diff options
| -rw-r--r-- | arch/arm64/kernel/perf_debug.c | 1 | ||||
| -rw-r--r-- | arch/arm64/kernel/perf_trace_counters.c | 19 | ||||
| -rw-r--r-- | arch/arm64/kernel/perf_trace_counters.h | 11 |
3 files changed, 14 insertions, 17 deletions
diff --git a/arch/arm64/kernel/perf_debug.c b/arch/arm64/kernel/perf_debug.c index f4414c83e89f..3ad3e11d246b 100644 --- a/arch/arm64/kernel/perf_debug.c +++ b/arch/arm64/kernel/perf_debug.c @@ -28,6 +28,7 @@ static char *descriptions = " 6 Perf: arm64: Add debugfs node to clear PMU\n" " 7 Perf: arm64: Update PMU force reset\n" "10 Perf: arm64: tracectr: initialize counts after hotplug\n" + "11 Perf: arm64: Refine disable/enable in tracecounters\n" ; static ssize_t desc_read(struct file *fp, char __user *buf, diff --git a/arch/arm64/kernel/perf_trace_counters.c b/arch/arm64/kernel/perf_trace_counters.c index 779337a53a1e..ffcf3d00bd5d 100644 --- a/arch/arm64/kernel/perf_trace_counters.c +++ b/arch/arm64/kernel/perf_trace_counters.c @@ -19,6 +19,7 @@ static unsigned int tp_pid_state; +DEFINE_PER_CPU(u32, cntenset_val); DEFINE_PER_CPU(u32, previous_ccnt); DEFINE_PER_CPU(u32[NUM_L1_CTRS], previous_l1_cnts); DEFINE_PER_CPU(u32, old_pid); @@ -39,14 +40,10 @@ static struct notifier_block tracectr_cpu_hotplug_notifier_block = { .notifier_call = tracectr_cpu_hotplug_notifier, }; -static void setup_prev_cnts(u32 cpu) +static void setup_prev_cnts(u32 cpu, u32 cnten_val) { int i; - u32 cnten_val; - asm volatile("mrs %0, pmcntenset_el0" : "=r" (cnten_val)); - /* Disable all the counters that were enabled */ - asm volatile("msr pmcntenclr_el0, %0" : : "r" (cnten_val)); if (cnten_val & CC) asm volatile("mrs %0, pmccntr_el0" : "=r"(per_cpu(previous_ccnt, cpu))); @@ -61,13 +58,12 @@ static void setup_prev_cnts(u32 cpu) : "=r"(per_cpu(previous_l1_cnts[i], cpu))); } } - /* Enable all the counters that were disabled */ - asm volatile("msr pmcntenset_el0, %0" : : "r" (cnten_val)); } void tracectr_notifier(void *ignore, struct task_struct *prev, struct task_struct *next) { + u32 cnten_val; int current_pid; u32 cpu = task_thread_info(next)->cpu; @@ -75,14 +71,21 @@ void tracectr_notifier(void *ignore, struct task_struct *prev, return; current_pid = next->pid; if (per_cpu(old_pid, cpu) != -1) { + asm volatile("mrs %0, pmcntenset_el0" : "=r" (cnten_val)); + per_cpu(cntenset_val, cpu) = cnten_val; + /* Disable all the counters that were enabled */ + asm volatile("msr pmcntenclr_el0, %0" : : "r" (cnten_val)); if (per_cpu(hotplug_flag, cpu) == 1) { per_cpu(hotplug_flag, cpu) = 0; - setup_prev_cnts(cpu); + setup_prev_cnts(cpu, cnten_val); } else { trace_sched_switch_with_ctrs(per_cpu(old_pid, cpu), current_pid); } + + /* Enable all the counters that were disabled */ + asm volatile("msr pmcntenset_el0, %0" : : "r" (cnten_val)); } per_cpu(old_pid, cpu) = current_pid; } diff --git a/arch/arm64/kernel/perf_trace_counters.h b/arch/arm64/kernel/perf_trace_counters.h index b0cc9b8c6d13..d686e928e5df 100644 --- a/arch/arm64/kernel/perf_trace_counters.h +++ b/arch/arm64/kernel/perf_trace_counters.h @@ -29,6 +29,7 @@ #include <linux/cpumask.h> #include <linux/tracepoint.h> +DECLARE_PER_CPU(u32, cntenset_val); DECLARE_PER_CPU(u32, previous_ccnt); DECLARE_PER_CPU(u32[NUM_L1_CTRS], previous_l1_cnts); TRACE_EVENT(sched_switch_with_ctrs, @@ -59,13 +60,8 @@ TRACE_EVENT(sched_switch_with_ctrs, __entry->old_pid = prev; __entry->new_pid = next; + cnten_val = per_cpu(cntenset_val, cpu); - /* Read PMCNTENSET */ - asm volatile("mrs %0, pmcntenset_el0" - : "=r" (cnten_val)); - /* Disable all the counters that were enabled */ - asm volatile("msr pmcntenclr_el0, %0" - : : "r" (cnten_val)); if (cnten_val & CC) { asm volatile("mrs %0, pmccntr_el0" : "=r" (total_ccnt)); @@ -90,9 +86,6 @@ TRACE_EVENT(sched_switch_with_ctrs, } else delta_l1_cnts[i] = 0; } - /* Enable all the counters that were disabled */ - asm volatile("msr pmcntenset_el0, %0" - : : "r" (cnten_val)); __entry->ctr0 = delta_l1_cnts[0]; __entry->ctr1 = delta_l1_cnts[1]; |