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From:   Shakeel Butt <shakeelb@google.com>
Date:   Tue, 23 Nov 2021 09:17:16 -0800
Message-ID: <CALvZod4C1V6Gk96oMCMguaqChjggH0KH3KKcU1QOmjRG+QEAbQ@mail.gmail.com>
Subject: Re: [PATCH] mm: split thp synchronously on MADV_DONTNEED
To:     David Hildenbrand <david@redhat.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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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)?