From: Matthew Wilcox <willy@infradead.org>
To: yanghui <yanghui.def@bytedance.com>
Cc: akpm@linux-foundation.org, linux-mm@kvack.org, songmuchun@bytedance.com
Subject: Re: [PATCH] mm/mempolicy: fix a race between offset_il_node and mpol_rebind_task
Date: Fri, 13 Aug 2021 17:57:50 +0100 [thread overview]
Message-ID: <YRakjlObxOOYgfCw@casper.infradead.org> (raw)
In-Reply-To: <20210813164053.51481-1-yanghui.def@bytedance.com>
On Sat, Aug 14, 2021 at 12:40:53AM +0800, yanghui wrote:
> +++ b/mm/mempolicy.c
> @@ -193,7 +193,7 @@ static int mpol_new_interleave(struct mempolicy *pol, const nodemask_t *nodes)
> {
> if (nodes_empty(*nodes))
> return -EINVAL;
> - pol->nodes = *nodes;
> + WRITE_ONCE(pol->nodes, *nodes);
typedef struct { DECLARE_BITMAP(bits, MAX_NUMNODES); } nodemask_t;
If MAX_NUMNODES is large enough, is WRITE_ONCE going to work? It could
be 128 bits, and few architectures have an atomic 128-bit store
instruction.
next prev parent reply other threads:[~2021-08-13 16:58 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-08-13 16:40 yanghui
2021-08-13 16:57 ` Matthew Wilcox [this message]
2021-08-14 2:37 ` Muchun Song
2021-08-14 3:11 ` Matthew Wilcox
2021-08-13 23:16 ` kernel test robot
2021-08-14 1:35 ` Nathan Chancellor
2021-08-14 1:40 ` kernel test robot
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