Re: [PATCH 1/3] sched: Move the priority specific bits into a newheader file.

From: Dongsheng Yang
Date: Mon Feb 10 2014 - 20:11:06 EST


Hi Steven,

On 02/10/2014 10:09 PM, Steven Rostedt wrote:


That's why you have:

+++ b/include/linux/sched/prio.h
@@ -0,0 +1,23 @@
+#ifndef _SCHED_PRIO_H
+#define _SCHED_PRIO_H

The first time a header gets included, it checks if _SCHED_PRIO_H is
defined, if not, it defines it and continues. Otherwise it skips the
content of the file.

This is so standard practice that CPP (C Pre-Processor) optimizes this
by checking if this exists and caches it. It wont even open the file
the second time it sees it included.

Wow, yes. Thank you for your kind explanation. :)

-- Steve
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