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Subject: Re: [PATCH] mm/vmstat: don't do count if no needs
To:     Andrew Morton <akpm@linux-foundation.org>
Cc:     linux-mm@kvack.org, linux-kernel@vger.kernel.org
References: <20200720052348.428564-1-alex.shi@linux.alibaba.com>
 <1ef9baa0-9788-5917-2590-a8c3fc593b81@linux.alibaba.com>
 <20200720161404.bd0c24560114bf48d6acbaff@linux-foundation.org>
From:   Alex Shi <alex.shi@linux.alibaba.com>
Message-ID: <757accf7-81bf-442c-f144-4cad52fea4a5@linux.alibaba.com>
Date:   Tue, 21 Jul 2020 11:07:48 +0800
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?? 2020/7/21 ????7:14, Andrew Morton д??:
>> --- a/mm/vmstat.c
>> +++ b/mm/vmstat.c
>> @@ -321,6 +321,9 @@ void __mod_zone_page_state(struct zone *zone, enum zone_stat_item item,
>>  	long x;
>>  	long t;
>>  
>> +	if (unlikely(!delta))
>> +		return;
>> +
> Do we know that delta==0 is frequent enough to make the change a net
> benefit?

Uh,I check again. it seems no much place delta==0, forget this patch.

Thanks
Alex