From: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
To: Wei Yang <richardw.yang@linux.intel.com>,
Li Xinhai <lixinhai.lxh@gmail.com>
Cc: "linux-mm@kvack.org" <linux-mm@kvack.org>,
akpm <akpm@linux-foundation.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
Rik van Riel <riel@redhat.com>,
"kirill.shutemov" <kirill.shutemov@linux.intel.com>
Subject: Re: [PATCH v2 1/2] mm/rmap: fix and simplify reusing mergeable anon_vma as parent when fork
Date: Sat, 18 Jan 2020 11:04:21 +0300 [thread overview]
Message-ID: <8f335403-4a14-bd17-39da-6299dd962fc6@yandex-team.ru> (raw)
In-Reply-To: <20200115012055.GC4916@richard>
On 15/01/2020 04.20, Wei Yang wrote:
> On Tue, Jan 14, 2020 at 10:42:52PM +0800, Li Xinhai wrote:
>> On 2020-01-13 at 19:07 Konstantin Khlebnikov wrote:
>>
>>>
>>> Because I want to keep both heuristics.
>>> This seems most sane way of interaction between them.
>>>
>>> Unfortunately even this patch is slightly broken.
>>> Condition prev->anon_vma->parent == pvma->anon_vma doesn't guarantee that
>>> prev vma has the same set of anon-vmas like current vma.
>>> I.e. anon_vma_clone(vma, prev) might be not enough for keeping connectivity.
>>
>> New patch is required?
>
> My suggestion is separate the fix and new approach instead of mess them into
> one patch.
Yep, it's messy. Maybe it's could be better to revert recent change,
apply second patch from this set and write something new after that.
>
>> It is necessary to call anon_vma_clone(vma, pvma) to link all anon_vma which
>> currently linked by pvma, then link the prev->anon_vma to vma. By this way,
>> connectivity of vma should be maintained, right?
>>
>>> Building such case isn't trivial job but I see nothing that could prevent it.
>>>
>>
>
next prev parent reply other threads:[~2020-01-18 8:04 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-01-07 10:19 [PATCH v2 1/2] mm/rmap: fix and simplify reusing mergeable anon_vma as parent when fork Konstantin Khlebnikov
2020-01-07 10:19 ` [PATCH v2 2/2] kernel/fork: set VMA's mm/prev/next right after vm_area_dup in dup_mmap Konstantin Khlebnikov
2020-01-08 2:32 ` [PATCH v2 1/2] mm/rmap: fix and simplify reusing mergeable anon_vma as parent when fork Wei Yang
2020-01-08 10:40 ` Konstantin Khlebnikov
2020-01-09 2:52 ` Wei Yang
2020-01-09 8:54 ` Konstantin Khlebnikov
2020-01-10 2:30 ` Wei Yang
[not found] ` <20200110112357351531132@gmail.com>
2020-01-10 5:34 ` Wei Yang
2020-01-10 8:11 ` Konstantin Khlebnikov
2020-01-11 22:38 ` Wei Yang
2020-01-12 9:55 ` Konstantin Khlebnikov
2020-01-13 0:33 ` Wei Yang
2020-01-13 11:07 ` Konstantin Khlebnikov
2020-01-14 2:09 ` Wei Yang
[not found] ` <2020011422424965556826@gmail.com>
2020-01-15 1:20 ` Wei Yang
2020-01-18 8:04 ` Konstantin Khlebnikov [this message]
2020-01-18 14:00 ` Wei Yang
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