From: Michal Hocko <mhocko@suse.com>
To: Muchun Song <songmuchun@bytedance.com>
Cc: mike.kravetz@oracle.com, akpm@linux-foundation.org,
n-horiguchi@ah.jp.nec.com, ak@linux.intel.com,
linux-mm@kvack.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2 4/6] mm: hugetlb: add return -EAGAIN for dissolve_free_huge_page
Date: Wed, 6 Jan 2021 18:07:54 +0100 [thread overview]
Message-ID: <20210106170754.GU13207@dhcp22.suse.cz> (raw)
In-Reply-To: <20210106084739.63318-5-songmuchun@bytedance.com>
On Wed 06-01-21 16:47:37, Muchun Song wrote:
> When dissolve_free_huge_page() races with __free_huge_page(), we can
> do a retry. Because the race window is small.
Is this a bug fix or mere optimization. I have hard time to tell from
the description.
> Signed-off-by: Muchun Song <songmuchun@bytedance.com>
> ---
> mm/hugetlb.c | 26 +++++++++++++++++++++-----
> 1 file changed, 21 insertions(+), 5 deletions(-)
>
> diff --git a/mm/hugetlb.c b/mm/hugetlb.c
[...]
> @@ -1825,6 +1828,14 @@ int dissolve_free_huge_page(struct page *page)
> }
> out:
> spin_unlock(&hugetlb_lock);
> +
> + /*
> + * If the freeing of the HugeTLB page is put on a work queue, we should
> + * flush the work before retrying.
> + */
> + if (unlikely(rc == -EAGAIN))
> + flush_work(&free_hpage_work);
Is it safe to wait for the work to finish from this context?
--
Michal Hocko
SUSE Labs
next prev parent reply other threads:[~2021-01-06 17:07 UTC|newest]
Thread overview: 56+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-06 8:47 [PATCH v2 0/6] Fix some bugs about HugeTLB code Muchun Song
2021-01-06 8:47 ` [PATCH v2 1/6] mm: migrate: do not migrate HugeTLB page whose refcount is one Muchun Song
2021-01-06 16:13 ` Michal Hocko
2021-01-07 2:52 ` [External] " Muchun Song
2021-01-07 11:16 ` Michal Hocko
2021-01-07 11:24 ` Muchun Song
2021-01-07 11:48 ` Michal Hocko
2021-01-06 8:47 ` [PATCH v2 2/6] mm: hugetlbfs: fix cannot migrate the fallocated HugeTLB page Muchun Song
2021-01-06 16:35 ` Michal Hocko
2021-01-06 19:30 ` Mike Kravetz
2021-01-06 20:02 ` Michal Hocko
2021-01-06 21:07 ` Mike Kravetz
2021-01-07 8:36 ` Michal Hocko
2021-01-07 2:58 ` [External] " Muchun Song
2021-01-06 8:47 ` [PATCH v2 3/6] mm: hugetlb: fix a race between freeing and dissolving the page Muchun Song
2021-01-06 16:56 ` Michal Hocko
2021-01-06 20:58 ` Mike Kravetz
2021-01-07 3:08 ` [External] " Muchun Song
2021-01-07 8:40 ` Michal Hocko
2021-01-08 0:52 ` Mike Kravetz
2021-01-08 8:28 ` Michal Hocko
2021-01-07 5:39 ` [External] " Muchun Song
2021-01-07 8:41 ` Michal Hocko
2021-01-07 8:53 ` Muchun Song
2021-01-07 11:18 ` Michal Hocko
2021-01-07 11:38 ` Muchun Song
2021-01-07 12:38 ` Michal Hocko
2021-01-07 12:59 ` Muchun Song
2021-01-07 14:11 ` Michal Hocko
2021-01-07 15:11 ` Muchun Song
2021-01-08 1:06 ` Mike Kravetz
2021-01-08 2:38 ` Muchun Song
2021-01-08 8:43 ` Michal Hocko
2021-01-08 9:01 ` Muchun Song
2021-01-08 9:31 ` Michal Hocko
2021-01-08 10:08 ` Muchun Song
2021-01-08 11:44 ` Michal Hocko
2021-01-08 11:52 ` Muchun Song
2021-01-08 12:04 ` Michal Hocko
2021-01-08 12:24 ` Muchun Song
2021-01-06 8:47 ` [PATCH v2 4/6] mm: hugetlb: add return -EAGAIN for dissolve_free_huge_page Muchun Song
2021-01-06 17:07 ` Michal Hocko [this message]
2021-01-07 3:11 ` [External] " Muchun Song
2021-01-07 8:39 ` Michal Hocko
2021-01-07 9:01 ` Muchun Song
2021-01-07 11:22 ` Michal Hocko
2021-01-06 8:47 ` [PATCH v2 5/6] mm: hugetlb: fix a race between isolating and freeing page Muchun Song
2021-01-06 17:10 ` Michal Hocko
2021-01-06 8:47 ` [PATCH v2 6/6] mm: hugetlb: remove VM_BUG_ON_PAGE from page_huge_active Muchun Song
2021-01-06 17:16 ` Michal Hocko
2021-01-08 22:24 ` Mike Kravetz
2021-01-09 4:07 ` [External] " Muchun Song
2021-01-07 9:30 ` [PATCH v2 0/6] Fix some bugs about HugeTLB code David Hildenbrand
2021-01-07 9:40 ` [External] " Muchun Song
2021-01-07 10:10 ` David Hildenbrand
2021-01-07 10:16 ` Muchun Song
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