From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752959AbZIAH6Y (ORCPT ); Tue, 1 Sep 2009 03:58:24 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752061AbZIAH6X (ORCPT ); Tue, 1 Sep 2009 03:58:23 -0400 Received: from hera.kernel.org ([140.211.167.34]:47438 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751937AbZIAH6X (ORCPT ); Tue, 1 Sep 2009 03:58:23 -0400 Message-ID: <4A9CD41C.8060604@kernel.org> Date: Tue, 01 Sep 2009 16:58:20 +0900 From: Tejun Heo User-Agent: Thunderbird 2.0.0.22 (X11/20090605) MIME-Version: 1.0 To: Meelis Roos CC: David Miller , sparclinux@vger.kernel.org, Linux Kernel list Subject: Re: boot panic after oops from sysfs_new_dirent References: <20090831.142215.111904849.davem@davemloft.net> <4A9CC9E9.2070609@kernel.org> <4A9CCD92.4090909@kernel.org> In-Reply-To: X-Enigmail-Version: 0.95.7 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.0 (hera.kernel.org [127.0.0.1]); Tue, 01 Sep 2009 07:58:23 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Meelis Roos wrote: >> Ummm.... one more question. Is cpu0 missing? Can you please post the >> output of "cat /proc/cpuinfo"? > > Yes, there's no CPU numbered 0, the numbers come from hardware slots on > backplane. Aha... Does the following patch fix the problem? diff --git a/mm/percpu.c b/mm/percpu.c index 5fe3784..3311c89 100644 --- a/mm/percpu.c +++ b/mm/percpu.c @@ -197,7 +197,12 @@ static unsigned long pcpu_chunk_addr(struct pcpu_chunk *chunk, static bool pcpu_chunk_page_occupied(struct pcpu_chunk *chunk, int page_idx) { - return *pcpu_chunk_pagep(chunk, 0, page_idx) != NULL; + /* + * Any possible cpu id can be used here, so there's no need to + * worry about preemption or cpu hotplug. + */ + return *pcpu_chunk_pagep(chunk, raw_smp_processor_id(), + page_idx) != NULL; } /* set the pointer to a chunk in a page struct */ @@ -297,6 +302,14 @@ static struct pcpu_chunk *pcpu_chunk_addr_search(void *addr) return pcpu_first_chunk; } + /* + * The address is relative to unit0 which might be unused and + * thus unmapped. Offset the address to the unit space of the + * current processor before looking it up in the vmalloc + * space. Note that any possible cpu id can be used here, so + * there's no need to worry about preemption or cpu hotplug. + */ + addr += raw_smp_processor_id() * pcpu_unit_size; return pcpu_get_page_chunk(vmalloc_to_page(addr)); } -- tejun