Scheduler Profiling - Use Immediate Values
Use immediate values with lower d-cache hit in optimized version as a
condition for scheduler profiling call.
Depends on the Immediate values patches, applies to 2.6.23-rc4-mm1.
Signed-off-by: Mathieu Desnoyers <[EMAIL PROTECTED]>
---
drivers/kvm/svm.c | 2 +-
drivers/kvm/vmx.c | 2 +-
include/linux/profile.h | 10 ++++------
kernel/profile.c | 38 ++++++++++++++++++++++++++------------
kernel/sched.c | 3 ++-
5 files changed, 34 insertions(+), 21 deletions(-)
Index: linux-2.6-lttng/kernel/profile.c
===================================================================
--- linux-2.6-lttng.orig/kernel/profile.c 2007-09-04 11:53:23.000000000
-0400
+++ linux-2.6-lttng/kernel/profile.c 2007-09-04 12:12:16.000000000 -0400
@@ -42,9 +42,6 @@ static int (*timer_hook)(struct pt_regs
static atomic_t *prof_buffer;
static unsigned long prof_len, prof_shift;
-int prof_on __read_mostly;
-EXPORT_SYMBOL_GPL(prof_on);
-
static cpumask_t prof_cpu_mask = CPU_MASK_ALL;
#ifdef CONFIG_SMP
static DEFINE_PER_CPU(struct profile_hit *[2], cpu_profile_hits);
@@ -52,6 +49,14 @@ static DEFINE_PER_CPU(int, cpu_profile_f
static DEFINE_MUTEX(profile_flip_mutex);
#endif /* CONFIG_SMP */
+/* Immediate values */
+immediate_char_t sleep_profiling __read_mostly,
+ sched_profiling __read_mostly,
+ kvm_profiling __read_mostly,
+ cpu_profiling __read_mostly;
+EXPORT_SYMBOL_GPL(kvm_profiling);
+EXPORT_SYMBOL_GPL(cpu_profiling);
+
static int __init profile_setup(char * str)
{
static char __initdata schedstr[] = "schedule";
@@ -60,7 +65,7 @@ static int __init profile_setup(char * s
int par;
if (!strncmp(str, sleepstr, strlen(sleepstr))) {
- prof_on = SLEEP_PROFILING;
+ immediate_set_early(&sleep_profiling, 1);
if (str[strlen(sleepstr)] == ',')
str += strlen(sleepstr) + 1;
if (get_option(&str, &par))
@@ -69,7 +74,7 @@ static int __init profile_setup(char * s
"kernel sleep profiling enabled (shift: %ld)\n",
prof_shift);
} else if (!strncmp(str, schedstr, strlen(schedstr))) {
- prof_on = SCHED_PROFILING;
+ immediate_set_early(&sched_profiling, 1);
if (str[strlen(schedstr)] == ',')
str += strlen(schedstr) + 1;
if (get_option(&str, &par))
@@ -78,7 +83,7 @@ static int __init profile_setup(char * s
"kernel schedule profiling enabled (shift: %ld)\n",
prof_shift);
} else if (!strncmp(str, kvmstr, strlen(kvmstr))) {
- prof_on = KVM_PROFILING;
+ immediate_set_early(&kvm_profiling, 1);
if (str[strlen(kvmstr)] == ',')
str += strlen(kvmstr) + 1;
if (get_option(&str, &par))
@@ -88,7 +93,7 @@ static int __init profile_setup(char * s
prof_shift);
} else if (get_option(&str, &par)) {
prof_shift = par;
- prof_on = CPU_PROFILING;
+ immediate_set_early(&cpu_profiling, 1);
printk(KERN_INFO "kernel profiling enabled (shift: %ld)\n",
prof_shift);
}
@@ -99,7 +104,10 @@ __setup("profile=", profile_setup);
void __init profile_init(void)
{
- if (!prof_on)
+ if (!_immediate_read(&sleep_profiling) &&
+ !_immediate_read(&sched_profiling) &&
+ !_immediate_read(&kvm_profiling) &&
+ !_immediate_read(&cpu_profiling))
return;
/* only text is profiled */
@@ -288,7 +296,7 @@ void profile_hits(int type, void *__pc,
int i, j, cpu;
struct profile_hit *hits;
- if (prof_on != type || !prof_buffer)
+ if (!prof_buffer)
return;
pc = min((pc - (unsigned long)_stext) >> prof_shift, prof_len - 1);
i = primary = (pc & (NR_PROFILE_GRP - 1)) << PROFILE_GRPSHIFT;
@@ -398,7 +406,7 @@ void profile_hits(int type, void *__pc,
{
unsigned long pc;
- if (prof_on != type || !prof_buffer)
