Message-ID: <c61a6f30-ed62-7773-3371-981102f6804f@redhat.com>
Date:   Tue, 23 Nov 2021 18:20:02 +0100
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Subject: Re: [PATCH] mm: split thp synchronously on MADV_DONTNEED
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To:     Shakeel Butt <shakeelb@google.com>
Cc:     "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>,
        Yang Shi <shy828301@gmail.com>, Zi Yan <ziy@nvidia.com>,
        Matthew Wilcox <willy@infradead.org>,
        Andrew Morton <akpm@linux-foundation.org>, linux-mm@kvack.org,
        linux-kernel@vger.kernel.org
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From:   David Hildenbrand <david@redhat.com>
Organization: Red Hat
In-Reply-To: <CALvZod4C1V6Gk96oMCMguaqChjggH0KH3KKcU1QOmjRG+QEAbQ@mail.gmail.com>
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On 23.11.21 18:17, Shakeel Butt wrote:
> On Tue, Nov 23, 2021 at 8:57 AM David Hildenbrand <david@redhat.com> wrote:
>>
> [...]
>>>>
>>>> I do wonder which these locking contexts are exactly, and if we could
>>>> also do the same thing on ordinary munmap -- because I assume it can be
>>>> similarly problematic for some applications.
>>>
>>> This is a good question regarding munmap. One main difference is
>>> munmap takes mmap_lock in write mode and usually performance critical
>>> applications avoid such operations.
>>
>> Maybe we can extend it too most page zapping, if that makes things simpler.
>>
> 
> Do you mean doing sync THP split for most of page zapping functions
> (but only if that makes things simpler)?
> 

Yes -- if there are no downsides.

-- 
Thanks,

David / dhildenb