[patch 10/10] Scheduler profiling - Use immediate values

Mathieu Desnoyers
2007-07-03T17:08:44Z

[-- Attachment #1: profiling-use-immediate-values.patch --]
[-- Type: text/plain, Size: 6593 bytes --]

Use immediate values with lower d-cache hit in optimized version as a
condition for scheduler profiling call.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>

---
drivers/kvm/svm.c | 2 +-
drivers/kvm/vmx.c | 2 +-
include/linux/profile.h | 9 +++------
kernel/profile.c | 37 +++++++++++++++++++++++++------------
kernel/sched.c | 3 ++-
5 files changed, 32 insertions(+), 21 deletions(-)

Index: linux-2.6-lttng/kernel/profile.c
===================================================================
--- linux-2.6-lttng.orig/kernel/profile.c 2007-06-29 12:21:08.000000000 -0400
+++ linux-2.6-lttng/kernel/profile.c 2007-06-29 14:26:42.000000000 -0400
@@ -23,6 +23,7 @@
#include <linux/profile.h>
#include <linux/highmem.h>
#include <linux/mutex.h>
+#include <linux/immediate.h>
#include <asm/sections.h>
#include <asm/semaphore.h>
#include <asm/irq_regs.h>
@@ -42,9 +43,6 @@
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 +50,12 @@
static DEFINE_MUTEX(profile_flip_mutex);
#endif /* CONFIG_SMP */

+/* Immediate values */
+immediate_t __read_mostly sleep_profiling, sched_profiling, kvm_profiling,
+ cpu_profiling;
+EXPORT_SYMBOL_GPL(kvm_profiling);
+EXPORT_SYMBOL_GPL(cpu_profiling);
+
static int __init profile_setup(char * str)
{
static char __initdata schedstr[] = "schedule";
@@ -60,7 +64,7 @@
int par;

if (!strncmp(str, sleepstr, strlen(sleepstr))) {
- prof_on = SLEEP_PROFILING;
+ immediate_arm(&sleep_profiling);
if (str[strlen(sleepstr)] == ',')
str += strlen(sleepstr) + 1;
if (get_option(&str, &par))
@@ -69,7 +73,7 @@
"kernel sleep profiling enabled (shift: %ld)\n",
prof_shift);
} else if (!strncmp(str, schedstr, strlen(schedstr))) {
- prof_on = SCHED_PROFILING;
+ immediate_arm(&sched_profiling);
if (str[strlen(schedstr)] == ',')
str += strlen(schedstr) + 1;
if (get_option(&str, &par))
@@ -78,7 +82,7 @@
"kernel schedule profiling enabled (shift: %ld)\n",
prof_shift);
} else if (!strncmp(str, kvmstr, strlen(kvmstr))) {
- prof_on = KVM_PROFILING;
+ immediate_arm(&kvm_profiling);
if (str[strlen(kvmstr)] == ',')
str += strlen(kvmstr) + 1;
if (get_option(&str, &par))
@@ -88,7 +92,7 @@
prof_shift);
} else if (get_option(&str, &par)) {
prof_shift = par;
- prof_on = CPU_PROFILING;
+ immediate_arm(&cpu_profiling);
printk(KERN_INFO "kernel profiling enabled (shift: %ld)\n",
prof_shift);
}
@@ -99,7 +103,10 @@

void __init profile_init(void)
{
- if (!prof_on)
+ if (!immediate_query(&sleep_profiling) &&
+ !immediate_query(&sched_profiling) &&
+ !immediate_query(&kvm_profiling) &&
+ !immediate_query(&cpu_profiling))
return;

/* only text is profiled */
@@ -288,7 +295,7 @@
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 +405,7 @@
{
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 +562,10 @@
}
return 0;
out_cleanup:
- prof_on = 0;
+ immediate_disarm(&sleep_profiling);
+ immediate_disarm(&sched_profiling);
+ immediate_disarm(&kvm_profiling);
+ immediate_disarm(&cpu_profiling);
smp_mb();
on_each_cpu(profile_nop, NULL, 0, 1);
for_each_online_cpu(cpu) {
@@ -582,7 +592,10 @@
{
struct proc_dir_entry *entry;

- if (!prof_on)
+ if (!immediate_query(&sleep_profiling) &&
+ !immediate_query(&sched_profiling) &&
+ !immediate_query(&kvm_profiling) &&
+ !immediate_query(&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 2007-06-29 10:21:44.000000000 -0400
+++ linux-2.6-lttng/include/linux/profile.h 2007-06-29 14:26:42.000000000 -0400
@@ -10,7 +10,8 @@

#include <asm/errno.h>

-extern int prof_on __read_mostly;
+extern immediate_t __read_mostly sleep_profiling, sched_profiling, kvm_profiling,
+ cpu_profiling;

#define CPU_PROFILING 1
#define SCHED_PROFILING 2
@@ -35,11 +36,7 @@
*/
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 2007-06-29 14:16:23.000000000 -0400
+++ linux-2.6-lttng/kernel/sched.c 2007-06-29 14:27:26.000000000 -0400
@@ -3241,7 +3241,8 @@
if (unlikely(in_atomic_preempt_off()) && unlikely(!prev->exit_state))
__schedule_bug(prev);

- profile_hit(SCHED_PROFILING, __builtin_return_address(0));
+ if (unlikely(immediate(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 2007-06-29 12:27:40.000000000 -0400
+++ linux-2.6-lttng/drivers/kvm/svm.c 2007-06-29 14:26:42.000000000 -0400
@@ -1654,7 +1654,7 @@
/*
* Profile KVM exit RIPs:
*/
- if (unlikely(prof_on == KVM_PROFILING))
+ if (unlikely(immediate(kvm_profiling)))
profile_hit(KVM_PROFILING,
(void *)(unsigned long)vcpu->svm->vmcb->save.rip);

Index: linux-2.6-lttng/drivers/kvm/vmx.c
===================================================================
--- linux-2.6-lttng.orig/drivers/kvm/vmx.c 2007-06-29 12:27:40.000000000 -0400
+++ linux-2.6-lttng/drivers/kvm/vmx.c 2007-06-29 14:26:42.000000000 -0400
@@ -2156,7 +2156,7 @@
/*
* Profile KVM exit RIPs:
*/
- if (unlikely(prof_on == KVM_PROFILING))
+ if (unlikely(immediate(kvm_profiling)))
profile_hit(KVM_PROFILING, (void *)vmcs_readl(GUEST_RIP));

vcpu->launched = 1;

--
Mathieu Desnoyers
Computer Engineering Ph.D. Student, Ecole Polytechnique de Montreal
OpenPGP key fingerprint: 8CD5 52C3 8E3C 4140 715F BA06 3F25 A8FE 3BAE 9A68