From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kevin Hilman Subject: Re: [PATCH RFC idle 2/3] arm: Avoid invoking RCU when CPU is idle Date: Thu, 02 Feb 2012 14:20:26 -0800 Message-ID: <87obtgc1xx.fsf@ti.com> References: <20120202004253.GA10946@linux.vnet.ibm.com> <1328143404-11038-1-git-send-email-paulmck@linux.vnet.ibm.com> <1328143404-11038-2-git-send-email-paulmck@linux.vnet.ibm.com> <20120202044439.GD2435@linux.vnet.ibm.com> <20120202174337.GS2518@linux.vnet.ibm.com> <20120202190708.GE2518@linux.vnet.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20120202190708.GE2518@linux.vnet.ibm.com> (Paul E. McKenney's message of "Thu, 2 Feb 2012 11:07:08 -0800") List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linux-arm-kernel-bounces@lists.infradead.org Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=m.gmane.org@lists.infradead.org To: paulmck@linux.vnet.ibm.com Cc: Nicolas Pitre , mathieu.desnoyers@polymtl.ca, peterz@infradead.org, fweisbec@gmail.com, Nicolas Ferre , dhowells@redhat.com, Lennert Buytenhek , Kukjin Kim , Russell King , eric.dumazet@gmail.com, "Paul E. McKenney" , Magnus Damm , Tony Lindgren , dipankar@in.ibm.com, darren@dvhart.com, mingo@elte.hu, Jean-Christophe Plagniol-Villard , Len Brown , Amit Kucheria , patches@linaro.org, Will Deacon , josh@joshtriplett.org, Sekhar Nori , niv@us.ibm.com, linux-samsung-soc@vger.kernel.org, rostedt@goodmis.org, Barry Song , tglx@linutronix.de, linux-omap@vger.kerne List-Id: linux-omap@vger.kernel.org "Paul E. McKenney" writes: [...] >> > The two options I see are: >> > >> > 1. Rip tracing out of the inner idle loops and everything that >> > they invoke. >> >> What I suggested above. But as I said I know sh*t about that tracing >> implementation so that's an easy suggestion for me to make. > > Works for me as well. ;-) While I must admit not having a better suggestion, I for one would vote strongly against removing tracing from the idle path. Being a PM developer and maintainer, much of the code I work on and maintain happens to be run in the bowels of the idle path. Not having the ability to trace this code would be a major step backwards IMO. Kevin From mboxrd@z Thu Jan 1 00:00:00 1970 From: khilman@ti.com (Kevin Hilman) Date: Thu, 02 Feb 2012 14:20:26 -0800 Subject: [PATCH RFC idle 2/3] arm: Avoid invoking RCU when CPU is idle In-Reply-To: <20120202190708.GE2518@linux.vnet.ibm.com> (Paul E. McKenney's message of "Thu, 2 Feb 2012 11:07:08 -0800") References: <20120202004253.GA10946@linux.vnet.ibm.com> <1328143404-11038-1-git-send-email-paulmck@linux.vnet.ibm.com> <1328143404-11038-2-git-send-email-paulmck@linux.vnet.ibm.com> <20120202044439.GD2435@linux.vnet.ibm.com> <20120202174337.GS2518@linux.vnet.ibm.com> <20120202190708.GE2518@linux.vnet.ibm.com> Message-ID: <87obtgc1xx.fsf@ti.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org "Paul E. McKenney" writes: [...] >> > The two options I see are: >> > >> > 1. Rip tracing out of the inner idle loops and everything that >> > they invoke. >> >> What I suggested above. But as I said I know sh*t about that tracing >> implementation so that's an easy suggestion for me to make. > > Works for me as well. ;-) While I must admit not having a better suggestion, I for one would vote strongly against removing tracing from the idle path. Being a PM developer and maintainer, much of the code I work on and maintain happens to be run in the bowels of the idle path. Not having the ability to trace this code would be a major step backwards IMO. Kevin