Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751974AbdGFPQ0 (ORCPT ); Thu, 6 Jul 2017 11:16:26 -0400 Received: from mail-pf0-f194.google.com ([209.85.192.194]:32906 "EHLO mail-pf0-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750970AbdGFPQX (ORCPT ); Thu, 6 Jul 2017 11:16:23 -0400 Date: Fri, 7 Jul 2017 01:16:09 +1000 From: Nicholas Piggin To: "Gautham R. Shenoy" Cc: Michael Ellerman , Michael Neuling , Vaidyanathan Srinivasan , Shilpasri G Bhat , "Rafael J. Wysocki" , Akshay Adiga , linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org Subject: Re: [PATCH 4/5] powernv:idle: Move initialization of sibling pacas to pnv_alloc_idle_core_states Message-ID: <20170707011609.76c51329@roar.ozlabs.ibm.com> In-Reply-To: <1499272696-28751-5-git-send-email-ego@linux.vnet.ibm.com> References: <1499272696-28751-1-git-send-email-ego@linux.vnet.ibm.com> <1499272696-28751-5-git-send-email-ego@linux.vnet.ibm.com> Organization: IBM X-Mailer: Claws Mail 3.14.1 (GTK+ 2.24.31; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1169 Lines: 33 On Wed, 5 Jul 2017 22:08:15 +0530 "Gautham R. Shenoy" wrote: > From: "Gautham R. Shenoy" > > On POWER9 DD1, in order to get around a hardware issue, we store in > every CPU thread's paca the paca pointers of all its siblings. > > Move this code into pnv_alloc_idle_core_states() soon after the space > for saving the sibling pacas is allocated. > > Signed-off-by: Gautham R. Shenoy > - if (cpu_has_feature(CPU_FTR_POWER9_DD1)) { > - int cpu; > - > - pr_info("powernv: idle: Saving PACA pointers of all CPUs in their thread sibling PACA\n"); > - for_each_possible_cpu(cpu) { > - int base_cpu = cpu_first_thread_sibling(cpu); > - int idx = cpu_thread_in_core(cpu); > - int i; > - You could move the thread_sibling_pacas allocation to here? Speaking of which... core_idle_state and thread_sibling_pacas are allocated with kmalloc_node... What happens if we take an SLB miss in the idle wakeup code on these guys? Nothing good I think. Perhaps we should put them into the pacas or somewhere in bolted memory. Good cleanup though. Reviewed-by: Nicholas Piggin