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linux-next/arch/ia64/kernel/numa.c
holt@sgi.com 2c6e6db41f [IA64] Minimize per_cpu reservations.
This attached patch significantly shrinks boot memory allocation on ia64.
It does this by not allocating per_cpu areas for cpus that can never
exist.

In the case where acpi does not have any numa node description of the
cpus, I defaulted to assigning the first 32 round-robin on the known
nodes..  For the !CONFIG_ACPI  I used for_each_possible_cpu().

Signed-off-by: Robin Holt <holt@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
2008-04-08 13:51:35 -07:00

86 lines
2.4 KiB
C

/*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
* ia64 kernel NUMA specific stuff
*
* Copyright (C) 2002 Erich Focht <efocht@ess.nec.de>
* Copyright (C) 2004 Silicon Graphics, Inc.
* Jesse Barnes <jbarnes@sgi.com>
*/
#include <linux/topology.h>
#include <linux/module.h>
#include <asm/processor.h>
#include <asm/smp.h>
u16 cpu_to_node_map[NR_CPUS] __cacheline_aligned;
EXPORT_SYMBOL(cpu_to_node_map);
cpumask_t node_to_cpu_mask[MAX_NUMNODES] __cacheline_aligned;
EXPORT_SYMBOL(node_to_cpu_mask);
void __cpuinit map_cpu_to_node(int cpu, int nid)
{
int oldnid;
if (nid < 0) { /* just initialize by zero */
cpu_to_node_map[cpu] = 0;
return;
}
/* sanity check first */
oldnid = cpu_to_node_map[cpu];
if (cpu_isset(cpu, node_to_cpu_mask[oldnid])) {
return; /* nothing to do */
}
/* we don't have cpu-driven node hot add yet...
In usual case, node is created from SRAT at boot time. */
if (!node_online(nid))
nid = first_online_node;
cpu_to_node_map[cpu] = nid;
cpu_set(cpu, node_to_cpu_mask[nid]);
return;
}
void __cpuinit unmap_cpu_from_node(int cpu, int nid)
{
WARN_ON(!cpu_isset(cpu, node_to_cpu_mask[nid]));
WARN_ON(cpu_to_node_map[cpu] != nid);
cpu_to_node_map[cpu] = 0;
cpu_clear(cpu, node_to_cpu_mask[nid]);
}
/**
* build_cpu_to_node_map - setup cpu to node and node to cpumask arrays
*
* Build cpu to node mapping and initialize the per node cpu masks using
* info from the node_cpuid array handed to us by ACPI.
*/
void __init build_cpu_to_node_map(void)
{
int cpu, i, node;
for(node=0; node < MAX_NUMNODES; node++)
cpus_clear(node_to_cpu_mask[node]);
for_each_possible_early_cpu(cpu) {
node = -1;
for (i = 0; i < NR_CPUS; ++i)
if (cpu_physical_id(cpu) == node_cpuid[i].phys_id) {
node = node_cpuid[i].nid;
break;
}
map_cpu_to_node(cpu, node);
}
}