From: "Zi Yan" <zi.yan@sent.com>
To: "Naoya Horiguchi" <n-horiguchi@ah.jp.nec.com>
Cc: "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"linux-mm@kvack.org" <linux-mm@kvack.org>,
"kirill.shutemov@linux.intel.com"
<kirill.shutemov@linux.intel.com>,
"akpm@linux-foundation.org" <akpm@linux-foundation.org>,
"minchan@kernel.org" <minchan@kernel.org>,
"vbabka@suse.cz" <vbabka@suse.cz>,
"mgorman@techsingularity.net" <mgorman@techsingularity.net>,
"khandual@linux.vnet.ibm.com" <khandual@linux.vnet.ibm.com>,
"Zi Yan" <ziy@nvidia.com>
Subject: Re: [PATCH v3 01/14] mm: thp: make __split_huge_pmd_locked visible.
Date: Mon, 06 Feb 2017 06:10:17 -0600 [thread overview]
Message-ID: <47D53C68-7A1B-42AC-B526-F05A6CA48FA5@sent.com> (raw)
In-Reply-To: <20170206061232.GB1659@hori1.linux.bs1.fc.nec.co.jp>
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On 6 Feb 2017, at 0:12, Naoya Horiguchi wrote:
> On Sun, Feb 05, 2017 at 11:12:39AM -0500, Zi Yan wrote:
>> From: Zi Yan <ziy@nvidia.com>
>>
>> It allows splitting huge pmd while you are holding the pmd lock.
>> It is prepared for future zap_pmd_range() use.
>>
>> Signed-off-by: Zi Yan <zi.yan@cs.rutgers.edu>
>> ---
>> include/linux/huge_mm.h | 2 ++
>> mm/huge_memory.c | 22 ++++++++++++----------
>> 2 files changed, 14 insertions(+), 10 deletions(-)
>>
> ...
>> diff --git a/mm/huge_memory.c b/mm/huge_memory.c
>> index 03e4566fc226..cd66532ef667 100644
> ...
>> @@ -2036,10 +2039,9 @@ void __split_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd,
>> clear_page_mlock(page);
>> } else if (!pmd_devmap(*pmd))
>> goto out;
>> - __split_huge_pmd_locked(vma, pmd, haddr, freeze);
>> + __split_huge_pmd_locked(vma, pmd, address, freeze);
>
> Could you explain what is intended on this change?
> If some caller (f.e. wp_huge_pmd?) could call __split_huge_pmd() with
> address not aligned with pmd border, __split_huge_pmd_locked() results in
> triggering VM_BUG_ON(haddr & ~HPAGE_PMD_MASK).
This change is intended for any caller already hold pmd lock. Now it is for this
call site only.
In Patch 2, I moved unsigned long haddr = address & HPAGE_PMD_MASK;
from __split_huge_pmd() to __split_huge_pmd_locked(), so VM_BUG_ON(haddr & ~HPAGE_PMD_MASK)
will not be triggered.
>
> Thanks,
> Naoya Horiguchi
>
>> out:
>> spin_unlock(ptl);
>> - mmu_notifier_invalidate_range_end(mm, haddr, haddr + HPAGE_PMD_SIZE);
>> }
>>
>> void split_huge_pmd_address(struct vm_area_struct *vma, unsigned long address,
>> --
>> 2.11.0
>>
--
Best Regards
Yan Zi
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next prev parent reply other threads:[~2017-02-06 12:10 UTC|newest]
Thread overview: 47+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-02-05 16:12 [PATCH v3 00/14] mm: page migration enhancement for thp Zi Yan
2017-02-05 16:12 ` [PATCH v3 01/14] mm: thp: make __split_huge_pmd_locked visible Zi Yan
2017-02-06 6:12 ` Naoya Horiguchi
2017-02-06 12:10 ` Zi Yan [this message]
2017-02-06 15:02 ` Matthew Wilcox
2017-02-06 15:03 ` Zi Yan
2017-02-05 16:12 ` [PATCH v3 02/14] mm: thp: create new __zap_huge_pmd_locked function Zi Yan
2017-02-05 16:12 ` [PATCH v3 03/14] mm: use pmd lock instead of racy checks in zap_pmd_range() Zi Yan
2017-02-06 4:02 ` Hillf Danton
2017-02-06 4:14 ` Zi Yan
2017-02-06 7:43 ` Naoya Horiguchi
2017-02-06 13:02 ` Zi Yan
2017-02-06 23:22 ` Naoya Horiguchi
2017-02-06 16:07 ` Kirill A. Shutemov
2017-02-06 16:32 ` Zi Yan
2017-02-06 17:35 ` Kirill A. Shutemov
2017-02-07 13:55 ` Aneesh Kumar K.V
2017-02-07 14:19 ` Kirill A. Shutemov
2017-02-07 15:11 ` Zi Yan
2017-02-07 16:37 ` Kirill A. Shutemov
2017-02-07 17:14 ` Zi Yan
2017-02-07 17:45 ` Kirill A. Shutemov
2017-02-13 0:25 ` Zi Yan
2017-02-13 10:59 ` Kirill A. Shutemov
2017-02-13 14:40 ` Andrea Arcangeli
2017-02-05 16:12 ` [PATCH v3 04/14] mm: x86: move _PAGE_SWP_SOFT_DIRTY from bit 7 to bit 1 Zi Yan
2017-02-09 9:14 ` Naoya Horiguchi
2017-02-09 15:07 ` Zi Yan
2017-02-05 16:12 ` [PATCH v3 05/14] mm: mempolicy: add queue_pages_node_check() Zi Yan
2017-02-05 16:12 ` [PATCH v3 06/14] mm: thp: introduce separate TTU flag for thp freezing Zi Yan
2017-02-05 16:12 ` [PATCH v3 07/14] mm: thp: introduce CONFIG_ARCH_ENABLE_THP_MIGRATION Zi Yan
2017-02-05 16:12 ` [PATCH v3 08/14] mm: thp: enable thp migration in generic path Zi Yan
2017-02-09 9:15 ` Naoya Horiguchi
2017-02-09 15:17 ` Zi Yan
2017-02-09 23:04 ` Naoya Horiguchi
2017-02-14 20:13 ` Zi Yan
2017-02-05 16:12 ` [PATCH v3 09/14] mm: thp: check pmd migration entry in common path Zi Yan
2017-02-09 9:16 ` Naoya Horiguchi
2017-02-09 17:36 ` Zi Yan
2017-02-05 16:12 ` [PATCH v3 10/14] mm: soft-dirty: keep soft-dirty bits over thp migration Zi Yan
2017-02-05 16:12 ` [PATCH v3 11/14] mm: hwpoison: soft offline supports " Zi Yan
2017-02-05 16:12 ` [PATCH v3 12/14] mm: mempolicy: mbind and migrate_pages support " Zi Yan
2017-02-05 16:12 ` [PATCH v3 13/14] mm: migrate: move_pages() supports " Zi Yan
2017-02-09 9:16 ` Naoya Horiguchi
2017-02-09 17:37 ` Zi Yan
2017-02-05 16:12 ` [PATCH v3 14/14] mm: memory_hotplug: memory hotremove " Zi Yan
2017-02-23 16:12 ` [PATCH v3 00/14] mm: page migration enhancement for thp Zi Yan
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