Commit-ID: 19a3110150d87093ebf240d4268507e6c17e5b46
Gitweb: http://git.kernel.org/tip/19a3110150d87093ebf240d4268507e6c17e5b46
Author: "Rusty Russell" <rusty@xxxxxxxxxxxxxxx>
AuthorDate: Thu, 12 Mar 2009 14:45:47 +1030
Commit: Rusty Russell <rusty@xxxxxxxxxxxxxxx>
CommitDate: Thu, 12 Mar 2009 14:45:47 +1030
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 <rusty@xxxxxxxxxxxxxxx>
---
arch/x86/kernel/apic/nmi.c | 11 ++++++-----
1 files changed, 6 insertions(+), 5 deletions(-)
diff --git a/arch/x86/kernel/apic/nmi.c b/arch/x86/kernel/apic/nmi.c
index bdfad80..d6bd624 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);
}
--
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