From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from e34.co.us.ibm.com (e34.co.us.ibm.com [32.97.110.152]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 56F691A03D3 for ; Thu, 2 Apr 2015 23:44:28 +1100 (AEDT) Received: from /spool/local by e34.co.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Thu, 2 Apr 2015 06:44:26 -0600 Received: from b03cxnp08028.gho.boulder.ibm.com (b03cxnp08028.gho.boulder.ibm.com [9.17.130.20]) by d03dlp02.boulder.ibm.com (Postfix) with ESMTP id DEB6F3E4003B for ; Thu, 2 Apr 2015 06:44:23 -0600 (MDT) Received: from d03av04.boulder.ibm.com (d03av04.boulder.ibm.com [9.17.195.170]) by b03cxnp08028.gho.boulder.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id t32CiBHt36044988 for ; Thu, 2 Apr 2015 05:44:11 -0700 Received: from d03av04.boulder.ibm.com (loopback [127.0.0.1]) by d03av04.boulder.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id t32CiMEf017424 for ; Thu, 2 Apr 2015 06:44:23 -0600 Message-ID: <551D39A2.8020009@linux.vnet.ibm.com> Date: Thu, 02 Apr 2015 18:14:18 +0530 From: Preeti U Murthy MIME-Version: 1.0 To: Ingo Molnar , Peter Zijlstra Subject: Re: [PATCH V2] clockevents: Fix cpu down race for hrtimer based broadcasting References: <20150330092410.24979.59887.stgit@preeti.in.ibm.com> <20150402104226.GB21105@gmail.com> <20150402120256.GV23123@twins.programming.kicks-ass.net> <20150402121247.GA18104@gmail.com> In-Reply-To: <20150402121247.GA18104@gmail.com> Content-Type: text/plain; charset=UTF-8 Cc: nicolas.pitre@linaro.org, linuxppc-dev@lists.ozlabs.org, tglx@linutronix.de, rjw@rjwysocki.net, linux-kernel@vger.kernel.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On 04/02/2015 05:42 PM, Ingo Molnar wrote: > > * Peter Zijlstra wrote: > >> On Thu, Apr 02, 2015 at 12:42:27PM +0200, Ingo Molnar wrote: >>> So why not use a suitable CPU_DOWN* notifier for this, instead of open >>> coding it all into a random place in the hotplug machinery? >> >> Because notifiers are crap? ;-) [...] > > No doubt - but I didn't feel this poorly named random call into the > hotplug code, with no comments was any better. > >> [...] Its entirely impossible to figure out what's happening to core >> code in hotplug. You need to go chase down and random order notifier >> things. >> >> I'm planning on taking out many of the core hotplug notifiers and >> hard coding their callbacks into the hotplug code. > > That's very welcome news - but please also lets put in place a proper > namespace for all these callbacks, to make them easy to find and > change: hotplug_cpu__*() or so, which in this case would turn into > hotplug_cpu__tick_pull() or so? > >> That way at least its clear wtf happens when. > > Okay. I'll resurrect the fix with a hotplug_cpu__tick_pull() name - > agreed? Sounds good to me. This needs to be marked to stable also. Regards Preeti U Murthy