From fcef8576d8a64fc603e719c97d423f9f6d4e0e8b Mon Sep 17 00:00:00 2001 From: Rusty Russell Date: Fri, 13 Mar 2009 14:49:49 +1030 Subject: [PATCH] cpumask: convert arch/x86/kernel/nmi.c's backtrace_mask to a cpumask_var_t Impact: cleanup, reduce memory usage for CONFIG_CPUMASK_OFFSTACK=y I *think* every path calls check_nmi_watchdog before using the watchdog, so that's the right place for the initialization. If that's wrong, we'll get a nice NULL-deref with CONFIG_CPUMASK_OFFSTACK=y, and have uncovered another bug. Signed-off-by: Rusty Russell --- arch/x86/kernel/apic/nmi.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) diff --git a/arch/x86/kernel/apic/nmi.c b/arch/x86/kernel/apic/nmi.c index bdfad80c3cf1..d6bd62407152 100644 --- a/arch/x86/kernel/apic/nmi.c +++ b/arch/x86/kernel/apic/nmi.c @@ -39,7 +39,7 @@ int unknown_nmi_panic; int nmi_watchdog_enabled; -static cpumask_t backtrace_mask = CPU_MASK_NONE; +static cpumask_var_t backtrace_mask; /* nmi_active: * >0: the lapic NMI watchdog is active, but can be disabled @@ -138,6 +138,7 @@ int __init check_nmi_watchdog(void) if (!prev_nmi_count) goto error; + alloc_cpumask_var(&backtrace_mask, GFP_KERNEL); printk(KERN_INFO "Testing NMI watchdog ... "); #ifdef CONFIG_SMP @@ -413,14 +414,14 @@ nmi_watchdog_tick(struct pt_regs *regs, unsigned reason) touched = 1; } - if (cpu_isset(cpu, backtrace_mask)) { + if (cpumask_test_cpu(cpu, backtrace_mask)) { static DEFINE_SPINLOCK(lock); /* Serialise the printks */ spin_lock(&lock); printk(KERN_WARNING "NMI backtrace for cpu %d\n", cpu); dump_stack(); spin_unlock(&lock); - cpu_clear(cpu, backtrace_mask); + cpumask_clear_cpu(cpu, backtrace_mask); } /* Could check oops_in_progress here too, but it's safer not to */ @@ -554,10 +555,10 @@ void __trigger_all_cpu_backtrace(void) { int i; - backtrace_mask = cpu_online_map; + cpumask_copy(backtrace_mask, cpu_online_mask); /* Wait for up to 10 seconds for all CPUs to do the backtrace */ for (i = 0; i < 10 * 1000; i++) { - if (cpus_empty(backtrace_mask)) + if (cpumask_empty(backtrace_mask)) break; mdelay(1); } -- GitLab