From: Michael Brown <mcb30@ipxe.org>
Date: Tue, 24 Jul 2012 08:52:45 +0000 (+0100)
Subject: [console] Sleep while waiting for user input
X-Git-Tag: v1.20.1~1681
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=183a70e8b783ec143e8c30296f1a7c3c7de193d7;p=thirdparty%2Fipxe.git

[console] Sleep while waiting for user input

Reduce CPU usage while waiting for user input.  This is particularly
important for virtual machines, where CPU is a shared resource.

Reported-by: Alessandro Salvatori <alessandro@embrane.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
---

diff --git a/src/core/getkey.c b/src/core/getkey.c
index f16cafa42..d69cfb44b 100644
--- a/src/core/getkey.c
+++ b/src/core/getkey.c
@@ -24,6 +24,7 @@ FILE_LICENCE ( GPL2_OR_LATER );
 #include <ipxe/process.h>
 #include <ipxe/keys.h>
 #include <ipxe/timer.h>
+#include <ipxe/nap.h>
 
 /** @file
  *
@@ -46,6 +47,7 @@ static int getchar_timeout ( unsigned long timeout ) {
 		step();
 		if ( iskey() )
 			return getchar();
+		cpu_nap();
 	}
 
 	return -1;