+ if (!prof_buffer)
return;
pc = ((unsigned long)__pc - (unsigned long)_stext) >> prof_shift;
atomic_add(nr_hits, &prof_buffer[min(pc, prof_len - 1)]);
@@ -555,7 +563,10 @@ static int __init create_hash_tables(voi
}
return 0;
out_cleanup:
- prof_on = 0;
+ immediate_set_early(&sleep_profiling, 0);
+ immediate_set_early(&sched_profiling, 0);
+ immediate_set_early(&kvm_profiling, 0);
+ immediate_set_early(&cpu_profiling, 0);
smp_mb();
on_each_cpu(profile_nop, NULL, 0, 1);
for_each_online_cpu(cpu) {
@@ -582,7 +593,10 @@ static int __init create_proc_profile(vo
{
struct proc_dir_entry *entry;
- if (!prof_on)
+ if (!_immediate_read(&sleep_profiling) &&
+ !_immediate_read(&sched_profiling) &&
+ !_immediate_read(&kvm_profiling) &&
+ !_immediate_read(&cpu_profiling))
return 0;
if (create_hash_tables())
return -1;
Index: linux-2.6-lttng/include/linux/profile.h
===================================================================
--- linux-2.6-lttng.orig/include/linux/profile.h 2007-09-04
11:53:23.000000000 -0400
+++ linux-2.6-lttng/include/linux/profile.h 2007-09-04 12:12:16.000000000
-0400
@@ -7,10 +7,12 @@
#include <linux/init.h>
#include <linux/cpumask.h>
#include <linux/cache.h>
+#include <linux/immediate.h>
#include <asm/errno.h>
-extern int prof_on __read_mostly;
+extern immediate_char_t sleep_profiling, sched_profiling, kvm_profiling,
+ cpu_profiling;
#define CPU_PROFILING 1
#define SCHED_PROFILING 2
@@ -35,11 +37,7 @@ void profile_hits(int, void *ip, unsigne
*/
static inline void profile_hit(int type, void *ip)
{
- /*
- * Speedup for the common (no profiling enabled) case:
- */
- if (unlikely(prof_on == type))
- profile_hits(type, ip, 1);
+ profile_hits(type, ip, 1);
}
#ifdef CONFIG_PROC_FS
Index: linux-2.6-lttng/kernel/sched.c
===================================================================
--- linux-2.6-lttng.orig/kernel/sched.c 2007-09-04 11:54:05.000000000 -0400
+++ linux-2.6-lttng/kernel/sched.c 2007-09-04 12:12:17.000000000 -0400
@@ -3458,7 +3458,8 @@ static inline void schedule_debug(struct
if (unlikely(in_atomic_preempt_off()) && unlikely(!prev->exit_state))
__schedule_bug(prev);
- profile_hit(SCHED_PROFILING, __builtin_return_address(0));
+ immediate_if (&sched_profiling)
+ profile_hit(SCHED_PROFILING, __builtin_return_address(0));
schedstat_inc(this_rq(), sched_cnt);
}
Index: linux-2.6-lttng/drivers/kvm/svm.c
===================================================================
--- linux-2.6-lttng.orig/drivers/kvm/svm.c 2007-09-04 11:51:53.000000000
-0400
+++ linux-2.6-lttng/drivers/kvm/svm.c 2007-09-04 12:12:17.000000000 -0400
@@ -1570,7 +1570,7 @@ again:
/*
* Profile KVM exit RIPs:
*/
- if (unlikely(prof_on == KVM_PROFILING))
+ immediate_if (&kvm_profiling)
profile_hit(KVM_PROFILING,
(void *)(unsigned long)svm->vmcb->save.rip);
Index: linux-2.6-lttng/drivers/kvm/vmx.c
===================================================================
--- linux-2.6-lttng.orig/drivers/kvm/vmx.c 2007-09-04 11:51:53.000000000
-0400
+++ linux-2.6-lttng/drivers/kvm/vmx.c 2007-09-04 12:12:17.000000000 -0400
@@ -2234,7 +2234,7 @@ again:
/*
* Profile KVM exit RIPs:
*/
- if (unlikely(prof_on == KVM_PROFILING))
+ immediate_if (&kvm_profiling)
profile_hit(KVM_PROFILING, (void *)vmcs_readl(GUEST_RIP));
r = kvm_handle_exit(kvm_run, vcpu);
--
Mathieu Desnoyers
Computer Engineering Ph.D. Student, Ecole Polytechnique de Montreal
OpenPGP key fingerprint: 8CD5 52C3 8E3C 4140 715F BA06 3F25 A8FE 3BAE 9A68
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