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Groups > linux.kernel > #1425644
| From | zhong jiang <zhongjiang@huawei.com> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | Re: [PATCH] mm: fix account pmd page to the process |
| Date | 2016-06-18 07:10 +0200 |
| Message-ID | <rLgG5-890-5@gated-at.bofh.it> (permalink) |
| References | (3 earlier) <rKI1H-25D-19@gated-at.bofh.it> <rKIuK-2fo-21@gated-at.bofh.it> <rKIEp-2jH-27@gated-at.bofh.it> <rL14m-6sY-21@gated-at.bofh.it> <rL42d-8iY-9@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
On 2016/6/17 23:39, Mike Kravetz wrote: > On 06/17/2016 05:25 AM, Kirill A. Shutemov wrote: >> From fd22922e7b4664e83653a84331f0a95b985bff0c Mon Sep 17 00:00:00 2001 >> From: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> >> Date: Fri, 17 Jun 2016 15:07:03 +0300 >> Subject: [PATCH] hugetlb: fix nr_pmds accounting with shared page tables >> >> We account HugeTLB's shared page table to all processes who share it. >> The accounting happens during huge_pmd_share(). >> >> If somebody populates pud entry under us, we should decrease pagetable's >> refcount and decrease nr_pmds of the process. >> >> By mistake, I increase nr_pmds again in this case. :-/ >> It will lead to "BUG: non-zero nr_pmds on freeing mm: 2" on process' >> exit. >> >> Let's fix this by increasing nr_pmds only when we're sure that the page >> table will be used. >> >> Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> > Nice, > Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com> > > I agree that we do not necessarily need a back port. I have not seen > reports of people experiencing this race and seeing the BUG (on mm > tear-down). > > zhongjiang, did someone actually hit the BUG? Or, did you find it by > code examination? > just code examination.
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Re: [PATCH] mm: fix account pmd page to the process Michal Hocko <mhocko@kernel.org> - 2016-06-16 17:50 +0200
Re: [PATCH] mm: fix account pmd page to the process Michal Hocko <mhocko@kernel.org> - 2016-06-16 17:50 +0200
Re: [PATCH] mm: fix account pmd page to the process Mike Kravetz <mike.kravetz@oracle.com> - 2016-06-16 18:10 +0200
Re: [PATCH] mm: fix account pmd page to the process Michal Hocko <mhocko@kernel.org> - 2016-06-16 18:40 +0200
Re: [PATCH] mm: fix account pmd page to the process Mike Kravetz <mike.kravetz@oracle.com> - 2016-06-16 18:50 +0200
Re: [PATCH] mm: fix account pmd page to the process "Kirill A. Shutemov" <kirill@shutemov.name> - 2016-06-17 14:30 +0200
Re: [PATCH] mm: fix account pmd page to the process Michal Hocko <mhocko@kernel.org> - 2016-06-17 15:10 +0200
Re: [PATCH] mm: fix account pmd page to the process "Kirill A. Shutemov" <kirill@shutemov.name> - 2016-06-17 16:30 +0200
Re: [PATCH] mm: fix account pmd page to the process Mike Kravetz <mike.kravetz@oracle.com> - 2016-06-17 17:40 +0200
Re: [PATCH] mm: fix account pmd page to the process zhong jiang <zhongjiang@huawei.com> - 2016-06-18 07:10 +0200
Re: [PATCH] mm: fix account pmd page to the process zhong jiang <zhongjiang@huawei.com> - 2016-06-17 13:20 +0200
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