genirq: Add missing documentation for tot_count

Commit:

  1136b0728969 ("genirq: Avoid summation loops for /proc/stat")

adds a new irq_desc::tot_count field, without documenting it.
Add the missing piece of documentation.

Signed-off-by: Waiman Long <longman@redhat.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Daniel Colascione <dancol@google.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1549983253-19107-1-git-send-email-longman@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

1 files changed, 1 insertions, 0 deletions

diff --git a/include/linux/irqdesc.h b/include/linux/irqdesc.h
index 875c41b23f20..1d679feff3f6 100644
--- a/include/linux/irqdesc.h
+++ b/include/linux/irqdesc.h
@@ -28,6 +28,7 @@ struct pt_regs;
  * @core_internal_state__do_not_mess_with_it: core internal status information
  * @depth:              disable-depth, for nested irq_disable() calls
  * @wake_depth:         enable depth, for multiple irq_set_irq_wake() callers
+ * @tot_count:          stats field for non-percpu irqs
  * @irq_count:          stats field to detect stalled irqs
  * @last_unhandled:     aging timer for unhandled count
  * @irqs_unhandled:     stats field for spurious unhandled interrupts