From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sebastian Andrzej Siewior Date: Wed, 07 Sep 2016 13:58:55 +0000 Subject: Re: [PATCH 02/21] ARM: shmobile: Convert to hotplug state machine Message-Id: <20160907135855.wl6jbcucua5pgtac@linutronix.de> List-Id: References: <20160906170457.32393-1-bigeasy@linutronix.de> <20160906170457.32393-3-bigeasy@linutronix.de> In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-arm-kernel@lists.infradead.org On 2016-09-06 20:05:37 [+0200], Geert Uytterhoeven wrote: > Hi Sebastian, Hi Geert, > Please describe why this is desirable. We have now an old and new infrastructure in place to handle hotplug notifications while a CPU goes up and/or down. We want to get rid of the old infrastructure and are converting its users away. > > diff --git a/include/linux/cpuhotplug.h b/include/linux/cpuhotplug.h > > index 0da071ff36d2..008eed0c0787 100644 > > --- a/include/linux/cpuhotplug.h > > +++ b/include/linux/cpuhotplug.h > > @@ -35,6 +35,7 @@ enum cpuhp_state { > > CPUHP_POWERPC_PMAC_PREPARE, > > CPUHP_POWERPC_MMU_CTX_PREPARE, > > CPUHP_NOTIFY_PREPARE, > > + CPUHP_ARM_SHMOBILE_SCU_PREPARE, > > CPUHP_TIMERS_DEAD, > > CPUHP_BRINGUP_CPU, > > CPUHP_AP_IDLE_DEAD, > > What's the rationale behind adding all these numbers and always > iterating over all > of them, even though most/all of them cannot be used at the same time > (e.g. CPUHP_SH_SH3X_PREPARE is for SuperH, while > CPUHP_ARM_SHMOBILE_SCU_PREPARE is for ARM)? PREPARE + STARTING states require static ids. The online callback has dynamic allocations of ids since it was assumed that this is the most common one. We will most likely evaluate the situation once we done and total number of IDS are not acceptable. > > Gr{oetje,eeting}s, > > Geert > Sebastian From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756894AbcIGN7Y (ORCPT ); Wed, 7 Sep 2016 09:59:24 -0400 Received: from Galois.linutronix.de ([146.0.238.70]:39815 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753899AbcIGN7W (ORCPT ); Wed, 7 Sep 2016 09:59:22 -0400 Date: Wed, 7 Sep 2016 15:58:55 +0200 From: Sebastian Andrzej Siewior To: Geert Uytterhoeven Cc: "linux-kernel@vger.kernel.org" , Peter Zijlstra , Ingo Molnar , rt@linutronix.de, Thomas Gleixner , Simon Horman , Magnus Damm , "linux-arm-kernel@lists.infradead.org" , Linux-sh list , Linux-Renesas Subject: Re: [PATCH 02/21] ARM: shmobile: Convert to hotplug state machine Message-ID: <20160907135855.wl6jbcucua5pgtac@linutronix.de> References: <20160906170457.32393-1-bigeasy@linutronix.de> <20160906170457.32393-3-bigeasy@linutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: User-Agent: NeoMutt/ (1.7.0) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2016-09-06 20:05:37 [+0200], Geert Uytterhoeven wrote: > Hi Sebastian, Hi Geert, > Please describe why this is desirable. We have now an old and new infrastructure in place to handle hotplug notifications while a CPU goes up and/or down. We want to get rid of the old infrastructure and are converting its users away. > > diff --git a/include/linux/cpuhotplug.h b/include/linux/cpuhotplug.h > > index 0da071ff36d2..008eed0c0787 100644 > > --- a/include/linux/cpuhotplug.h > > +++ b/include/linux/cpuhotplug.h > > @@ -35,6 +35,7 @@ enum cpuhp_state { > > CPUHP_POWERPC_PMAC_PREPARE, > > CPUHP_POWERPC_MMU_CTX_PREPARE, > > CPUHP_NOTIFY_PREPARE, > > + CPUHP_ARM_SHMOBILE_SCU_PREPARE, > > CPUHP_TIMERS_DEAD, > > CPUHP_BRINGUP_CPU, > > CPUHP_AP_IDLE_DEAD, > > What's the rationale behind adding all these numbers and always > iterating over all > of them, even though most/all of them cannot be used at the same time > (e.g. CPUHP_SH_SH3X_PREPARE is for SuperH, while > CPUHP_ARM_SHMOBILE_SCU_PREPARE is for ARM)? PREPARE + STARTING states require static ids. The online callback has dynamic allocations of ids since it was assumed that this is the most common