Commit 9056be30 authored Oct 30, 2014 by Tina Ruchandani Committed by Greg Kroah-Hartman Oct 30, 2014

Staging: lustre: lnet: lnet: Better cookie gen



api-ni.c uses do_gettimeofday to get a 'cookie' or timestamp.
This patch replaces it with ktime_get_ns for the following reasons:
1. ktime_get_ns returns a __u64 which is safer than 'struct timeval'
which will overflow on 32-bit systems in year 2038 and beyond.
2. Improved resolution: nsecs instead of usecs.
3. Reduced compute: ktime_get_ns is faster than the multiply/add
   combination used in this function

Signed-off-by: Tina Ruchandani <ruchandani.tina@gmail.com>
Suggested-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent 60444139

drivers/staging/lustre/lnet/lnet/api-ni.c

+4 −11

Original line number	Diff line number	Diff line
		@@ -37,6 +37,7 @@
		#define DEBUG_SUBSYSTEM S_LNET
		#include "../../include/linux/lnet/lib-lnet.h"
		#include <linux/log2.h>
		#include <linux/ktime.h>

		#define D_LNI D_CONSOLE

		@@ -417,17 +418,9 @@ static __u64
		lnet_create_interface_cookie(void)
		{
		/* NB the interface cookie in wire handles guards against delayed
		* replies and ACKs appearing valid after reboot. Initialisation time,
		* even if it's only implemented to millisecond resolution is probably
		* easily good enough. */
		struct timeval tv;
		__u64 cookie;

		do_gettimeofday(&tv);
		cookie = tv.tv_sec;
		cookie *= 1000000;
		cookie += tv.tv_usec;
		return cookie;
		* replies and ACKs appearing valid after reboot.
		*/
		return ktime_get_ns();
		}

		static char *