[PKT_SCHED]: Make clock source configurable

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@redhat.com>

4 files changed, 74 insertions, 9 deletions

diff --git a/net/sched/Kconfig b/net/sched/Kconfig
index 54817b8ec7f009..57b2cc4761e38f 100644
--- a/net/sched/Kconfig
+++ b/net/sched/Kconfig
@@ -1,6 +1,61 @@
 #
 # Traffic control configuration.
 # 
+choice
+	prompt "Packet scheduler clock source"
+	depends on NET_SCHED
+	default NET_SCH_CLK_JIFFIES
+	help
+	  Packet schedulers need a monotonic clock that increments at a static
+	  rate. The kernel provides several suitable interfaces, each with
+	  different properties:
+	  
+	  - high resolution (us or better)
+	  - fast to read (minimal locking, no i/o access)
+	  - synchronized on all processors
+	  - handles cpu clock frequency changes
+
+	  but nothing provides all of the above.
+
+config NET_SCH_CLK_JIFFIES
+	bool "Timer interrupt"
+	help
+	  Say Y here if you want to use the timer interrupt (jiffies) as clock
+	  source. This clock source is fast, synchronized on all processors and
+	  handles cpu clock frequency changes, but its resolution is too low
+	  for accurate shaping except at very low speed.
+
+config NET_SCH_CLK_GETTIMEOFDAY
+	bool "gettimeofday"
+	help
+	  Say Y here if you want to use gettimeofday as clock source. This clock
+	  source has high resolution, is synchronized on all processors and
+	  handles cpu clock frequency changes, but it is slow.
+
+	  Choose this if you need a high resolution clock source but can't use
+	  the CPU's cycle counter.
+
+config NET_SCH_CLK_CPU
+	bool "CPU cycle counter"
+	depends on X86_TSC || X86_64 || ALPHA || SPARC64 || PPC64 || IA64
+	help
+	  Say Y here if you want to use the CPU's cycle counter as clock source.
+	  This is a cheap and high resolution clock source, but on some
+	  architectures it is not synchronized on all processors and doesn't
+	  handle cpu clock frequency changes.
+
+	  The useable cycle counters are:
+
+	  	x86/x86_64	- Timestamp Counter
+		alpha		- Cycle Counter
+		sparc64		- %ticks register
+		ppc64		- Time base
+		ia64		- Interval Time Counter
+
+	  Choose this if your CPU's cycle counter is working properly.
+
+endchoice
+
 config NET_SCH_CBQ
 	tristate "CBQ packet scheduler"
 	depends on NET_SCHED
diff --git a/net/sched/sch_api.c b/net/sched/sch_api.c
index fb7c4f0b81d1bf..1ce72ab7a68964 100644
--- a/net/sched/sch_api.c
+++ b/net/sched/sch_api.c
@@ -1088,7 +1088,7 @@ static struct file_operations psched_fops = {
 };	
 #endif
 
-#if PSCHED_CLOCK_SOURCE == PSCHED_GETTIMEOFDAY
+#ifdef CONFIG_NET_SCH_CLK_GETTIMEOFDAY
 int psched_tod_diff(int delta_sec, int bound)
 {
 	int delta;
@@ -1103,7 +1103,7 @@ int psched_tod_diff(int delta_sec, int bound)
 EXPORT_SYMBOL(psched_tod_diff);
 #endif
 
-#if PSCHED_CLOCK_SOURCE == PSCHED_CPU
+#ifdef CONFIG_NET_SCH_CLK_CPU
 psched_tdiff_t psched_clock_per_hz;
 int psched_clock_scale;
 EXPORT_SYMBOL(psched_clock_per_hz);
@@ -1169,10 +1169,10 @@ static int __init pktsched_init(void)
 {
 	struct rtnetlink_link *link_p;
 
-#if PSCHED_CLOCK_SOURCE == PSCHED_CPU
+#ifdef CONFIG_NET_SCH_CLK_CPU
 	if (psched_calibrate_clock() < 0)
 		return -1;
-#elif PSCHED_CLOCK_SOURCE == PSCHED_JIFFIES
+#elif defined(CONFIG_NET_SCH_CLK_JIFFIES)
 	psched_tick_per_us = HZ<<PSCHED_JSCALE;
 	psched_us_per_tick = 1000000;
 #endif
diff --git a/net/sched/sch_hfsc.c b/net/sched/sch_hfsc.c
index ce91e23134e805..a6e559c1670d7b 100644
--- a/net/sched/sch_hfsc.c
+++ b/net/sched/sch_hfsc.c
@@ -193,7 +193,7 @@ struct hfsc_sched
 /*
  * macros
  */
-#if PSCHED_CLOCK_SOURCE == PSCHED_GETTIMEOFDAY
+#ifdef CONFIG_NET_SCH_CLK_GETTIMEOFDAY
 #include <linux/time.h>
 #undef PSCHED_GET_TIME
 #define PSCHED_GET_TIME(stamp)						\
@@ -429,10 +429,10 @@ actlist_get_minvt(struct hfsc_class *cl, u64 cur_time)
  *	ism: (psched_us/byte) << ISM_SHIFT
  *	dx: psched_us
  *
- * Time source resolution
- *  PSCHED_JIFFIES: for 48<=HZ<=1534 resolution is between 0.63us and 1.27us.
- *  PSCHED_CPU: resolution is between 0.5us and 1us.
- *  PSCHED_GETTIMEOFDAY: resolution is exactly 1us.
+ * Clock source resolution (CONFIG_NET_SCH_CLK_*)
+ *  JIFFIES: for 48<=HZ<=1534 resolution is between 0.63us and 1.27us.
+ *  CPU: resolution is between 0.5us and 1us.
+ *  GETTIMEOFDAY: resolution is exactly 1us.
  *
  * sm and ism are scaled in order to keep effective digits.
  * SM_SHIFT and ISM_SHIFT are selected to keep at least 4 effective
diff --git a/net/sched/sch_htb.c b/net/sched/sch_htb.c
index 65797b3306cccb..415369672f44dd 100644
--- a/net/sched/sch_htb.c
+++ b/net/sched/sch_htb.c
@@ -856,8 +856,13 @@ static void htb_charge_class(struct htb_sched *q,struct htb_class *cl,
 			if (net_ratelimit())
 				printk(KERN_ERR "HTB: bad diff in charge, cl=%X diff=%lX now=%Lu then=%Lu j=%lu\n",
 				       cl->classid, diff,
+#ifdef CONFIG_NET_SCH_CLK_GETTIMEOFDAY
+				       q->now.tv_sec * 1000000ULL + q->now.tv_usec,
+				       cl->t_c.tv_sec * 1000000ULL + cl->t_c.tv_usec,
+#else
 				       (unsigned long long) q->now,
 				       (unsigned long long) cl->t_c,
+#endif
 				       q->jiffies);
 			diff = 1000;
 		}
@@ -927,8 +932,13 @@ static long htb_do_events(struct htb_sched *q,int level)
 			if (net_ratelimit())
 				printk(KERN_ERR "HTB: bad diff in events, cl=%X diff=%lX now=%Lu then=%Lu j=%lu\n",
 				       cl->classid, diff,
+#ifdef CONFIG_NET_SCH_CLK_GETTIMEOFDAY
+				       q->now.tv_sec * 1000000ULL + q->now.tv_usec,
+				       cl->t_c.tv_sec * 1000000ULL + cl->t_c.tv_usec,
+#else
 				       (unsigned long long) q->now,
 				       (unsigned long long) cl->t_c,
+#endif
 				       q->jiffies);
 			diff = 1000;
 		}