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/kvm_main.c | 3 ++- include/linux/profile.h | 5 +++-- kernel/profile.c | 22 +++++++++++----------- kernel/sched_fair.c | 6 +----- 4 files changed, 17 insertions(+), 19 deletions(-) Index: linux-2.6-lttng/kernel/profile.c =================================================================== --- linux-2.6-lttng.orig/kernel/profile.c 2007-11-13 09:48:36.000000000 -0500 +++ linux-2.6-lttng/kernel/profile.c 2007-11-13 09:48:37.000000000 -0500 @@ -42,8 +42,8 @@ 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); +DEFINE_IMMEDIATE(char, prof_on) __read_mostly; +EXPORT_IMMEDIATE_SYMBOL_GPL(prof_on); static cpumask_t prof_cpu_mask = CPU_MASK_ALL; #ifdef CONFIG_SMP @@ -61,7 +61,7 @@ static int __init profile_setup(char * s if (!strncmp(str, sleepstr, strlen(sleepstr))) { #ifdef CONFIG_SCHEDSTATS - prof_on = SLEEP_PROFILING; + immediate_set(prof_on, SLEEP_PROFILING); if (str[strlen(sleepstr)] == ',') str += strlen(sleepstr) + 1; if (get_option(&str, &par)) @@ -74,7 +74,7 @@ static int __init profile_setup(char * s "kernel sleep profiling requires CONFIG_SCHEDSTATS\n"); #endif /* CONFIG_SCHEDSTATS */ } else if (!strncmp(str, schedstr, strlen(schedstr))) { - prof_on = SCHED_PROFILING; + immediate_set(prof_on, SCHED_PROFILING); if (str[strlen(schedstr)] == ',') str += strlen(schedstr) + 1; if (get_option(&str, &par)) @@ -83,7 +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(prof_on, KVM_PROFILING); if (str[strlen(kvmstr)] == ',') str += strlen(kvmstr) + 1; if (get_option(&str, &par)) @@ -93,7 +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(prof_on, CPU_PROFILING); printk(KERN_INFO "kernel profiling enabled (shift: %ld)\n", prof_shift); } @@ -104,7 +104,7 @@ __setup("profile=", profile_setup); void __init profile_init(void) { - if (!prof_on) + if (!_immediate_read(prof_on)) return; /* only text is profiled */ @@ -293,7 +293,7 @@ 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; @@ -403,7 +403,7 @@ 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)]); @@ -560,7 +560,7 @@ static int __init create_hash_tables(voi } return 0; out_cleanup: - prof_on = 0; + immediate_set(prof_on, 0); smp_mb(); on_each_cpu(profile_nop, NULL, 0, 1); for_each_online_cpu(cpu) { @@ -587,7 +587,7 @@ static int __init create_proc_profile(vo { struct proc_dir_entry *entry; - if (!prof_on) + if (!_immediate_read(prof_on)) 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 2007-11-13 09:48:36.000000000 -0500 +++ linux-2.6-lttng/include/linux/profile.h 2007-11-13 09:48:37.000000000 -0500 @@ -7,10 +7,11 @@ #include #include #include +#include #include -extern int prof_on __read_mostly; +DECLARE_IMMEDIATE(char, prof_on) __read_mostly; #define CPU_PROFILING 1 #define SCHED_PROFILING 2 @@ -38,7 +39,7 @@ static inline void profile_hit(int type, /* * Speedup for the common (no profiling enabled) case: */ - if (unlikely(prof_on == type)) + if (unlikely(immediate_read(prof_on) == type)) profile_hits(type, ip, 1); } Index: linux-2.6-lttng/drivers/kvm/kvm_main.c =================================================================== --- linux-2.6-lttng.orig/drivers/kvm/kvm_main.c 2007-11-13 09:48:36.000000000 -0500 +++ linux-2.6-lttng/drivers/kvm/kvm_main.c 2007-11-13 09:48:37.000000000 -0500 @@ -2054,7 +2054,8 @@ again: /* * Profile KVM exit RIPs: */ - if (unlikely(prof_on == KVM_PROFILING)) { + + if (unlikely(immediate_read(prof_on) == KVM_PROFILING)) { kvm_x86_ops->cache_regs(vcpu); profile_hit(KVM_PROFILING, (void *)vcpu->rip); } Index: linux-2.6-lttng/kernel/sched_fair.c =================================================================== --- linux-2.6-lttng.orig/kernel/sched_fair.c 2007-11-13 09:48:36.000000000 -0500 +++ linux-2.6-lttng/kernel/sched_fair.c 2007-11-13 09:48:37.000000000 -0500 @@ -455,12 +455,8 @@ static void enqueue_sleeper(struct cfs_r * get a milliseconds-range estimation of the amount of * time that the task spent sleeping: */ - if (unlikely(prof_on == SLEEP_PROFILING)) { - struct task_struct *tsk = task_of(se); - - profile_hits(SLEEP_PROFILING, (void *)get_wchan(tsk), + profile_hits(SLEEP_PROFILING, (void *)get_wchan(task_of(se)), delta >> 20); - } } #endif } -- 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/