From: Dimitri Sivanich <sivanich@sgi.com>
Here's a version of the isolated scheduler domain code that I mentioned in
an RFC on 7/22. This patch applies on top of 2.6.8-rc2-mm1 (to include all
of the new arch_init_sched_domain code). This patch also contains the 2
line fix to remove the check of first_cpu(sd->groups->cpumask)) that Jesse
sent in earlier.
Note that this has not been tested with CONFIG_SCHED_SMT. I hope that my
handling of those instances is OK.
Signed-off-by: Dimitri Sivanich <sivanich@sgi.com>
DESC
sched-isolated-sched-domains-fix
EDESC
Signed-off-by: Andrew Morton <akpm@osdl.org>
---
25-akpm/kernel/sched.c | 81 +++++++++++++++++++++++++++++++++++++++++++++----
1 files changed, 76 insertions(+), 5 deletions(-)
diff -puN kernel/sched.c~sched-isolated-sched-domains kernel/sched.c
--- 25/kernel/sched.c~sched-isolated-sched-domains Mon Aug 16 16:03:15 2004
+++ 25-akpm/kernel/sched.c Mon Aug 16 16:03:19 2004
@@ -3710,6 +3710,31 @@ __init static int cpu_to_node_group(int
}
#endif
+/* Groups for isolated scheduling domains */
+static struct sched_group sched_group_isolated[NR_CPUS];
+__init static int cpu_to_isolated_group(int cpu)
+{
+ return cpu;
+}
+
+cpumask_t __initdata cpu_isolated_map = CPU_MASK_NONE; /* cpus with isolated domains */
+
+/* Setup the mask of cpus configured for isolated domains */
+static int __init
+isolated_cpu_setup(char *str)
+{
+ int ints[NR_CPUS], i;
+
+ str = get_options(str, ARRAY_SIZE(ints), ints);
+ cpus_clear(cpu_isolated_map);
+ for (i=1; i<=ints[0]; i++) {
+ cpu_set(ints[i], cpu_isolated_map);
+ }
+ return 1;
+}
+
+__setup ("isolcpus=", isolated_cpu_setup);
+
/*
* init_sched_build_groups takes an array of groups, the cpumask we wish
* to span, and a pointer to a function which identifies what group a CPU
@@ -3758,6 +3783,15 @@ __init static void init_sched_build_grou
__init static void arch_init_sched_domains(void)
{
int i;
+ cpumask_t cpu_default_map;
+
+ /*
+ * Setup mask for cpus without special case scheduling requirements.
+ * For now this just excludes isolated cpus, but could be used to
+ * exclude other special cases in the future.
+ */
+ cpus_complement(cpu_default_map, cpu_isolated_map);
+ cpus_and(cpu_default_map, cpu_default_map, cpu_possible_map);
/* Set up domains */
for_each_cpu(i) {
@@ -3765,12 +3799,37 @@ __init static void arch_init_sched_domai
struct sched_domain *sd = NULL, *p;
cpumask_t nodemask = node_to_cpumask(cpu_to_node(i));
+ cpus_and(nodemask, nodemask, cpu_default_map);
+
+ /*
+ * Set up isolated domains.
+ * Unlike those of other cpus, the domains and groups are
+ * single level, and span a single cpu.
+ */
+ if (cpu_isset(i, cpu_isolated_map)) {
+#ifdef CONFIG_SCHED_SMT
+ sd = &per_cpu(cpu_domains, i);
+#else
+ sd = &per_cpu(phys_domains, i);
+#endif
+ group = cpu_to_isolated_group(i);
+ *sd = SD_CPU_INIT;
+ cpu_set(i, sd->span);
+ sd->balance_interval = INT_MAX; /* Don't balance */
+ sd->flags = 0; /* Avoid WAKE_ */
+ sd->groups = &sched_group_isolated[group];
+ printk(KERN_INFO "Setting up cpu %d isolated.\n", i);
+ /* Single level, so continue with next cpu */
+ continue;
+ }
+
#ifdef CONFIG_NUMA
sd = &per_cpu(node_domains, i);
group = cpu_to_node_group(i);
*sd = SD_NODE_INIT;
/* FIXME: should be multilevel, in arch code */
sd->span = sched_domain_node_span(i, SD_NODES_PER_DOMAIN);
+ cpus_and(sd->span, sd->span, cpu_default_map);
sd->groups = &sched_group_nodes[group];
#endif
@@ -3788,6 +3847,7 @@ __init static void arch_init_sched_domai
group = cpu_to_cpu_group(i);
*sd = SD_SIBLING_INIT;
sd->span = cpu_sibling_map[i];
+ cpus_and(sd->span, sd->span, cpu_default_map);
sd->parent = p;
sd->groups = &sched_group_cpus[group];
#endif
@@ -3796,19 +3856,30 @@ __init static void arch_init_sched_domai
#ifdef CONFIG_SCHED_SMT
/* Set up CPU (sibling) groups */
for_each_cpu(i) {
- if (i != first_cpu(cpu_sibling_map[i]))
+ cpumask_t this_sibling_map = cpu_sibling_map[i];
+ cpus_and(this_sibling_map, this_sibling_map, cpu_default_map);
+ if (i != first_cpu(this_sibling_map))
continue;
- init_sched_build_groups(sched_group_cpus, cpu_sibling_map[i],
+ init_sched_build_groups(sched_group_cpus, this_sibling_map,
&cpu_to_cpu_group);
}
#endif
+ /* Set up isolated groups */
+ for_each_cpu_mask(i, cpu_isolated_map) {
+ cpumask_t mask;
+ cpus_clear(mask);
+ cpu_set(i, mask);
+ init_sched_build_groups(sched_group_isolated, mask,
+ &cpu_to_isolated_group);
+ }
+
/* Set up physical groups */
for (i = 0; i < MAX_NUMNODES; i++) {
cpumask_t nodemask = node_to_cpumask(i);
- cpus_and(nodemask, nodemask, cpu_possible_map);
+ cpus_and(nodemask, nodemask, cpu_default_map);
if (cpus_empty(nodemask))
continue;
@@ -3818,12 +3889,12 @@ __init static void arch_init_sched_domai
#ifdef CONFIG_NUMA
/* Set up node groups */
- init_sched_build_groups(sched_group_nodes, cpu_possible_map,
+ init_sched_build_groups(sched_group_nodes, cpu_default_map,
&cpu_to_node_group);
#endif
/* Calculate CPU power for physical packages and nodes */
- for_each_cpu(i) {
+ for_each_cpu_mask(i, cpu_default_map) {
int power;
struct sched_domain *sd;
#ifdef CONFIG_SCHED_SMT
_