From 369381694ddcf03f1de403501c8b97099b5109ec Mon Sep 17 00:00:00 2001 From: Srivatsa Vaddagiri Date: Tue, 27 Jun 2006 02:54:41 -0700 Subject: [PATCH] [PATCH] sched_domai: Allocate sched_group structures dynamically As explained here: http://marc.theaimsgroup.com/?l=linux-kernel&m=114327539012323&w=2 there is a problem with sharing sched_group structures between two separate sched_group structures for different sched_domains. The patch has been tested and found to avoid the kernel lockup problem described in above URL. Signed-off-by: Srivatsa Vaddagiri Cc: Nick Piggin Cc: Ingo Molnar Cc: "Siddha, Suresh B" Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/sched.c | 48 +++++++++++++++++++++++++++++++++++++++++++----- 1 file changed, 43 insertions(+), 5 deletions(-) diff --git a/kernel/sched.c b/kernel/sched.c index ee4211bd40c5..122b75584a13 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -5747,7 +5747,7 @@ static int cpu_to_cpu_group(int cpu) #ifdef CONFIG_SCHED_MC static DEFINE_PER_CPU(struct sched_domain, core_domains); -static struct sched_group sched_group_core[NR_CPUS]; +static struct sched_group *sched_group_core_bycpu[NR_CPUS]; #endif #if defined(CONFIG_SCHED_MC) && defined(CONFIG_SCHED_SMT) @@ -5763,7 +5763,7 @@ static int cpu_to_core_group(int cpu) #endif static DEFINE_PER_CPU(struct sched_domain, phys_domains); -static struct sched_group sched_group_phys[NR_CPUS]; +static struct sched_group *sched_group_phys_bycpu[NR_CPUS]; static int cpu_to_phys_group(int cpu) { #if defined(CONFIG_SCHED_MC) @@ -5823,9 +5823,9 @@ next_sg: /* Free memory allocated for various sched_group structures */ static void free_sched_groups(const cpumask_t *cpu_map) { + int cpu; #ifdef CONFIG_NUMA int i; - int cpu; for_each_cpu_mask(cpu, *cpu_map) { struct sched_group *sched_group_allnodes @@ -5863,6 +5863,18 @@ next_sg: sched_group_nodes_bycpu[cpu] = NULL; } #endif + for_each_cpu_mask(cpu, *cpu_map) { + if (sched_group_phys_bycpu[cpu]) { + kfree(sched_group_phys_bycpu[cpu]); + sched_group_phys_bycpu[cpu] = NULL; + } +#ifdef CONFIG_SCHED_MC + if (sched_group_core_bycpu[cpu]) { + kfree(sched_group_core_bycpu[cpu]); + sched_group_core_bycpu[cpu] = NULL; + } +#endif + } } /* @@ -5872,6 +5884,10 @@ next_sg: static int build_sched_domains(const cpumask_t *cpu_map) { int i; + struct sched_group *sched_group_phys = NULL; +#ifdef CONFIG_SCHED_MC + struct sched_group *sched_group_core = NULL; +#endif #ifdef CONFIG_NUMA struct sched_group **sched_group_nodes = NULL; struct sched_group *sched_group_allnodes = NULL; @@ -5930,6 +5946,18 @@ static int build_sched_domains(const cpumask_t *cpu_map) cpus_and(sd->span, sd->span, *cpu_map); #endif + if (!sched_group_phys) { + sched_group_phys + = kmalloc(sizeof(struct sched_group) * NR_CPUS, + GFP_KERNEL); + if (!sched_group_phys) { + printk (KERN_WARNING "Can not alloc phys sched" + "group\n"); + goto error; + } + sched_group_phys_bycpu[i] = sched_group_phys; + } + p = sd; sd = &per_cpu(phys_domains, i); group = cpu_to_phys_group(i); @@ -5939,6 +5967,18 @@ static int build_sched_domains(const cpumask_t *cpu_map) sd->groups = &sched_group_phys[group]; #ifdef CONFIG_SCHED_MC + if (!sched_group_core) { + sched_group_core + = kmalloc(sizeof(struct sched_group) * NR_CPUS, + GFP_KERNEL); + if (!sched_group_core) { + printk (KERN_WARNING "Can not alloc core sched" + "group\n"); + goto error; + } + sched_group_core_bycpu[i] = sched_group_core; + } + p = sd; sd = &per_cpu(core_domains, i); group = cpu_to_core_group(i); @@ -6134,11 +6174,9 @@ static int build_sched_domains(const cpumask_t *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. -- 2.20.1