From: Mike Kravetz <mike.kravetz@oracle.com>
To: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Michal Hocko <mhocko@kernel.org>,
"linux-mm@kvack.org" <linux-mm@kvack.org>,
Andrew Morton <akpm@linux-foundation.org>,
"xishi.qiuxishi@alibaba-inc.com" <xishi.qiuxishi@alibaba-inc.com>,
"zy.zhengyi@alibaba-inc.com" <zy.zhengyi@alibaba-inc.com>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v2 1/2] mm: fix race on soft-offlining free huge pages
Date: Tue, 17 Jul 2018 19:36:47 -0700 [thread overview]
Message-ID: <161a4a4c-4311-9d68-fe05-b22d7e33dd61@oracle.com> (raw)
In-Reply-To: <20180718012817.GB12184@hori1.linux.bs1.fc.nec.co.jp>
On 07/17/2018 06:28 PM, Naoya Horiguchi wrote:
> On Tue, Jul 17, 2018 at 01:10:39PM -0700, Mike Kravetz wrote:
>> It seems that soft_offline_free_page can be called for in use pages.
>> Certainly, that is the case in the first workflow above. With the
>> suggested changes, I think this is OK for huge pages. However, it seems
>> that setting HWPoison on a in use non-huge page could cause issues?
>
> Just after dissolve_free_huge_page() returns, the target page is just a
> free buddy page without PageHWPoison set. If this page is allocated
> immediately, that's "migration succeeded, but soft offline failed" case,
> so no problem.
> Certainly, there also is a race between cheking TestSetPageHWPoison and
> page allocation, so this issue is handled in patch 2/2.
Yes, the issue of calling soft_offline_free_page() for an 'in use' page
is handled in the new routine set_hwpoison_free_buddy_page() of patch 2/2.
Thanks,
--
Mike Kravetz
next prev parent reply other threads:[~2018-07-18 2:37 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-07-17 5:32 [PATCH v2 0/2] mm: soft-offline: fix race against page allocation Naoya Horiguchi
2018-07-17 5:32 ` [PATCH v2 1/2] mm: fix race on soft-offlining free huge pages Naoya Horiguchi
2018-07-17 14:27 ` Michal Hocko
2018-07-17 20:10 ` Mike Kravetz
2018-07-18 1:28 ` Naoya Horiguchi
2018-07-18 2:36 ` Mike Kravetz [this message]
2018-07-18 0:55 ` Naoya Horiguchi
2018-07-18 1:41 ` Naoya Horiguchi
2018-07-18 8:50 ` Michal Hocko
2018-07-19 6:19 ` Naoya Horiguchi
2018-07-19 7:15 ` Michal Hocko
2018-07-19 8:08 ` Naoya Horiguchi
2018-07-19 8:27 ` Michal Hocko
2018-07-19 9:22 ` Naoya Horiguchi
2018-07-19 10:32 ` Michal Hocko
2018-07-17 5:32 ` [PATCH v2 2/2] mm: soft-offline: close the race against page allocation Naoya Horiguchi
2018-08-15 22:43 ` [PATCH v2 0/2] mm: soft-offline: fix " Andrew Morton
2018-08-22 1:37 ` Naoya Horiguchi
2018-08-22 2:25 ` Mike Kravetz
2018-08-22 8:00 ` Michal Hocko
2018-10-26 8:46 ` Michal Hocko
2018-10-30 6:54 ` Naoya Horiguchi
2018-10-30 8:16 ` Michal Hocko
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