Re: [PATCH v3 2/7] mm/lruvec: add irqsave flags into lruvec struct

From: Alex Shi <alex.shi@linux.alibaba.com>
To: Shakeel Butt <shakeelb@google.com>
Cc: Cgroups <cgroups@vger.kernel.org>,
	LKML <linux-kernel@vger.kernel.org>,
	Linux MM <linux-mm@kvack.org>,
	Andrew Morton <akpm@linux-foundation.org>,
	Mel Gorman <mgorman@techsingularity.net>,
	Tejun Heo <tj@kernel.org>, Hugh Dickins <hughd@google.com>,
	Konstantin Khlebnikov <khlebnikov@yandex-team.ru>,
	Daniel Jordan <daniel.m.jordan@oracle.com>,
	Yang Shi <yang.shi@linux.alibaba.com>,
	Matthew Wilcox <willy@infradead.org>,
	Vlastimil Babka <vbabka@suse.cz>,
	Dan Williams <dan.j.williams@intel.com>,
	Michal Hocko <mhocko@suse.com>,
	Wei Yang <richard.weiyang@gmail.com>,
	Johannes Weiner <hannes@cmpxchg.org>,
	Arun KS <arunks@codeaurora.org>,
	Rong Chen <rong.a.chen@intel.com>
Subject: Re: [PATCH v3 2/7] mm/lruvec: add irqsave flags into lruvec struct
Date: Mon, 18 Nov 2019 10:52:40 +0800	[thread overview]
Message-ID: <de24def3-3593-a2f7-ab73-5ac379c1e5ca@linux.alibaba.com> (raw)
In-Reply-To: <CALvZod5xuetOb8Vunhgjp69-HcrnHgGHZKKyjVBo3tmoc3WqaA@mail.gmail.com>

在 2019/11/16 下午2:31, Shakeel Butt 写道:
> On Fri, Nov 15, 2019 at 7:15 PM Alex Shi <alex.shi@linux.alibaba.com> wrote:
>> We need a irqflags vaiable to save state when do irqsave action, declare
>> it here would make code more clear/clean.
>>
>> Rong Chen <rong.a.chen@intel.com> reported the 'irqflags' variable need
>> move to the tail of lruvec struct otherwise it causes 18% regressions of
>> vm-scalability testing on his machine. So add the flags and lru_lock to
>> both near struct tail, even I have no clue of this perf losing.
> Regressions compared to what? Also no need to have a separate patch.
> 

Thanks for question, Shakeel, 
I will change the commit log and mention the original place: the head of lruvec struct.
As to the folding, the 3rd is already toooo long. May I leave it here to relief a littel bit burden on reading?

Thanks
Alex