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: skip copying lazyfree pages on collapse
Date: Fri, 2 Feb 2024 11:06:40 +0100 [thread overview]
Message-ID: <Zby-sHLDlmTRaUcd@tiehlicka> (raw)
In-Reply-To: <20240201125226.28372-1-ioworker0@gmail.com>
On Thu 01-02-24 20:52:26, Lance Yang wrote:
> The collapsing behavior of khugepaged with pages
> marked using MADV_FREE might cause confusion
> among users.
>
> For instance, allocate a 2MB chunk using mmap and
> later release it by MADV_FREE. Khugepaged will not
> collapse this chunk. From the user's perspective,
> it treats lazyfree pages as pte_none. However,
> for some pages marked as lazyfree with MADV_FREE,
> khugepaged might collapse this chunk and copy
> these pages to a new huge page. This inconsistency
> in behavior could be confusing for users.
Is that any more confusing than collapsing pte_none
pages?
TBH I do not really see why this is a problem. MADV_FREE
are correctly recognized same as pte_none so the user
defined trashold applies.
--
Michal Hocko
SUSE Labs
next prev parent reply other threads:[~2024-02-02 10:06 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-02-01 12:52 [PATCH 1/1] mm/khugepaged: skip copying lazyfree pages on collapse Lance Yang
2024-02-01 13:49 ` Lance Yang
2024-02-01 20:37 ` Yang Shi
2024-02-02 11:23 ` Lance Yang
2024-02-02 17:43 ` Yang Shi
2024-02-02 10:06 ` Michal Hocko [this message]
2024-02-02 11:18 ` Lance Yang
2024-02-02 12:27 ` Michal Hocko
2024-02-02 12:52 ` Lance Yang
2024-02-02 12:57 ` Michal Hocko
2024-02-02 13:46 ` Lance Yang
2024-02-02 14:20 ` Lance Yang
2024-02-02 14:42 ` Michal Hocko
2024-02-02 14:52 ` Lance Yang
2024-02-02 15:26 ` David Hildenbrand
2024-02-02 15:38 ` Michal Hocko
2024-02-02 17:42 ` Yang Shi
2024-02-03 4:17 ` Lance Yang
2024-02-05 19:41 ` Yang Shi
2024-02-05 9:45 ` Michal Hocko
2024-02-05 19:43 ` Yang Shi
2024-02-05 20:26 ` Zach O'Keefe
2024-02-20 10:15 ` Lance Yang
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