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| author | travis@sgi.com <travis@sgi.com> | 2008-01-30 13:33:22 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2008-01-30 13:33:22 +0100 |
| commit | c49a4955ea504c82f6b690491639bba5b8c1dc47 (patch) | |
| tree | badef899e3e3376c1af68b942b7f6c8ff9a36df5 | |
| parent | x86: change bios_cpu_apicid to percpu data variable fixup (diff) | |
| download | linux-c49a4955ea504c82f6b690491639bba5b8c1dc47.tar.xz linux-c49a4955ea504c82f6b690491639bba5b8c1dc47.zip | |
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.debug | 12 | ||||
| -rw-r--r-- | arch/x86/mm/numa_64.c | 3 | ||||
| -rw-r--r-- | include/asm-x86/topology.h | 7 |
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 This results in a large slowdown, but helps to find certain types of memory corruptions. +config DEBUG_PER_CPU_MAPS + bool "Debug access to per_cpu maps" + depends on DEBUG_KERNEL + depends on X86_64_SMP + default n + help + Say Y to verify that the per_cpu map being accessed has + been setup. Adds a fair amount of code to kernel memory + and decreases performance. + + Say N if unsure. + config DEBUG_RODATA bool "Write protect kernel read-only data structures" 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] = { void *x86_cpu_to_node_map_early_ptr; DEFINE_PER_CPU(u16, x86_cpu_to_node_map) = NUMA_NO_NODE; EXPORT_PER_CPU_SYMBOL(x86_cpu_to_node_map); +#ifdef CONFIG_DEBUG_PER_CPU_MAPS +EXPORT_SYMBOL(x86_cpu_to_node_map_early_ptr); +#endif u16 apicid_to_node[MAX_LOCAL_APIC] __cpuinitdata = { [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) static inline int cpu_to_node(int cpu) { +#ifdef CONFIG_DEBUG_PER_CPU_MAPS + if(x86_cpu_to_node_map_early_ptr) { + printk("KERN_NOTICE cpu_to_node(%d): usage too early!\n", + (int)cpu); + BUG(); + } +#endif if(per_cpu_offset(cpu)) return per_cpu(x86_cpu_to_node_map, cpu); else |