From: sunqiuyang <sunqiuyang@huawei.com>
To: Michal Hocko <mhocko@kernel.org>
Cc: "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"linux-mm@kvack.org" <linux-mm@kvack.org>
Subject: RE: [PATCH 1/1] mm/migrate: fix list corruption in migration of non-LRU movable pages
Date: Wed, 4 Sep 2019 12:19:11 +0000 [thread overview]
Message-ID: <157FC541501A9C4C862B2F16FFE316DC190C3402@dggeml512-mbx.china.huawei.com> (raw)
In-Reply-To: <20190904081408.GF3838@dhcp22.suse.cz>
________________________________________
From: Michal Hocko [mhocko@kernel.org]
Sent: Wednesday, September 04, 2019 16:14
To: sunqiuyang
Cc: linux-kernel@vger.kernel.org; linux-mm@kvack.org
Subject: Re: [PATCH 1/1] mm/migrate: fix list corruption in migration of non-LRU movable pages
Do not top post please
On Wed 04-09-19 07:27:25, sunqiuyang wrote:
> isolate_migratepages_block() from another thread may try to isolate the page again:
>
> for (; low_pfn < end_pfn; low_pfn++) {
> /* ... */
> page = pfn_to_page(low_pfn);
> /* ... */
> if (!PageLRU(page)) {
> if (unlikely(__PageMovable(page)) && !PageIsolated(page)) {
> /* ... */
> if (!isolate_movable_page(page, isolate_mode))
> goto isolate_success;
> /*... */
> isolate_success:
> list_add(&page->lru, &cc->migratepages);
>
> And this page will be added to another list.
> Or, do you see any reason that the page cannot go through this path?
The page shouldn't be __PageMovable after the migration is done. All the
state should have been transfered to the new page IIUC.
----
I don't see where page->mapping is modified after the migration is done.
Actually, the last comment in move_to_new_page() says,
"Anonymous and movable page->mapping will be cleard by
free_pages_prepare so don't reset it here for keeping
the type to work PageAnon, for example. "
Or did I miss something? Thanks,
--
Michal Hocko
SUSE Labs
next prev parent reply other threads:[~2019-09-04 12:19 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-09-03 8:27 [PATCH 1/1] mm/migrate: fix list corruption in migration of non-LRU movable pages sunqiuyang
2019-09-03 13:17 ` Michal Hocko
2019-09-04 2:18 ` sunqiuyang
2019-09-04 6:38 ` Michal Hocko
2019-09-04 7:27 ` sunqiuyang
2019-09-04 8:14 ` Michal Hocko
2019-09-04 12:19 ` sunqiuyang [this message]
2019-09-04 12:52 ` Michal Hocko
2019-09-05 1:44 ` sunqiuyang
2019-09-09 8:40 ` Michal Hocko
2019-09-12 17:21 ` Minchan Kim
2019-09-10 19:23 ` Minchan Kim
2019-09-10 19:31 ` Michal Hocko
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