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From: Michal Hocko <mhocko@suse.com>
To: Lance Yang <ioworker0@gmail.com>
Cc: akpm@linux-foundation.org, zokeefe@google.com, david@redhat.com,
	songmuchun@bytedance.com, shy828301@gmail.com, peterx@redhat.com,
	minchan@kernel.org, linux-mm@kvack.org,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH 1/1] mm/khugepaged: bypassing unnecessary scans with MMF_DISABLE_THP check
Date: Mon, 29 Jan 2024 17:28:47 +0100	[thread overview]
Message-ID: <ZbfSP6xt6JAE2NrH@tiehlicka> (raw)
In-Reply-To: <20240129054551.57728-1-ioworker0@gmail.com>

On Mon 29-01-24 13:45:51, Lance Yang wrote:
> khugepaged scans the entire address space in the
> background for each given mm, looking for
> opportunities to merge sequences of basic pages
> into huge pages. However, when an mm is inserted
> to the mm_slots list, and the MMF_DISABLE_THP flag
> is set later, this scanning process becomes
> unnecessary for that mm and can be skipped to avoid
> redundant operations, especially in scenarios with
> a large address space.

Is this a real problem? I thought that the prctl is called
on the parent before fork/exec. Or are you aware of any
applications which do call prctl late enough that the race
would be actually observable?
-- 
Michal Hocko
SUSE Labs

  reply	other threads:[~2024-01-29 16:28 UTC|newest]

Thread overview: 28+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-01-29  5:45 [PATCH 1/1] mm/khugepaged: bypassing unnecessary scans with MMF_DISABLE_THP check Lance Yang
2024-01-29 16:28 ` Michal Hocko [this message]
2024-01-30  2:12   ` Lance Yang
2024-01-30  3:08     ` Lance Yang
2024-01-30  9:35       ` Michal Hocko
2024-01-30  9:46         ` Lance Yang
2024-01-31  0:37           ` Lance Yang
2024-01-29 18:53 ` Yang Shi
2024-01-29 19:03   ` Zach O'Keefe
2024-01-30  2:37     ` Lance Yang
2024-01-30  2:21   ` Lance Yang
2024-01-31  9:30 ` Lance Yang
2024-01-31 20:06   ` Yang Shi
2024-02-01  1:13     ` Lance Yang
2024-02-01 18:56       ` Yang Shi
2024-02-03  3:20         ` Lance Yang
2024-02-21 22:11   ` Andrew Morton
2024-02-22  7:43     ` Lance Yang
2024-02-22  7:51   ` Lance Yang
2024-02-22  8:51     ` David Hildenbrand
2024-02-22  9:12       ` Lance Yang
2024-02-22 20:23     ` Yang Shi
2024-02-22 21:11       ` Andrew Morton
2024-02-23  7:59         ` Lance Yang
2024-02-24  1:47         ` Yang Shi
2024-02-24  1:46 ` Yang Shi
2024-02-24  3:54   ` Lance Yang
2024-02-25  4:56     ` Lance Yang

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