Use immediate values with lower d-cache hit in optimized version as a condition for scheduler profiling call. Signed-off-by: Mathieu Desnoyers --- 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 2007-08-19 16:45:04.000000000 -0400 +++ linux-2.6-lttng/kernel/profile.c 2007-08-19 18:43:52.000000000 -0400 @@ -42,9 +42,6 @@ int (*timer_hook)(struct pt_regs *) __re 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 2007-08-19 16:45:04.000000000 -0400 +++ linux-2.6-lttng/include/linux/profile.h 2007-08-19 18:43:52.000000000 -0400 @@ -7,10 +7,12 @@ #include #include #include +#include #include -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 2007-08-19 16:45:04.000000000 -0400 +++ linux-2.6-lttng/kernel/sched.c 2007-08-19 18:43:52.000000000 -0400 @@ -3395,7 +3395,8 @@ 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 2007-08-19 16:45:04.000000000 -0400 +++ linux-2.6-lttng/drivers/kvm/svm.c 2007-08-19 18:43:52.000000000 -0400 @@ -1562,7 +1562,7 @@ 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 2007-08-19 16:45:04.000000000 -0400 +++ linux-2.6-lttng/drivers/kvm/vmx.c 2007-08-19 18:43:52.000000000 -0400 @@ -2220,7 +2220,7 @@ 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 - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/