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Subject: Re: [PATCH v18 15/32] mm/lru: move lock into lru_note_cost
To:     Hugh Dickins <hughd@google.com>
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From:   Alex Shi <alex.shi@linux.alibaba.com>
Message-ID: <323ae796-a547-3ac3-b4fd-68a4ac180690@linux.alibaba.com>
Date:   Tue, 22 Sep 2020 11:39:05 +0800
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?? 2020/9/22 ????6:03, Hugh Dickins д??:
>> Acked-by: Hugh Dickins <hughd@google.com>
>>
>> In your lruv19 github tree, you have merged 14/32 into this one: thanks.
> Grr, I've only just started, and already missed some of my notes.
> 
> I wanted to point out that this patch does introduce an extra unlock+lock
> in shrink_inactive_list(), even in a !CONFIG_MEMCG build.  I think you've
> done the right thing for now, keeping it simple, and maybe nobody will
> notice the extra overhead; but I expect us to replace lru_note_cost()
> by lru_note_cost_unlock_irq() later on, expecting the caller to do the
> initial lock_irq().
> 
> lru_note_cost_page() looks redundant to me, but you're right not to
> delete it here, unless Johannes asks you to add that in: that's his
> business, and it may be dependent on the XXX at its callsite.
> 

Thanks for comments! And got your point. so I will leave this patch alone.

Thanks!