On (05/04/17 17:46), Petr Mladek wrote:
[..]
> Suggested-by: Sergey Senozhatsky <sergey.senozhat...@gmail.com>
> Signed-off-by: Petr Mladek <pmla...@suse.com>
Acked-by: Sergey Senozhatsky <sergey.senozhat...@gmail.com>
a small nitpick,
[..]
> 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
> + * the main one is locked. If this CPU is not in the safe context,
> + * the lock must be taken on another CPU and we could wait for it.
> + */
> + if (raw_spin_is_locked(&logbuf_lock) &&
> + this_cpu_read(printk_context) & PRINTK_SAFE_CONTEXT_MASK) {
> + this_cpu_or(printk_context, PRINTK_NMI_CONTEXT_MASK);
could we please check `printk_context' (local to a particular CPU)
first and, if positive, then access `logbuf_lock' (which is global)?
-ss
