[PATCH]: Another latency histogram cleanup
From: yangyi
Date: Thu Sep 15 2005 - 22:47:38 EST
Hi, Ingo
This is another latency histogram cleanup, changes include:
- Remove some definitons to include/linux/latency_hist.h from kenerl/latency.c and kernel/latency_hist.c
- Eliminate most #ifedf from check_critical_timing() and check_wakup_timing()
diffstat:
include/linux/latency_hist.h | 32 ++++++++++++++++++++
kernel/latency.c | 67 ++++++++++++++-----------------------------
kernel/latency_hist.c | 12 +------
3 files changed, 57 insertions(+), 54 deletions(-)
--- /dev/null 2003-12-29 18:00:06.000000000 +0800
+++ b/include/linux/latency_hist.h 2005-09-13 10:33:40.000000000 +0800
@@ -0,0 +1,32 @@
+/*
+ * kernel/latency_hist.h
+ *
+ * Add support for histograms of preemption-off latency and
+ * interrupt-off latency and wakeup latency, it depends on
+ * Real-Time Preemption Support.
+ *
+ * Copyright (C) 2005 MontaVista Software, Inc.
+ * Yi Yang <yyang@xxxxxxxxxxxxx>
+ *
+ */
+#ifndef _LINUX_LATENCY_HIST_H_
+#define _LINUX_LATENCY_HIST_H_
+
+enum {
+ INTERRUPT_LATENCY = 0,
+ PREEMPT_LATENCY,
+ WAKEUP_LATENCY
+};
+
+#define MAX_ENTRY_NUM 10240
+#define LATENCY_TYPE_NUM 3
+
+#ifdef CONFIG_LATENCY_HIST
+extern void latency_hist(int latency_type, int cpu, unsigned long latency);
+#define latency_hist_flag 1
+#else
+#define latency_hist(a,b,c) do {} while(0)
+#define latency_hist_flag 0
+#endif /* CONFIG_LATENCY_HIST */
+
+#endif /* ifndef _LINUX_LATENCY_HIST_H_ */
--- a/kernel/latency.c.orig 2005-08-26 15:46:03.000000000 +0800
+++ b/kernel/latency.c 2005-09-13 11:00:58.000000000 +0800
@@ -20,21 +20,11 @@
#include <linux/seq_file.h>
#include <linux/interrupt.h>
#include <linux/proc_fs.h>
+#include <linux/latency_hist.h>
#include <asm/uaccess.h>
#include <asm/unistd.h>
#include <asm/rtc.h>
-
-enum {
- INTERRUPT_LATENCY,
- PREEMPT_LATENCY,
- WAKEUP_LATENCY
-};
-
-#ifdef CONFIG_LATENCY_HIST
-extern void latency_hist(int latency_type, int cpu, unsigned long latency);
-#endif /* CONFIG_LATENCY_HIST */
-
#ifdef CONFIG_CRITICAL_IRQSOFF_TIMING
# ifdef CONFIG_CRITICAL_PREEMPT_TIMING
# define irqs_off_preempt_count() preempt_count()
@@ -89,6 +79,9 @@ static cycles_t preempt_thresh;
*/
static int report_latency(cycles_t delta)
{
+ if (latency_hist_flag)
+ return 1;
+
if (preempt_thresh) {
if (delta < preempt_thresh)
return 0;
@@ -1322,10 +1315,9 @@ check_critical_timing(int cpu, struct cp
raw_local_save_flags(flags);
-#ifndef CONFIG_CRITICAL_LATENCY_HIST
if (!report_latency(delta))
goto out;
-#endif
+
____trace(cpu, TRACE_FN, tr, CALLER_ADDR0, parent_eip, 0, 0, 0, flags);
/*
* Update the timestamp, because the trace entry above
@@ -1337,6 +1329,14 @@ check_critical_timing(int cpu, struct cp
printk("bug: %016Lx < %016Lx!\n", T2, T1);
delta = T2-T0;
+ latency = cycles_to_usecs(delta);
+ latency_hist(tr->latency_type, cpu, latency);
+
+ if (latency_hist_flag) {
+ if (preempt_max_latency >= delta)
+ goto out;
+ }
+
if (tr->critical_sequence != max_sequence || down_trylock(&max_mutex))
goto out;
@@ -1348,12 +1348,6 @@ check_critical_timing(int cpu, struct cp
}
#endif
- latency = cycles_to_usecs(delta);
-
-#ifdef CONFIG_CRITICAL_LATENCY_HIST
-if (preempt_max_latency < delta) {
-#endif
-
