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Date: Tue, 12 Jul 2016 15:42:33 -0400
From: Waiman Long <waiman.long@hpe.com>
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To: Tejun Heo <tj@kernel.org>
CC: Alexander Viro <viro@zeniv.linux.org.uk>, Jan Kara <jack@suse.com>,
	Jeff Layton <jlayton@poochiereds.net>,
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	Andi Kleen <andi@firstfloor.org>,
	Dave Chinner <dchinner@redhat.com>,
	Boqun Feng <boqun.feng@gmail.com>,
	Scott J Norton <scott.norton@hpe.com>,
	Douglas Hatch <doug.hatch@hpe.com>
Subject: Re: [RFC PATCH v2 6/7] lib/persubnode: Introducing a simple per-subnode
 APIs
References: <1468258332-61537-1-git-send-email-Waiman.Long@hpe.com> <1468258332-61537-7-git-send-email-Waiman.Long@hpe.com> <20160712142727.GA3190@htj.duckdns.org> <57853C33.8000705@hpe.com> <20160712185718.GH3190@htj.duckdns.org>
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On 07/12/2016 02:57 PM, Tejun Heo wrote:
> Hello,
>
> On Tue, Jul 12, 2016 at 02:51:31PM -0400, Waiman Long wrote:
>> The last 2 RFC patches were created in response to Andi's comment to have
>> coarser granularity than per-cpu. In this particular use case, I don't think
>> global list traversals are frequent enough to really have any noticeable
>> performance impact. So I don't have any benchmark number to support this
>> change. However, it may not be true for other future use cases.
>>
>> These 2 patches were created to gauge if using a per-subnode API for this
>> use case is a good idea or not. I am perfectly happy to keep it as per-cpu
>> and scrap the last 2 RFC patches. My main goal is to make this patchset more
>> acceptable to be moved forward instead of staying in limbo.
> I see.  I don't think it makes sense to add a whole new API for a use
> case which doesn't really need it without any backing data.  It
> probably would be best to revisit this when we're dealing with an
> actually problematic case.
>
> Thanks.
>

I am fine with that. BTW, do you think patches 1-5 are good enough to be 
merged in a future release or is there further improvement that needs to 
be made?

Thanks,
Longman