[PATCH V10 17/19] RISC-V: paravirt: pvqspinlock: Add trace point for pv_kick/wait

guoren
2023-08-02T16:52:25Z

Add trace point for pv_kick/wait, here is the output:

entries-in-buffer/entries-written: 33927/33927 #P:12

_-----=> irqs-off/BH-disabled
/ _----=> need-resched
| / _---=> hardirq/softirq
|| / _--=> preempt-depth
||| / _-=> migrate-disable
|||| / delay
TASK-PID CPU# ||||| TIMESTAMP FUNCTION
| | | ||||| | |
sh-100 [001] d..2. 28.312294: pv_wait: cpu 1 out of wfi
<idle>-0 [000] d.h4. 28.322030: pv_kick: cpu 0 kick target cpu 1
sh-100 [001] d..2. 30.982631: pv_wait: cpu 1 out of wfi
<idle>-0 [000] d.h4. 30.993289: pv_kick: cpu 0 kick target cpu 1
sh-100 [002] d..2. 44.987573: pv_wait: cpu 2 out of wfi
<idle>-0 [000] d.h4. 44.989000: pv_kick: cpu 0 kick target cpu 2
<idle>-0 [003] d.s3. 51.593978: pv_kick: cpu 3 kick target cpu 4
rcu_sched-15 [004] d..2. 51.595192: pv_wait: cpu 4 out of wfi
lock_torture_wr-115 [004] ...2. 52.656482: pv_kick: cpu 4 kick target cpu 2
lock_torture_wr-113 [002] d..2. 52.659146: pv_wait: cpu 2 out of wfi
lock_torture_wr-114 [008] d..2. 52.659507: pv_wait: cpu 8 out of wfi
lock_torture_wr-114 [008] d..2. 52.663503: pv_wait: cpu 8 out of wfi
lock_torture_wr-113 [002] ...2. 52.666128: pv_kick: cpu 2 kick target cpu 8
lock_torture_wr-114 [008] d..2. 52.667261: pv_wait: cpu 8 out of wfi
lock_torture_wr-114 [009] .n.2. 53.141515: pv_kick: cpu 9 kick target cpu 11
lock_torture_wr-113 [002] d..2. 53.143339: pv_wait: cpu 2 out of wfi
lock_torture_wr-116 [007] d..2. 53.143412: pv_wait: cpu 7 out of wfi
lock_torture_wr-118 [000] d..2. 53.143457: pv_wait: cpu 0 out of wfi
lock_torture_wr-115 [008] d..2. 53.143481: pv_wait: cpu 8 out of wfi
lock_torture_wr-117 [011] d..2. 53.143522: pv_wait: cpu 11 out of wfi
lock_torture_wr-117 [011] ...2. 53.143987: pv_kick: cpu 11 kick target cpu 8
lock_torture_wr-115 [008] ...2. 53.144269: pv_kick: cpu 8 kick target cpu 7

Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Signed-off-by: Guo Ren <guoren@kernel.org>
---
arch/riscv/kernel/paravirt.c | 8 +++
.../kernel/trace_events_filter_paravirt.h | 60 +++++++++++++++++++
2 files changed, 68 insertions(+)
create mode 100644 arch/riscv/kernel/trace_events_filter_paravirt.h

diff --git a/arch/riscv/kernel/paravirt.c b/arch/riscv/kernel/paravirt.c
index 564d64f11e4f..cc80e968ab13 100644
--- a/arch/riscv/kernel/paravirt.c
+++ b/arch/riscv/kernel/paravirt.c
@@ -134,10 +134,16 @@ int __init pv_time_init(void)
#ifdef CONFIG_PARAVIRT_SPINLOCKS
#include <asm/qspinlock_paravirt.h>

+#define CREATE_TRACE_POINTS
+#include "trace_events_filter_paravirt.h"
+
void pv_kick(int cpu)
{
sbi_ecall(SBI_EXT_PVLOCK, SBI_EXT_PVLOCK_KICK_CPU,
cpuid_to_hartid_map(cpu), 0, 0, 0, 0, 0);
+
+ trace_pv_kick(smp_processor_id(), cpu);
+
return;
}

@@ -153,6 +159,8 @@ void pv_wait(u8 *ptr, u8 val)
goto out;

wait_for_interrupt();
+
+ trace_pv_wait(smp_processor_id());
out:
local_irq_restore(flags);
}
diff --git a/arch/riscv/kernel/trace_events_filter_paravirt.h b/arch/riscv/kernel/trace_events_filter_paravirt.h
new file mode 100644
index 000000000000..9ff5aa451b12
--- /dev/null
+++ b/arch/riscv/kernel/trace_events_filter_paravirt.h
@@ -0,0 +1,60 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c), 2023 Alibaba Cloud
+ * Authors:
+ * Guo Ren <guoren@linux.alibaba.com>
+ */
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM paravirt
+
+#if !defined(_TRACE_PARAVIRT_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_PARAVIRT_H
+
+#include <linux/tracepoint.h>
+
+TRACE_EVENT(pv_kick,
+ TP_PROTO(int cpu, int target),
+ TP_ARGS(cpu, target),
+
+ TP_STRUCT__entry(
+ __field(int, cpu)
+ __field(int, target)
+ ),
+
+ TP_fast_assign(
+ __entry->cpu = cpu;
+ __entry->target = target;
+ ),
+
+ TP_printk("cpu %d kick target cpu %d",
+ __entry->cpu,
+ __entry->target
+ )
+);
+
+TRACE_EVENT(pv_wait,
+ TP_PROTO(int cpu),
+ TP_ARGS(cpu),
+
+ TP_STRUCT__entry(
+ __field(int, cpu)
+ ),
+
+ TP_fast_assign(
+ __entry->cpu = cpu;
+ ),
+
+ TP_printk("cpu %d out of wfi",
+ __entry->cpu
+ )
+);
+
+#endif /* _TRACE_PARAVIRT_H || TRACE_HEADER_MULTI_READ */
+
+#undef TRACE_INCLUDE_PATH
+#undef TRACE_INCLUDE_FILE
+#define TRACE_INCLUDE_PATH ../../../arch/riscv/kernel/
+#define TRACE_INCLUDE_FILE trace_events_filter_paravirt
+
+/* This part must be outside protection */
+#include <trace/define_trace.h>