From 903675569e278af86aa08c2af238b0ab997065d1 Mon Sep 17 00:00:00 2001 From: Andreas Herrmann Date: Wed, 7 Nov 2007 02:12:58 +0100 Subject: x86: fix cpu-hotplug regression Commit d435d862baca3e25e5eec236762a43251b1e7ffc ("cpu hotplug: mce: fix cpu hotplug error handling") changed the error handling in mce_cpu_callback. In cases where not all CPUs are brought up during boot (e.g. using maxcpus and additional_cpus parameters) mce_cpu_callback now returns NOTFIY_BAD because for such CPUs cpu_data is not completely filled when the notifier is called. Thus mce_create_device fails right at its beginning: if (!mce_available(&cpu_data[cpu])) return -EIO; As a quick fix I suggest to check boot_cpu_data for MCE. To reproduce this regression: (1) boot with maxcpus=2 addtional_cpus=2 on a 4 CPU x86-64 system (2) # echo 1 >/sys/devices/system/cpu/cpu2/online -bash: echo: write error: Invalid argument dmesg shows: _cpu_up: attempt to bring up CPU 2 failed Signed-off-by: Andreas Herrmann Signed-off-by: Thomas Gleixner --- arch/x86/kernel/cpu/mcheck/mce_64.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch/x86/kernel/cpu') diff --git a/arch/x86/kernel/cpu/mcheck/mce_64.c b/arch/x86/kernel/cpu/mcheck/mce_64.c index 447b351f1f2..4b21d29fb5a 100644 --- a/arch/x86/kernel/cpu/mcheck/mce_64.c +++ b/arch/x86/kernel/cpu/mcheck/mce_64.c @@ -810,7 +810,7 @@ static __cpuinit int mce_create_device(unsigned int cpu) int err; int i; - if (!mce_available(&cpu_data(cpu))) + if (!mce_available(&boot_cpu_data)) return -EIO; memset(&per_cpu(device_mce, cpu).kobj, 0, sizeof(struct kobject)); -- cgit v1.2.3 From c0c52d28e05e8bdaa2126570c02ecb1a7358cecc Mon Sep 17 00:00:00 2001 From: Andreas Herrmann Date: Thu, 1 Nov 2007 19:32:17 +0100 Subject: x86: show cpuinfo only for online CPUs Fix regressions introduced with 92cb7612aee39642d109b8d935ad265e602c0563. It can happen that cpuinfo is displayed for CPUs that are not online or even worse for CPUs not present at all. As an example, following was shown for a "second" CPU of a single core K8 variant: processor : 0 vendor_id : unknown cpu family : 0 model : 0 model name : unknown stepping : 0 cache size : 0 KB fpu : yes fpu_exception : yes cpuid level : 0 wp : yes flags : bogomips : 0.00 clflush size : 0 cache_alignment : 0 address sizes : 0 bits physical, 0 bits virtual power management: Signed-off-by: Andreas Herrmann Signed-off-by: Thomas Gleixner --- arch/x86/kernel/cpu/proc.c | 8 +++----- 1 file changed, 3 insertions(+), 5 deletions(-) (limited to 'arch/x86/kernel/cpu') diff --git a/arch/x86/kernel/cpu/proc.c b/arch/x86/kernel/cpu/proc.c index 066f8c6af4d..3900e46d66d 100644 --- a/arch/x86/kernel/cpu/proc.c +++ b/arch/x86/kernel/cpu/proc.c @@ -89,8 +89,6 @@ static int show_cpuinfo(struct seq_file *m, void *v) int fpu_exception; #ifdef CONFIG_SMP - if (!cpu_online(n)) - return 0; n = c->cpu_index; #endif seq_printf(m, "processor\t: %d\n" @@ -177,14 +175,14 @@ static int show_cpuinfo(struct seq_file *m, void *v) static void *c_start(struct seq_file *m, loff_t *pos) { if (*pos == 0) /* just in case, cpu 0 is not the first */ - *pos = first_cpu(cpu_possible_map); - if ((*pos) < NR_CPUS && cpu_possible(*pos)) + *pos = first_cpu(cpu_online_map); + if ((*pos) < NR_CPUS && cpu_online(*pos)) return &cpu_data(*pos); return NULL; } static void *c_next(struct seq_file *m, void *v, loff_t *pos) { - *pos = next_cpu(*pos, cpu_possible_map); + *pos = next_cpu(*pos, cpu_online_map); return c_start(m, pos); } static void c_stop(struct seq_file *m, void *v) -- cgit v1.2.3