From: John Hawkes Date: Tue, 6 Sep 2005 22:18:14 +0000 (-0700) Subject: [PATCH] cpusets: fix the "dynamic sched domains" bug X-Git-Tag: v2.6.14-rc1~637 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=d1b551386a5f3f50a5003b691f819b07f8e6f034;p=linux-2.6 [PATCH] cpusets: fix the "dynamic sched domains" bug For a NUMA system with multiple CPUs per node, declaring a cpu-exclusive cpuset that includes only some, but not all, of the CPUs in a node will mangle the sched domain structures. Signed-off-by: John Hawkes Cc; Ingo Molnar Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- diff --git a/kernel/sched.c b/kernel/sched.c index 50860ad5b6..9508527845 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -4970,10 +4970,10 @@ static int cpu_to_phys_group(int cpu) * gets dynamically allocated. */ static DEFINE_PER_CPU(struct sched_domain, node_domains); -static struct sched_group *sched_group_nodes[MAX_NUMNODES]; +static struct sched_group **sched_group_nodes_bycpu[NR_CPUS]; static DEFINE_PER_CPU(struct sched_domain, allnodes_domains); -static struct sched_group sched_group_allnodes[MAX_NUMNODES]; +static struct sched_group *sched_group_allnodes_bycpu[NR_CPUS]; static int cpu_to_allnodes_group(int cpu) { @@ -4988,6 +4988,21 @@ static int cpu_to_allnodes_group(int cpu) void build_sched_domains(const cpumask_t *cpu_map) { int i; +#ifdef CONFIG_NUMA + struct sched_group **sched_group_nodes = NULL; + struct sched_group *sched_group_allnodes = NULL; + + /* + * Allocate the per-node list of sched groups + */ + sched_group_nodes = kmalloc(sizeof(struct sched_group*)*MAX_NUMNODES, + GFP_ATOMIC); + if (!sched_group_nodes) { + printk(KERN_WARNING "Can not alloc sched group node list\n"); + return; + } + sched_group_nodes_bycpu[first_cpu(*cpu_map)] = sched_group_nodes; +#endif /* * Set up domains for cpus specified by the cpu_map. @@ -5000,8 +5015,21 @@ void build_sched_domains(const cpumask_t *cpu_map) cpus_and(nodemask, nodemask, *cpu_map); #ifdef CONFIG_NUMA - if (num_online_cpus() + if (cpus_weight(*cpu_map) > SD_NODES_PER_DOMAIN*cpus_weight(nodemask)) { + if (!sched_group_allnodes) { + sched_group_allnodes + = kmalloc(sizeof(struct sched_group) + * MAX_NUMNODES, + GFP_KERNEL); + if (!sched_group_allnodes) { + printk(KERN_WARNING + "Can not alloc allnodes sched group\n"); + break; + } + sched_group_allnodes_bycpu[i] + = sched_group_allnodes; + } sd = &per_cpu(allnodes_domains, i); *sd = SD_ALLNODES_INIT; sd->span = *cpu_map; @@ -5065,8 +5093,9 @@ void build_sched_domains(const cpumask_t *cpu_map) #ifdef CONFIG_NUMA /* Set up node groups */ - init_sched_build_groups(sched_group_allnodes, *cpu_map, - &cpu_to_allnodes_group); + if (sched_group_allnodes) + init_sched_build_groups(sched_group_allnodes, *cpu_map, + &cpu_to_allnodes_group); for (i = 0; i < MAX_NUMNODES; i++) { /* Set up node groups */ @@ -5077,8 +5106,10 @@ void build_sched_domains(const cpumask_t *cpu_map) int j; cpus_and(nodemask, nodemask, *cpu_map); - if (cpus_empty(nodemask)) + if (cpus_empty(nodemask)) { + sched_group_nodes[i] = NULL; continue; + } domainspan = sched_domain_node_span(i); cpus_and(domainspan, domainspan, *cpu_map); @@ -5223,24 +5254,42 @@ static void arch_destroy_sched_domains(const cpumask_t *cpu_map) { #ifdef CONFIG_NUMA int i; - for (i = 0; i < MAX_NUMNODES; i++) { - cpumask_t nodemask = node_to_cpumask(i); - struct sched_group *oldsg, *sg = sched_group_nodes[i]; + int cpu; - cpus_and(nodemask, nodemask, *cpu_map); - if (cpus_empty(nodemask)) - continue; + for_each_cpu_mask(cpu, *cpu_map) { + struct sched_group *sched_group_allnodes + = sched_group_allnodes_bycpu[cpu]; + struct sched_group **sched_group_nodes + = sched_group_nodes_bycpu[cpu]; - if (sg == NULL) + if (sched_group_allnodes) { + kfree(sched_group_allnodes); + sched_group_allnodes_bycpu[cpu] = NULL; + } + + if (!sched_group_nodes) continue; - sg = sg->next; + + for (i = 0; i < MAX_NUMNODES; i++) { + cpumask_t nodemask = node_to_cpumask(i); + struct sched_group *oldsg, *sg = sched_group_nodes[i]; + + cpus_and(nodemask, nodemask, *cpu_map); + if (cpus_empty(nodemask)) + continue; + + if (sg == NULL) + continue; + sg = sg->next; next_sg: - oldsg = sg; - sg = sg->next; - kfree(oldsg); - if (oldsg != sched_group_nodes[i]) - goto next_sg; - sched_group_nodes[i] = NULL; + oldsg = sg; + sg = sg->next; + kfree(oldsg); + if (oldsg != sched_group_nodes[i]) + goto next_sg; + } + kfree(sched_group_nodes); + sched_group_nodes_bycpu[cpu] = NULL; } #endif }