From: Mel Gorman <mgorman@techsingularity.net>
To: Zhenhua Huang <quic_zhenhuah@quicinc.com>
Cc: akpm@linux-foundation.org, linux-mm@kvack.org, quic_tingweiz@quicinc.com
Subject: Re: [PATCH v2] mm/page_owner.c: remove redudant drain_all_pages
Date: Thu, 8 Sep 2022 15:55:38 +0100 [thread overview]
Message-ID: <20220908145538.in2ttdaejp2zxwxk@techsingularity.net> (raw)
In-Reply-To: <1662633204-10044-1-git-send-email-quic_zhenhuah@quicinc.com>
On Thu, Sep 08, 2022 at 06:33:24PM +0800, Zhenhua Huang wrote:
> Remove an expensive and unnecessary operation as PCP pages are safely
> skipped when reading page owner. PCP pages can be skipped because
> PAGE_EXT_OWNER_ALLOCATED is cleared.
>
> With draining PCP pages, these pages are moved to buddy list so they
> can be identified as buddy pages and skipped quickly. Although it improved
> efficiency of PFN walker, the drain is guaranteed expensive that is
> unlikely to be offset by a slight increase in efficiency when skipping
> free pages.
>
> PAGE_EXT_OWNER_ALLOCATED is cleared in the page owner reset path below:
> free_unref_page
> -> free_unref_page_prepare
> -> free_pcp_prepare
> -> free_pages_prepare which do page owner
> reset
> -> free_unref_page_commit which add pages into pcp list
>
> Acked-by: Mel Gorman <mgorman@techsingularity.net>
> Signed-off-by: Zhenhua Huang <quic_zhenhuah@quicinc.com>
Should be;
Signed-off-by: Zhenhua Huang <quic_zhenhuah@quicinc.com>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Otherwise looks good!
--
Mel Gorman
SUSE Labs
next prev parent reply other threads:[~2022-09-08 15:02 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-09-08 10:33 [PATCH v2] mm/page_owner.c: remove redudant drain_all_pages Zhenhua Huang
2022-09-08 14:55 ` Mel Gorman [this message]
2022-09-09 6:18 ` Zhenhua Huang
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