one. We will most likely evaluate the situation once we done and total number of IDS are not acceptable. > > Gr{oetje,eeting}s, > > Geert > Sebastian From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Return-Path: Date: Wed, 7 Sep 2016 15:58:55 +0200 From: Sebastian Andrzej Siewior To: Geert Uytterhoeven Cc: "linux-kernel@vger.kernel.org" , Peter Zijlstra , Ingo Molnar , rt@linutronix.de, Thomas Gleixner , Simon Horman , Magnus Damm , "linux-arm-kernel@lists.infradead.org" , Linux-sh list , Linux-Renesas Subject: Re: [PATCH 02/21] ARM: shmobile: Convert to hotplug state machine Message-ID: <20160907135855.wl6jbcucua5pgtac@linutronix.de> References: <20160906170457.32393-1-bigeasy@linutronix.de> <20160906170457.32393-3-bigeasy@linutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org List-ID: On 2016-09-06 20:05:37 [+0200], Geert Uytterhoeven wrote: > Hi Sebastian, Hi Geert, > Please describe why this is desirable. We have now an old and new infrastructure in place to handle hotplug notifications while a CPU goes up and/or down. We want to get rid of the old infrastructure and are converting its users away. > > diff --git a/include/linux/cpuhotplug.h b/include/linux/cpuhotplug.h > > index 0da071ff36d2..008eed0c0787 100644 > > --- a/include/linux/cpuhotplug.h > > +++ b/include/linux/cpuhotplug.h > > @@ -35,6 +35,7 @@ enum cpuhp_state { > > CPUHP_POWERPC_PMAC_PREPARE, > > CPUHP_POWERPC_MMU_CTX_PREPARE, > > CPUHP_NOTIFY_PREPARE, > > + CPUHP_ARM_SHMOBILE_SCU_PREPARE, > > CPUHP_TIMERS_DEAD, > > CPUHP_BRINGUP_CPU, > > CPUHP_AP_IDLE_DEAD, > > What's the rationale behind adding all these numbers and always > iterating over all > of them, even though most/all of them cannot be used at the same time > (e.g. CPUHP_SH_SH3X_PREPARE is for SuperH, while > CPUHP_ARM_SHMOBILE_SCU_PREPARE is for ARM)? PREPARE + STARTING states require static ids. The online callback has dynamic allocations of ids since it was assumed that this is the most common one. We will most likely evaluate the situation once we done and total number of IDS are not acceptable. > > Gr{oetje,eeting}s, > > Geert > Sebastian From mboxrd@z Thu Jan 1 00:00:00 1970 From: bigeasy@linutronix.de (Sebastian Andrzej Siewior) Date: Wed, 7 Sep 2016 15:58:55 +0200 Subject: [PATCH 02/21] ARM: shmobile: Convert to hotplug state machine In-Reply-To: References: <20160906170457.32393-1-bigeasy@linutronix.de> <20160906170457.32393-3-bigeasy@linutronix.de> Message-ID: <20160907135855.wl6jbcucua5pgtac@linutronix.de> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 2016-09-06 20:05:37 [+0200], Geert Uytterhoeven wrote: > Hi Sebastian, Hi Geert, > Please describe why this is desirable. We have now an old and new infrastructure in place to handle hotplug notifications while a CPU goes up and/or down. We want to get rid of the old infrastructure and are converting its users away. > > diff --git a/include/linux/cpuhotplug.h b/include/linux/cpuhotplug.h > > index 0da071ff36d2..008eed0c0787 100644 > > --- a/include/linux/cpuhotplug.h > > +++ b/include/linux/cpuhotplug.h > > @@ -35,6 +35,7 @@ enum cpuhp_state { > > CPUHP_POWERPC_PMAC_PREPARE, > > CPUHP_POWERPC_MMU_CTX_PREPARE, > > CPUHP_NOTIFY_PREPARE, > > + CPUHP_ARM_SHMOBILE_SCU_PREPARE, > > CPUHP_TIMERS_DEAD, > > CPUHP_BRINGUP_CPU, > > CPUHP_AP_IDLE_DEAD, > > What's the rationale behind adding all these numbers and always > iterating over all > of them, even though most/all of them cannot be used at the same time > (e.g. CPUHP_SH_SH3X_PREPARE is for SuperH, while > CPUHP_ARM_SHMOBILE_SCU_PREPARE is for ARM)? PREPARE + STARTING states require static ids. The online callback has dynamic allocations of ids since it was assumed that this is the most common one. We will most likely evaluate the situation once we done and total number of IDS are not acceptable. > > Gr{oetje,eeting}s, > > Geert > Sebastian