From mboxrd@z Thu Jan 1 00:00:00 1970 From: Arnd Bergmann Subject: [PATCH] powerpc: mem_init crash for sparsemem Date: Fri, 4 Nov 2005 16:31:16 +0100 MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200511041631.17237.arnd@arndb.de> Sender: owner-linux-mm@kvack.org Return-Path: To: linuxppc64-dev@ozlabs.org Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org List-ID: I have a Cell blade with some broken memory in the middle of the physical address space and this is correctly detected by the firmware, but not relocated. When I enable CONFIG_SPARSEMEM, the memsections for the nonexistant address space do not get struct page entries allocated, as expected. However, mem_init for the non-NUMA configuration tries to access these pages without first looking if they are there. I'm currently using the hack below to work around that, but I have the feeling that there should be a cleaner solution for this. Please comment. Signed-off-by: Arnd Bergmann --- linux-2.6.15-rc.orig/arch/powerpc/mm/mem.c +++ linux-2.6.15-rc/arch/powerpc/mm/mem.c @@ -348,6 +348,9 @@ void __init mem_init(void) #endif for_each_pgdat(pgdat) { for (i = 0; i < pgdat->node_spanned_pages; i++) { + if (!section_has_mem_map(__pfn_to_section + (pgdat->node_start_pfn + i))) + continue; page = pgdat_page_nr(pgdat, i); if (PageReserved(page)) reservedpages++; -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org