morton
2017-06-30 3:16 ` Sahitya Tummala
2017-07-01 16:28 ` Vladimir Davydov
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