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Subject: Re: [PATCH v3 3/7] mm/lru: replace pgdat lru_lock with lruvec lock
To:     Daniel Jordan <daniel.m.jordan@oracle.com>
Cc:     cgroups@vger.kernel.org, linux-kernel@vger.kernel.org,
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        "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>,
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 <20191119021058.auxc6g7vmgf7d5gg@ca-dmjordan1.us.oracle.com>
From:   Alex Shi <alex.shi@linux.alibaba.com>
Message-ID: <1199177d-6f34-3aae-3eb6-8fac42f070a1@linux.alibaba.com>
Date:   Tue, 19 Nov 2019 18:10:09 +0800
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?? 2019/11/19 ????10:10, Daniel Jordan д??:
>> -	if (pgdat)
>> -		spin_unlock_irqrestore(&pgdat->lru_lock, flags);
>> +
>>  	release_pages(pvec->pages, pvec->nr);
>>  	pagevec_reinit(pvec);
>>  }
> Why can't you keep the locking pattern where we only drop and reacquire if the
> lruvec changes?  It'd save a lot of locks and unlocks if most pages were from
> the same memcg and node, or the memory controller were unused.
> 

Good catching! This issue will be fixed in the next patch which introduce relock_ function.

Thanks!