From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tejun Heo Date: Wed, 19 Aug 2009 14:36:21 +0000 Subject: Re: [RFC PATCH] ia64: convert to dynamic percpu allocator Message-Id: <4A8C0DE5.302@kernel.org> List-Id: References: <4A65B0AB.5000608@kernel.org> <4A663DC7.4060600@kernel.org> <4A695897.2020902@kernel.org> <4A826785.4000509@kernel.org> In-Reply-To: <4A826785.4000509@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: "Yu, Fenghua" Cc: "Luck, Tony" , 'lkml' , "'linux-arch@vger.kernel.org'" , "'linux-ia64@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