Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1162205AbbKERJX (ORCPT ); Thu, 5 Nov 2015 12:09:23 -0500 Received: from bombadil.infradead.org ([198.137.202.9]:51428 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1030549AbbKERJW (ORCPT ); Thu, 5 Nov 2015 12:09:22 -0500 Date: Thu, 5 Nov 2015 18:09:11 +0100 From: Peter Zijlstra To: Waiman Long Cc: Ingo Molnar , Thomas Gleixner , "H. Peter Anvin" , x86@kernel.org, linux-kernel@vger.kernel.org, Scott J Norton , Douglas Hatch , Davidlohr Bueso Subject: Re: [PATCH tip/locking/core v9 4/6] locking/pvqspinlock: Collect slowpath lock statistics Message-ID: <20151105170911.GK3604@twins.programming.kicks-ass.net> References: <1446247597-61863-1-git-send-email-Waiman.Long@hpe.com> <1446247597-61863-5-git-send-email-Waiman.Long@hpe.com> <20151102164040.GV3604@twins.programming.kicks-ass.net> <563B83E9.60909@hpe.com> <20151105164322.GH3604@twins.programming.kicks-ass.net> <563B8AE9.1040000@hpe.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <563B8AE9.1040000@hpe.com> User-Agent: Mutt/1.5.21 (2012-12-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1104 Lines: 25 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. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/