From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757262AbZIRRaJ (ORCPT ); Fri, 18 Sep 2009 13:30:09 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756039AbZIRRaI (ORCPT ); Fri, 18 Sep 2009 13:30:08 -0400 Received: from 74-93-104-97-Washington.hfc.comcastbusiness.net ([74.93.104.97]:58722 "EHLO sunset.davemloft.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755344AbZIRRaH (ORCPT ); Fri, 18 Sep 2009 13:30:07 -0400 Date: Fri, 18 Sep 2009 10:30:25 -0700 (PDT) Message-Id: <20090918.103025.100709991.davem@davemloft.net> To: tj@kernel.org Cc: linux-kernel@vger.kernel.org Subject: Re: sparc64 pcpu failures... From: David Miller In-Reply-To: <4AB34722.7050105@kernel.org> References: <20090917.221807.208354411.davem@davemloft.net> <20090917.223723.07032792.davem@davemloft.net> <4AB34722.7050105@kernel.org> X-Mailer: Mew version 6.2.51 on Emacs 22.1 / Mule 5.0 (SAKAKI) 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 From: Tejun Heo Date: Fri, 18 Sep 2009 17:38:58 +0900 > Yes, this would be the result of the new congruent sparse allocator. > Heh... I didn't really expect that WARN_ON() to actually trigger. > What it means is that the farthest percpu units were too far to fit > into vmalloc area so percpu chunks couldn't be allocated in the > vmalloc area. Checking... vmalloc area on sparc64 is only 4G so yeap > that is entirely possible. > > Hmmm... the congruent sparse allocator assumes vmalloc area to be > larger with some margin than the farthest physical memory nodes. On > x86, powerpc and ia64, this holds with sufficient margin. Would it be > possible to modify sparc64 memory layout so that the assumption can be > satisfied? If that's not possible, going back to lpage is an option > but in many ways congruent sparse allocator is better. I'll think about this, thanks.