preempt_max_latency = delta;
t0 = cycles_to_usecs(T0);
t1 = cycles_to_usecs(T1);
@@ -1387,16 +1381,8 @@ if (preempt_max_latency < delta) {
max_sequence++;
-#ifdef CONFIG_CRITICAL_LATENCY_HIST
-}
-#endif
-
up(&max_mutex);
-#ifdef CONFIG_CRITICAL_LATENCY_HIST
- latency_hist(tr->latency_type, cpu, latency);
-#endif /* CONFIG_CRITICAL_LATENCY_HIST */
-
out:
tr->critical_sequence = max_sequence;
tr->preempt_timestamp = cycles();
@@ -1684,9 +1670,7 @@ check_wakeup_timing(struct cpu_trace *tr
{
unsigned long latency, t0, t1, flags;
cycles_t T0, T1, T2, delta;
-#ifdef CONFIG_WAKEUP_LATENCY_HIST
int cpu = raw_smp_processor_id();
-#endif
if (trace_user_triggered)
return;
@@ -1705,10 +1689,9 @@ check_wakeup_timing(struct cpu_trace *tr
T0 = T1;
delta = T1-T0;
-#ifndef CONFIG_WAKEUP_LATENCY_HIST
if (!report_latency(delta))
goto out;
-#endif
+
raw_local_save_flags(flags);
____trace(smp_processor_id(), TRACE_FN, tr, CALLER_ADDR0, parent_eip, 0, 0, 0, flags);
T2 = cycles();
@@ -1716,6 +1699,14 @@ check_wakeup_timing(struct cpu_trace *tr
printk("bug2: %016Lx < %016Lx!\n", T2, T1);
delta = T2-T0;
+ latency = cycles_to_usecs(delta);
+ latency_hist(tr->latency_type, cpu, latency);
+
+ if (latency_hist_flag) {
+ if (preempt_max_latency >= delta)
+ goto out;
+ }
+
if (tr->critical_sequence != max_sequence || down_trylock(&max_mutex))
goto out;
@@ -1727,11 +1718,6 @@ check_wakeup_timing(struct cpu_trace *tr
}
#endif
- latency = cycles_to_usecs(delta);
-
-#ifdef CONFIG_WAKEUP_LATENCY_HIST
-if (preempt_max_latency < delta) {
-#endif
preempt_max_latency = delta;
t0 = cycles_to_usecs(T0);
t1 = cycles_to_usecs(T1);
@@ -1754,16 +1740,8 @@ if (preempt_max_latency < delta) {
max_sequence++;
-#ifdef CONFIG_WAKEUP_LATENCY_HIST
-}
-#endif
-
up(&max_mutex);
-#ifdef CONFIG_WAKEUP_LATENCY_HIST
- latency_hist(WAKEUP_LATENCY, cpu, latency);
-#endif
-
out:
atomic_dec(&tr->disabled);
}
@@ -1806,6 +1784,7 @@ void __trace_start_sched_wakeup(struct t
// atomic_inc(&tr->disabled);
tr->critical_sequence = max_sequence;
tr->preempt_timestamp = cycles();
+ tr->latency_type = WAKEUP_LATENCY;
tr->critical_start = CALLER_ADDR0;
_trace_cmdline(raw_smp_processor_id(), tr);
// atomic_dec(&tr->disabled);
--- a/kernel/latency_hist.c.orig 2005-09-13 11:14:17.000000000 +0800
+++ b/kernel/latency_hist.c 2005-09-13 11:19:05.000000000 +0800
@@ -5,7 +5,7 @@
* interrupt-off latency and wakeup latency, it depends on
* Real-Time Preemption Support.
*
- * Copyright (C) 2005, 2007 MontaVista Software, Inc.
+ * Copyright (C) 2005 MontaVista Software, Inc.
* Yi Yang <yyang@xxxxxxxxxxxxx>
*
*/
@@ -14,11 +14,9 @@
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <linux/percpu.h>
+#include <linux/latency_hist.h>
#include <asm/atomic.h>
-#define MAX_ENTRY_NUM 10240
-#define LATENCY_TYPE_NUM 3
-
typedef struct hist_data_struct {
atomic_t hist_mode; /* 0 log, 1 don't log */
unsigned long min_lat;
@@ -30,12 +28,6 @@ typedef struct hist_data_struct {
unsigned long long hist_array[MAX_ENTRY_NUM];
} hist_data_t;
-enum {
- INTERRUPT_LATENCY = 0,
- PREEMPT_LATENCY,
- WAKEUP_LATENCY
-};
-
static struct proc_dir_entry * latency_hist_root = NULL;
static char * latency_hist_proc_dir_root = "latency_hist";
-
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