From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tejun Heo Subject: Re: [RFC PATCH] ia64: convert to dynamic percpu allocator Date: Wed, 19 Aug 2009 23:36:21 +0900 Message-ID: <4A8C0DE5.302@kernel.org> References: <4A65B0AB.5000608@kernel.org> <4A663DC7.4060600@kernel.org> <4A695897.2020902@kernel.org> <4A826785.4000509@kernel.org> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <4A826785.4000509@kernel.org> Sender: linux-ia64-owner@vger.kernel.org To: "Yu, Fenghua" Cc: "Luck, Tony" , 'lkml' , "'linux-arch@vger.kernel.org'" , "'linux-ia64@vger.kernel.org'" List-Id: linux-arch.vger.kernel.org Tejun Heo wrote: > * Is ai->reserved_size necessary for ia64? This is necessary if > there's linking range restriction when loading modules. > ai->reserved_size guarantees that all static module percpu variables > are allocated in the first chunk which will be in the linear address > range and very close to __per_cpu_start. If ai->reserved_size is > not set, these areas are likely to end up high in the vmalloc area. > > For example, x86_64 assumes 32bit relocations should be enough to > link module symbols and thus needs to set reserved_size but x86_32 > can link to the whole 32bit space and thus can leave reserved_size > at zero. > > * After determining the above, we can set ai->dyn_size to be > > ai->dyn_size = min(ai->unit_size - ai->static_size - ai->reserved_size, > PERCPU_DYNAMIC_RESERVE); > > Would the above work? > >> Even with the above PAGE_SIZE changes, the kernel still reports >> warning from 952: WARN_ON(chunk->immutable) and then panic. > > Hah... strange. Can you please attach full boot log? This is > dicontig configuration, right? Any news? Thanks. -- tejun From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from hera.kernel.org ([140.211.167.34]:50750 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752343AbZHSOgg (ORCPT ); Wed, 19 Aug 2009 10:36:36 -0400 Message-ID: <4A8C0DE5.302@kernel.org> Date: Wed, 19 Aug 2009 23:36:21 +0900 From: Tejun Heo MIME-Version: 1.0 Subject: Re: [RFC PATCH] ia64: convert to dynamic percpu allocator References: <4A65B0AB.5000608@kernel.org> <4A663DC7.4060600@kernel.org> <4A695897.2020902@kernel.org> <4A826785.4000509@kernel.org> In-Reply-To: <4A826785.4000509@kernel.org> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-arch-owner@vger.kernel.org List-ID: To: "Yu, Fenghua" Cc: "Luck, Tony" , 'lkml' , "'linux-arch@vger.kernel.org'" , "'linux-ia64@vger.kernel.org'" Message-ID: <20090819143621.7khJ_8C2I1m4eZ8S8E67VkPWC4b1P8p6jL8nAREPxDw@z> Tejun Heo wrote: > * Is ai->reserved_size necessary for ia64? This is necessary if > there's linking range restriction when loading modules. > ai->reserved_size guarantees that all static module percpu variables > are allocated in the first chunk which will be in the linear address > range and very close to __per_cpu_start. If ai->reserved_size is > not set, these areas are likely to end up high in the vmalloc area. > > For example, x86_64 assumes 32bit relocations should be enough to > link module symbols and thus needs to set reserved_size but x86_32 > can link to the whole 32bit space and thus can leave reserved_size > at zero. > > * After determining the above, we can set ai->dyn_size to be > > ai->dyn_size = min(ai->unit_size - ai->static_size - ai->reserved_size, > PERCPU_DYNAMIC_RESERVE); > > Would the above work? > >> Even with the above PAGE_SIZE changes, the kernel still reports >> warning from 952: WARN_ON(chunk->immutable) and then panic. > > Hah... strange. Can you please attach full boot log? This is > dicontig configuration, right? Any news? Thanks. -- tejun