From: Yang Shi <shy828301@gmail.com>
To: David Hildenbrand <david@redhat.com>
Cc: Muchun Song <songmuchun@bytedance.com>,
Mike Kravetz <mike.kravetz@oracle.com>,
Andrew Morton <akpm@linux-foundation.org>,
hillf.zj@alibaba-inc.com,
Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>,
ak@linux.intel.com, yongjun_wei@trendmicro.com.cn,
mhocko@suse.cz, Linux MM <linux-mm@kvack.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 1/6] mm: migrate: do not migrate HugeTLB page whose refcount is one
Date: Tue, 5 Jan 2021 10:04:13 -0800 [thread overview]
Message-ID: <CAHbLzko4BH6GOJsz33NEbwLTxJQJxVHH3qLzHzoM1LycT=ccbg@mail.gmail.com> (raw)
In-Reply-To: <d81664e1-bde0-4dcb-f602-6eb201ceada0@redhat.com>
On Tue, Jan 5, 2021 at 8:58 AM David Hildenbrand <david@redhat.com> wrote:
>
> On 04.01.21 07:58, Muchun Song wrote:
> > If the refcount is one when it is migrated, it means that the page
> > was freed from under us. So we are done and do not need to migrate.
> >
> > Signed-off-by: Muchun Song <songmuchun@bytedance.com>
> > ---
> > mm/migrate.c | 6 ++++++
> > 1 file changed, 6 insertions(+)
> >
> > diff --git a/mm/migrate.c b/mm/migrate.c
> > index 4385f2fb5d18..a6631c4eb6a6 100644
> > --- a/mm/migrate.c
> > +++ b/mm/migrate.c
> > @@ -1279,6 +1279,12 @@ static int unmap_and_move_huge_page(new_page_t get_new_page,
> > return -ENOSYS;
> > }
> >
> > + if (page_count(hpage) == 1) {
> > + /* page was freed from under us. So we are done. */
> > + putback_active_hugepage(hpage);
> > + return MIGRATEPAGE_SUCCESS;
> > + }
> > +
> > new_hpage = get_new_page(hpage, private);
> > if (!new_hpage)
> > return -ENOMEM;
> >
>
> This series seems to fix quite some important cases (thanks). Do we want
> to cc stable some/all?
For this particular one, I don't think so IMHO. It is an optimization
rather than a bug fix.
>
> --
> Thanks,
>
> David / dhildenb
>
>
next prev parent reply other threads:[~2021-01-05 18:05 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-04 6:58 [PATCH 1/6] mm: migrate: do not migrate HugeTLB page whose refcount is one Muchun Song
2021-01-04 6:58 ` [PATCH 2/6] hugetlbfs: fix cannot migrate the fallocated HugeTLB page Muchun Song
2021-01-04 22:38 ` Mike Kravetz
2021-01-05 2:44 ` [External] " Muchun Song
2021-01-05 22:27 ` Mike Kravetz
2021-01-06 2:57 ` Muchun Song
2021-01-04 6:58 ` [PATCH 3/6] mm: hugetlb: fix a race between freeing and dissolving the page Muchun Song
2021-01-05 0:00 ` Mike Kravetz
2021-01-05 2:55 ` [External] " Muchun Song
2021-01-05 23:22 ` Mike Kravetz
2021-01-06 6:05 ` Muchun Song
2021-01-05 6:12 ` Muchun Song
2021-01-04 6:58 ` [PATCH 4/6] mm: hugetlb: add return -EAGAIN for dissolve_free_huge_page Muchun Song
2021-01-05 1:32 ` Mike Kravetz
2021-01-05 3:14 ` [External] " Muchun Song
2021-01-05 3:46 ` Muchun Song
2021-01-06 0:07 ` Mike Kravetz
2021-01-05 6:37 ` HORIGUCHI NAOYA(堀口 直也)
2021-01-05 7:10 ` [External] " Muchun Song
2021-01-05 7:30 ` HORIGUCHI NAOYA(堀口 直也)
2021-01-04 6:58 ` [PATCH 5/6] mm: hugetlb: fix a race between isolating and freeing page Muchun Song
2021-01-05 1:42 ` Mike Kravetz
2021-01-04 6:58 ` [PATCH 6/6] mm: hugetlb: remove VM_BUG_ON_PAGE from page_huge_active Muchun Song
2021-01-05 1:50 ` Mike Kravetz
2021-01-04 22:17 ` [PATCH 1/6] mm: migrate: do not migrate HugeTLB page whose refcount is one Mike Kravetz
2021-01-05 16:58 ` David Hildenbrand
2021-01-05 18:04 ` Yang Shi [this message]
2021-01-05 18:05 ` David Hildenbrand
2021-01-05 18:04 ` Yang Shi
2021-01-06 16:11 ` Michal Hocko
2021-01-06 16:12 ` Michal Hocko
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