From 51888ca25a03125e742ef84d4ddfd74e139707a0 Mon Sep 17 00:00:00 2001 From: Srivatsa Vaddagiri Date: Tue, 27 Jun 2006 02:54:38 -0700 Subject: [PATCH] sched_domain: handle kmalloc failure Try to handle mem allocation failures in build_sched_domains by bailing out and cleaning up thus-far allocated memory. The patch has a direct consequence that we disable load balancing completely (even at sibling level) upon *any* memory allocation failure. [Lee.Schermerhorn@hp.com: bugfix] Signed-off-by: Srivatsa Vaddagir Cc: Nick Piggin Cc: Ingo Molnar Cc: "Siddha, Suresh B" Signed-off-by: Lee Schermerhorn Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/sched.c | 139 ++++++++++++++++++++++++++++++++------------------------- 1 file changed, 78 insertions(+), 61 deletions(-) (limited to 'kernel/sched.c') diff --git a/kernel/sched.c b/kernel/sched.c index 0ec84f57695d..77a2ec55ef7d 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -5820,11 +5820,56 @@ next_sg: } #endif +/* Free memory allocated for various sched_group structures */ +static void free_sched_groups(const cpumask_t *cpu_map) +{ +#ifdef CONFIG_NUMA + int i; + int cpu; + + 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 (sched_group_allnodes) { + kfree(sched_group_allnodes); + sched_group_allnodes_bycpu[cpu] = NULL; + } + + if (!sched_group_nodes) + continue; + + 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; + } + kfree(sched_group_nodes); + sched_group_nodes_bycpu[cpu] = NULL; + } +#endif +} + /* * Build sched domains for a given set of cpus and attach the sched domains * to the individual cpus */ -void build_sched_domains(const cpumask_t *cpu_map) +static int build_sched_domains(const cpumask_t *cpu_map) { int i; #ifdef CONFIG_NUMA @@ -5834,11 +5879,11 @@ void build_sched_domains(const cpumask_t *cpu_map) /* * Allocate the per-node list of sched groups */ - sched_group_nodes = kmalloc(sizeof(struct sched_group*)*MAX_NUMNODES, + sched_group_nodes = kzalloc(sizeof(struct sched_group*)*MAX_NUMNODES, GFP_ATOMIC); if (!sched_group_nodes) { printk(KERN_WARNING "Can not alloc sched group node list\n"); - return; + return -ENOMEM; } sched_group_nodes_bycpu[first_cpu(*cpu_map)] = sched_group_nodes; #endif @@ -5864,7 +5909,7 @@ void build_sched_domains(const cpumask_t *cpu_map) if (!sched_group_allnodes) { printk(KERN_WARNING "Can not alloc allnodes sched group\n"); - break; + goto error; } sched_group_allnodes_bycpu[i] = sched_group_allnodes; @@ -5978,23 +6023,20 @@ void build_sched_domains(const cpumask_t *cpu_map) cpus_and(domainspan, domainspan, *cpu_map); sg = kmalloc(sizeof(struct sched_group), GFP_KERNEL); + if (!sg) { + printk(KERN_WARNING "Can not alloc domain group for " + "node %d\n", i); + goto error; + } sched_group_nodes[i] = sg; for_each_cpu_mask(j, nodemask) { struct sched_domain *sd; sd = &per_cpu(node_domains, j); sd->groups = sg; - if (sd->groups == NULL) { - /* Turn off balancing if we have no groups */ - sd->flags = 0; - } - } - if (!sg) { - printk(KERN_WARNING - "Can not alloc domain group for node %d\n", i); - continue; } sg->cpu_power = 0; sg->cpumask = nodemask; + sg->next = sg; cpus_or(covered, covered, nodemask); prev = sg; @@ -6017,15 +6059,15 @@ void build_sched_domains(const cpumask_t *cpu_map) if (!sg) { printk(KERN_WARNING "Can not alloc domain group for node %d\n", j); - break; + goto error; } sg->cpu_power = 0; sg->cpumask = tmp; + sg->next = prev->next; cpus_or(covered, covered, tmp); prev->next = sg; prev = sg; } - prev->next = sched_group_nodes[i]; } #endif @@ -6088,13 +6130,22 @@ void build_sched_domains(const cpumask_t *cpu_map) * Tune cache-hot values: */ calibrate_migration_costs(cpu_map); + + return 0; + +#ifdef CONFIG_NUMA +error: + free_sched_groups(cpu_map); + return -ENOMEM; +#endif } /* * Set up scheduler domains and groups. Callers must hold the hotplug lock. */ -static void arch_init_sched_domains(const cpumask_t *cpu_map) +static int arch_init_sched_domains(const cpumask_t *cpu_map) { cpumask_t cpu_default_map; + int err; /* * Setup mask for cpus without special case scheduling requirements. @@ -6103,51 +6154,14 @@ static void arch_init_sched_domains(const cpumask_t *cpu_map) */ cpus_andnot(cpu_default_map, *cpu_map, cpu_isolated_map); - build_sched_domains(&cpu_default_map); + err = build_sched_domains(&cpu_default_map); + + return err; } static void arch_destroy_sched_domains(const cpumask_t *cpu_map) { -#ifdef CONFIG_NUMA - int i; - int cpu; - - 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 (sched_group_allnodes) { - kfree(sched_group_allnodes); - sched_group_allnodes_bycpu[cpu] = NULL; - } - - if (!sched_group_nodes) - continue; - - 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; - } - kfree(sched_group_nodes); - sched_group_nodes_bycpu[cpu] = NULL; - } -#endif + free_sched_groups(cpu_map); } /* @@ -6172,9 +6186,10 @@ static void detach_destroy_domains(const cpumask_t *cpu_map) * correct sched domains * Call with hotplug lock held */ -void partition_sched_domains(cpumask_t *partition1, cpumask_t *partition2) +int partition_sched_domains(cpumask_t *partition1, cpumask_t *partition2) { cpumask_t change_map; + int err = 0; cpus_and(*partition1, *partition1, cpu_online_map); cpus_and(*partition2, *partition2, cpu_online_map); @@ -6183,9 +6198,11 @@ void partition_sched_domains(cpumask_t *partition1, cpumask_t *partition2) /* Detach sched domains from all of the affected cpus */ detach_destroy_domains(&change_map); if (!cpus_empty(*partition1)) - build_sched_domains(partition1); - if (!cpus_empty(*partition2)) - build_sched_domains(partition2); + err = build_sched_domains(partition1); + if (!err && !cpus_empty(*partition2)) + err = build_sched_domains(partition2); + + return err; } #ifdef CONFIG_HOTPLUG_CPU -- cgit v1.2.3