Message-ID: <7962d171-fc29-88db-ee33-4326838d7b40@suse.cz>
Date:   Tue, 7 Feb 2023 17:53:39 +0100
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Subject: Re: [PATCH 2/4] mm, compaction: Check if a page has been captured
 before draining PCP pages
Content-Language: en-US
To:     Mel Gorman <mgorman@techsingularity.net>
Cc:     Andrew Morton <akpm@linux-foundation.org>,
        Jiri Slaby <jirislaby@kernel.org>,
        Maxim Levitsky <mlevitsk@redhat.com>,
        Michal Hocko <mhocko@kernel.org>,
        Pedro Falcato <pedro.falcato@gmail.com>,
        Paolo Bonzini <pbonzini@redhat.com>,
        Chuyi Zhou <zhouchuyi@bytedance.com>,
        Linux-MM <linux-mm@kvack.org>,
        LKML <linux-kernel@vger.kernel.org>
References: <20230125134434.18017-1-mgorman@techsingularity.net>
 <20230125134434.18017-3-mgorman@techsingularity.net>
From:   Vlastimil Babka <vbabka@suse.cz>
In-Reply-To: <20230125134434.18017-3-mgorman@techsingularity.net>
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Precedence: bulk

On 1/25/23 14:44, Mel Gorman wrote:
> If a page has been captured then draining is unnecssary so check first
> for a captured page.
> 
> Signed-off-by: Mel Gorman <mgorman@techsingularity.net>

Acked-by: Vlastimil Babka <vbabka@suse.cz>

> ---
>  mm/compaction.c | 12 ++++++------
>  1 file changed, 6 insertions(+), 6 deletions(-)
> 
> diff --git a/mm/compaction.c b/mm/compaction.c
> index c018b0e65720..28711a21a8a2 100644
> --- a/mm/compaction.c
> +++ b/mm/compaction.c
> @@ -2441,6 +2441,12 @@ compact_zone(struct compact_control *cc, struct capture_control *capc)
>  			}
>  		}
>  
> +		/* Stop if a page has been captured */
> +		if (capc && capc->page) {
> +			ret = COMPACT_SUCCESS;
> +			break;
> +		}
> +
>  check_drain:
>  		/*
>  		 * Has the migration scanner moved away from the previous
> @@ -2459,12 +2465,6 @@ compact_zone(struct compact_control *cc, struct capture_control *capc)
>  				last_migrated_pfn = 0;
>  			}
>  		}
> -
> -		/* Stop if a page has been captured */
> -		if (capc && capc->page) {
> -			ret = COMPACT_SUCCESS;
> -			break;
> -		}
>  	}
>  
>  out: