From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753883Ab1CKJbh (ORCPT ); Fri, 11 Mar 2011 04:31:37 -0500 Received: from mail-fx0-f46.google.com ([209.85.161.46]:37423 "EHLO mail-fx0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753145Ab1CKJbb (ORCPT ); Fri, 11 Mar 2011 04:31:31 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=sender:date:from:to:cc:subject:message-id:references:mime-version :content-type:content-disposition:in-reply-to:user-agent; b=oNi1UXammixqU69l1G3pl3JqSo4XOkt/FnPF012MM+VFXevID2vOmuia3qUp28Ih80 KIksNrU/46kTYzROonBU4pce/dlF3R0UwT1bKIJWEeoRR2y+eya453RrOr2RgzhwWPM7 s7tfFlBM0wLdO/o2ijy7Mip5k/ESriMfvh4e4= Date: Fri, 11 Mar 2011 10:31:24 +0100 From: Tejun Heo To: Yinghai Lu Cc: David Rientjes , Ingo Molnar , tglx@linutronix.de, "H. Peter Anvin" , linux-kernel@vger.kernel.org Subject: [PATCH x86/mm] x86-64, NUMA: Don't call numa_set_distanc() for all possible node combinations during emulation Message-ID: <20110311093124.GE13038@htj.dyndns.org> References: <4D6E91EC.6040906@kernel.org> <20110302190208.GD28266@mtj.dyndns.org> <4D6E9541.2040201@kernel.org> <20110302191338.GE28266@mtj.dyndns.org> <4D6EA975.8070200@kernel.org> <20110302205704.GF28266@mtj.dyndns.org> <4D6EB335.8000306@kernel.org> <20110303061711.GG28266@mtj.dyndns.org> <4D791C9F.1010500@kernel.org> <20110311082938.GC13038@htj.dyndns.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20110311082938.GC13038@htj.dyndns.org> User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The distance transforming in numa_emulation() used to call numa_set_distance() for all MAX_NUMNODES * MAX_NUMNODES node combinations regardless of which are enabled. As numa_set_distance() ignores all out-of-bound distance settings, this doesn't cause any problem other than looping unnecessarily many times during boot. However, as MAX_NUMNODES * MAX_NUMNODES can be pretty high, update the code such that it iterates through only the enabled combinations. Yinghai Lu identified the issue and provided an initial patch to address the issue; however, the patch was incorrect in that it didn't build emulated distance table when there's no physical distance table and unnecessarily complex. http://thread.gmane.org/gmane.linux.kernel/1107986/focus=1107988 Signed-off-by: Tejun Heo Reported-by: Yinghai Lu --- arch/x86/mm/numa_emulation.c | 23 ++++++++++++----------- 1 file changed, 12 insertions(+), 11 deletions(-) diff --git a/arch/x86/mm/numa_emulation.c b/arch/x86/mm/numa_emulation.c index 3696be0..ad091e4 100644 --- a/arch/x86/mm/numa_emulation.c +++ b/arch/x86/mm/numa_emulation.c @@ -301,7 +301,7 @@ void __init numa_emulation(struct numa_meminfo *numa_meminfo, int numa_dist_cnt) const u64 max_addr = max_pfn << PAGE_SHIFT; u8 *phys_dist = NULL; size_t phys_size = numa_dist_cnt * numa_dist_cnt * sizeof(phys_dist[0]); - int dfl_phys_nid; + int max_emu_nid, dfl_phys_nid; int i, j, ret; if (!emu_cmdline) @@ -358,12 +358,17 @@ void __init numa_emulation(struct numa_meminfo *numa_meminfo, int numa_dist_cnt) node_distance(i, j); } - /* determine the default phys nid to use for unmapped nodes */ + /* + * Determine the max emulated nid and the default phys nid to use + * for unmapped nodes. + */ + max_emu_nid = 0; dfl_phys_nid = NUMA_NO_NODE; for (i = 0; i < ARRAY_SIZE(emu_nid_to_phys); i++) { if (emu_nid_to_phys[i] != NUMA_NO_NODE) { - dfl_phys_nid = emu_nid_to_phys[i]; - break; + max_emu_nid = i; + if (dfl_phys_nid == NUMA_NO_NODE) + dfl_phys_nid = emu_nid_to_phys[i]; } } if (dfl_phys_nid == NUMA_NO_NODE) { @@ -393,14 +398,10 @@ void __init numa_emulation(struct numa_meminfo *numa_meminfo, int numa_dist_cnt) if (emu_nid_to_phys[i] == NUMA_NO_NODE) emu_nid_to_phys[i] = dfl_phys_nid; - /* - * Transform distance table. numa_set_distance() ignores all - * out-of-bound distances. Just call it for every possible node - * combination. - */ + /* transform distance table */ numa_reset_distance(); - for (i = 0; i < MAX_NUMNODES; i++) { - for (j = 0; j < MAX_NUMNODES; j++) { + for (i = 0; i < max_emu_nid + 1; i++) { + for (j = 0; j < max_emu_nid + 1; j++) { int physi = emu_nid_to_phys[i]; int physj = emu_nid_to_phys[j]; int dist;