On (04/20/17 15:11), Petr Mladek wrote:
[..]
> void printk_nmi_enter(void)
> {
> - this_cpu_or(printk_context, PRINTK_NMI_CONTEXT_MASK);
> + /*
> + * The size of the extra per-CPU buffer is limited. Use it
> + * only when really needed.
> + */
> + if (this_cpu_read(printk_context) & PRINTK_SAFE_CONTEXT_MASK ||
> + raw_spin_is_locked(&logbuf_lock)) {
can we please have && here?
[..]
> diff --git a/lib/nmi_backtrace.c b/lib/nmi_backtrace.c
> index 4e8a30d1c22f..0bc0a3535a8a 100644
> --- a/lib/nmi_backtrace.c
> +++ b/lib/nmi_backtrace.c
> @@ -86,9 +86,11 @@ void nmi_trigger_cpumask_backtrace(const cpumask_t *mask,
>
> bool nmi_cpu_backtrace(struct pt_regs *regs)
> {
> + static arch_spinlock_t lock = __ARCH_SPIN_LOCK_UNLOCKED;
> int cpu = smp_processor_id();
>
> if (cpumask_test_cpu(cpu, to_cpumask(backtrace_mask))) {
> + arch_spin_lock(&lock);
> if (regs && cpu_in_idle(instruction_pointer(regs))) {
> pr_warn("NMI backtrace for cpu %d skipped: idling at pc %#lx\n",
> cpu, instruction_pointer(regs));
> @@ -99,6 +101,7 @@ bool nmi_cpu_backtrace(struct pt_regs *regs)
> else
> dump_stack();
> }
> + arch_spin_unlock(&lock);
> cpumask_clear_cpu(cpu, to_cpumask(backtrace_mask));
> return true;
> }
can the nmi_backtrace part be a patch on its own?
-ss
