[Patch]: latency histogram patch cleanup
From: yangyi
Date: Wed Aug 10 2005 - 20:45:50 EST
Hi, Ingo
According to your suggestion, I check your cleanup and correct some errors and modify latency type decision.
This patch corrects some latency histogram configration options name, adds
a field to cpu_trace struct, removes that ugly latenct type decision statement
block, adds a latency_type parameter to __start_critical_timing.
diffstat:
kernel/latency.c | 51 +++++++++++++++------------------------------------
lib/Kconfig.debug | 4 ++--
2 files changed, 17 insertions(+), 38 deletions(-)
--- linux-2.6.12/lib/Kconfig.debug.orig 2005-08-10 12:07:13.000000000 +0800
+++ linux-2.6.12/lib/Kconfig.debug 2005-08-10 12:07:32.000000000 +0800
@@ -180,7 +180,7 @@ config CRITICAL_PREEMPT_TIMING
enabled. This option and the irqs-off timing option can be
used together or separately.)
-config PREEMPT_OFF_LOG
+config PREEMPT_OFF_HIST
bool "non-preemptible critical section latency histogram"
default n
depends on CRITICAL_PREEMPT_TIMING
@@ -244,7 +244,7 @@ config LATENCY_TIMING
config CRITICAL_LATENCY_HIST
bool
default y
- depends on PREEMPT_OFF_LOG || INTERRUPT_OFF_LOG
+ depends on PREEMPT_OFF_HIST || INTERRUPT_OFF_HIST
config LATENCY_HIST
bool
--- linux-2.6.12/kernel/latency.c.orig 2005-08-10 12:07:24.000000000 +0800
+++ linux-2.6.12/kernel/latency.c 2005-08-10 12:08:11.000000000 +0800
@@ -25,14 +25,16 @@
#include <asm/rtc.h>
-#ifdef CONFIG_LATENCY_HIST
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
@@ -42,19 +44,6 @@ extern void latency_hist(int latency_typ
# endif
#endif
-#ifdef CONFIG_INTERRUPT_OFF_HIST
-static inline int is_interrupt_off_timing(void)
-{
- unsigned long flags;
-
- local_save_flags(flags);
-
- return (!irqs_off_preempt_count() && raw_irqs_disabled_flags(flags));
-}
-#endif
-
-#endif
-
#ifdef __i386__
static inline cycles_t cycles(void)
{
@@ -198,6 +187,7 @@ struct cpu_trace {
unsigned long critical_start, critical_end;
int critical_sequence;
int early_warning;
+ int latency_type;
#ifdef CONFIG_LATENCY_TRACE
struct trace_entry trace[MAX_TRACE];
@@ -1362,9 +1352,6 @@ check_critical_timing(int cpu, struct cp
{
unsigned long latency, t0, t1;
cycles_t T0, T1, T2, delta;
-#ifdef CONFIG_CRITICAL_LATENCY_HIST
- int latency_type;
-#endif
if (trace_user_triggered)
return;
@@ -1376,8 +1363,10 @@ check_critical_timing(int cpu, struct cp
T1 = cycles();
delta = T1-T0;
+#ifndef CONFIG_CRITICAL_LATENCY_HIST
if (!report_latency(delta))
goto out;
+#endif
____trace(cpu, TRACE_FN, tr, CALLER_ADDR0, parent_eip, 0, 0, 0);
/*
@@ -1393,11 +1382,13 @@ check_critical_timing(int cpu, struct cp
if (tr->critical_sequence != max_sequence || down_trylock(&max_mutex))
goto out;
+#ifndef CONFIG_CRITICAL_LATENCY_HIST
if (!preempt_thresh && preempt_max_latency > delta) {
printk("bug: updating %016Lx > %016Lx?\n",
preempt_max_latency, delta);
printk(" [%016Lx %016Lx %016Lx]\n", T0, T1, T2);
}
+#endif
latency = cycles_to_usecs(delta);
@@ -1445,20 +1436,7 @@ if (preempt_max_latency < delta) {
up(&max_mutex);
#ifdef CONFIG_CRITICAL_LATENCY_HIST
- latency_type = WAKEUP_LATENCY + 1;
-#ifdef CONFIG_INTERRUPT_OFF_HIST
- if (is_interrupt_off_timing())
- latency_type = INTERRUPT_LATENCY;
-#ifdef CONFIG_PREEMPT_OFF_HIST
- else
- latency_type = PREEMPT_LATENCY;
-#endif /* CONFIG_PREEMPT_OFF_HIST */
-#else
-#ifdef CONFIG_PREEMPT_OFF_HIST
- latency_type = PREEMPT_LATENCY;
-#endif /* CONFIG_PREEMPT_OFF_HIST */
-#endif /* CONFIG_INTERRUPT_OFF_HIST */
- latency_hist(latency_type, cpu, latency);
+ latency_hist(tr->latency_type, cpu, latency);
#endif /* CONFIG_CRITICAL_LATENCY_HIST */
out:
@@ -1499,7 +1477,7 @@ void notrace stop_critical_timing(void)
EXPORT_SYMBOL(stop_critical_timing);
static inline void notrace
-__start_critical_timing(unsigned long eip, unsigned long parent_eip)
+__start_critical_timing(unsigned long eip, unsigned long parent_eip, int latency_type)
{
int cpu = raw_smp_processor_id();
struct cpu_trace *tr = cpu_traces + cpu;
@@ -1514,6 +1492,7 @@ __start_critical_timing(unsigned long ei
tr->preempt_timestamp = cycles();
tr->critical_start = eip;
tr->trace_idx = 0;
+ tr->latency_type = latency_type;
_trace_cmdline(cpu, tr);
____trace(cpu, TRACE_FN, tr, eip, parent_eip, 0, 0, 0);
@@ -1548,7 +1527,7 @@ void notrace trace_irqs_off_lowlevel(voi
raw_local_save_flags(flags);
if (!irqs_off_preempt_count() && raw_irqs_disabled_flags(flags))
- __start_critical_timing(CALLER_ADDR0, 0);
+ __start_critical_timing(CALLER_ADDR0, 0, INTERRUPT_LATENCY);
}
void notrace trace_irqs_off(void)
@@ -1558,7 +1537,7 @@ void notrace trace_irqs_off(void)
raw_local_save_flags(flags);
if (!irqs_off_preempt_count() && raw_irqs_disabled_flags(flags))
- __start_critical_timing(CALLER_ADDR0, CALLER_ADDR1);
+ __start_critical_timing(CALLER_ADDR0, CALLER_ADDR1, INTERRUPT_LATENCY);
}
EXPORT_SYMBOL(trace_irqs_off);
@@ -1630,7 +1609,7 @@ void notrace add_preempt_count_ti(struct
if (!raw_irqs_disabled_flags(flags))
#endif
if (preempt_count_ti(ti) == val)
- __start_critical_timing(eip, parent_eip);
+ __start_critical_timing(eip, parent_eip, PREEMPT_LATENCY);
}
#endif
(void)eip, (void)parent_eip;
@@ -1701,7 +1680,7 @@ void notrace mask_preempt_count(unsigned
if (!raw_irqs_disabled_flags(flags))
#endif
if (preempt_count() == mask)
- __start_critical_timing(eip, parent_eip);
+ __start_critical_timing(eip, parent_eip, PREEMPT_LATENCY);
}
#endif
(void) eip, (void) parent_eip;
-
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