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authortravis@sgi.com <travis@sgi.com>2008-01-30 07:33:22 -0500
committerIngo Molnar <mingo@elte.hu>2008-01-30 07:33:22 -0500
commitc49a4955ea504c82f6b690491639bba5b8c1dc47 (patch)
treebadef899e3e3376c1af68b942b7f6c8ff9a36df5
parent602a54a8cab2759fceb20b3e0c2a27c4eac005df (diff)
x86: add debug of invalid per_cpu map accesses
Provide a means to trap usages of per_cpu map variables before they are setup. Define CONFIG_DEBUG_PER_CPU_MAPS to activate. Signed-off-by: Mike Travis <travis@sgi.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
-rw-r--r--arch/x86/Kconfig.debug12
-rw-r--r--arch/x86/mm/numa_64.c3
-rw-r--r--include/asm-x86/topology.h7
3 files changed, 22 insertions, 0 deletions
diff --git a/arch/x86/Kconfig.debug b/arch/x86/Kconfig.debug
index 88420af98140..0a82b889d76e 100644
--- a/arch/x86/Kconfig.debug
+++ b/arch/x86/Kconfig.debug
@@ -47,6 +47,18 @@ config DEBUG_PAGEALLOC
47 This results in a large slowdown, but helps to find certain types 47 This results in a large slowdown, but helps to find certain types
48 of memory corruptions. 48 of memory corruptions.
49 49
50config DEBUG_PER_CPU_MAPS
51 bool "Debug access to per_cpu maps"
52 depends on DEBUG_KERNEL
53 depends on X86_64_SMP
54 default n
55 help
56 Say Y to verify that the per_cpu map being accessed has
57 been setup. Adds a fair amount of code to kernel memory
58 and decreases performance.
59
60 Say N if unsure.
61
50config DEBUG_RODATA 62config DEBUG_RODATA
51 bool "Write protect kernel read-only data structures" 63 bool "Write protect kernel read-only data structures"
52 depends on DEBUG_KERNEL 64 depends on DEBUG_KERNEL
diff --git a/arch/x86/mm/numa_64.c b/arch/x86/mm/numa_64.c
index 5d24dc1ec237..e157cb274b25 100644
--- a/arch/x86/mm/numa_64.c
+++ b/arch/x86/mm/numa_64.c
@@ -37,6 +37,9 @@ u16 x86_cpu_to_node_map_init[NR_CPUS] = {
37void *x86_cpu_to_node_map_early_ptr; 37void *x86_cpu_to_node_map_early_ptr;
38DEFINE_PER_CPU(u16, x86_cpu_to_node_map) = NUMA_NO_NODE; 38DEFINE_PER_CPU(u16, x86_cpu_to_node_map) = NUMA_NO_NODE;
39EXPORT_PER_CPU_SYMBOL(x86_cpu_to_node_map); 39EXPORT_PER_CPU_SYMBOL(x86_cpu_to_node_map);
40#ifdef CONFIG_DEBUG_PER_CPU_MAPS
41EXPORT_SYMBOL(x86_cpu_to_node_map_early_ptr);
42#endif
40 43
41u16 apicid_to_node[MAX_LOCAL_APIC] __cpuinitdata = { 44u16 apicid_to_node[MAX_LOCAL_APIC] __cpuinitdata = {
42 [0 ... MAX_LOCAL_APIC-1] = NUMA_NO_NODE 45 [0 ... MAX_LOCAL_APIC-1] = NUMA_NO_NODE
diff --git a/include/asm-x86/topology.h b/include/asm-x86/topology.h
index 040374f030cf..f1e12329078e 100644
--- a/include/asm-x86/topology.h
+++ b/include/asm-x86/topology.h
@@ -66,6 +66,13 @@ static inline int early_cpu_to_node(int cpu)
66 66
67static inline int cpu_to_node(int cpu) 67static inline int cpu_to_node(int cpu)
68{ 68{
69#ifdef CONFIG_DEBUG_PER_CPU_MAPS
70 if(x86_cpu_to_node_map_early_ptr) {
71 printk("KERN_NOTICE cpu_to_node(%d): usage too early!\n",
72 (int)cpu);
73 BUG();
74 }
75#endif
69 if(per_cpu_offset(cpu)) 76 if(per_cpu_offset(cpu))
70 return per_cpu(x86_cpu_to_node_map, cpu); 77 return per_cpu(x86_cpu_to_node_map, cpu);
71 else 78 else