Re: [PATCH tip/locking/core v9 4/6] locking/pvqspinlock: Collect slowpath lock statistics

From: Waiman Long <waiman.long@hpe.com>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@redhat.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	"H. Peter Anvin" <hpa@zytor.com>,
	x86@kernel.org, linux-kernel@vger.kernel.org,
	Scott J Norton <scott.norton@hpe.com>,
	Douglas Hatch <doug.hatch@hpe.com>,
	Davidlohr Bueso <dave@stgolabs.net>
Subject: Re: [PATCH tip/locking/core v9 4/6] locking/pvqspinlock: Collect slowpath lock statistics
Date: Thu, 05 Nov 2015 12:34:53 -0500	[thread overview]
Message-ID: <563B933D.8010107@hpe.com> (raw)
In-Reply-To: <20151105170911.GK3604@twins.programming.kicks-ass.net>

On 11/05/2015 12:09 PM, Peter Zijlstra wrote:
> On Thu, Nov 05, 2015 at 11:59:21AM -0500, Waiman Long wrote:
>>> Mostly I just wanted to point out that it was possible; you need not
>>> change to sysfs because debugfs lacks the capability.
>>>
>>> But now that you ask, I think debugfs might be the better place, such
>>> statistics (and the proposed CONFIG symbol) are purely for debug
>>> purposes, right?
>> Davidlohr had asked me to use per-cpu counters to reduce performance
>> overhead so that they can be usable in production system. That is another
>> reason why I move to sysfs.
> Yes, the per-cpu thing certainly makes sense. But as said, that does not
> require you to move to sysfs.
>
>> BTW, do you have comments on the other patches in the series? I would like
>> to collect all the comments before I renew the series.
> I still have to look at the last two patches, I've sadly not had time
> for that yet.

That is what I thought. Just let me know when you are done with the 
review, and I will update the patches and send out a new series.

Cheers,
Longman