From 89bccecdda253c9a1a38921cf9266a4f9655c88c Mon Sep 17 00:00:00 2001 From: "Denis V. Lunev" Date: Thu, 5 Sep 2024 21:19:41 +0200 Subject: [PATCH] system: improve migration debug Right now migration_throttle() tracepoint lacks very important important information, i.e. no one could easily say how much the guest is throttled. This makes difficult to debug guest quality of service during migration. This patch adds one more tracepoint into cpu_throttle_set() which is actually doing this job. Signed-off-by: Denis V. Lunev CC: Peter Xu CC: Fabiano Rosas CC: Paolo Bonzini Link: https://lore.kernel.org/r/20240905191941.310592-1-den@openvz.org Signed-off-by: Peter Xu --- system/cpu-throttle.c | 3 +++ system/trace-events | 3 +++ 2 files changed, 6 insertions(+) diff --git a/system/cpu-throttle.c b/system/cpu-throttle.c index c951a6c65e..7632dc6143 100644 --- a/system/cpu-throttle.c +++ b/system/cpu-throttle.c @@ -28,6 +28,7 @@ #include "qemu/main-loop.h" #include "sysemu/cpus.h" #include "sysemu/cpu-throttle.h" +#include "trace.h" /* vcpu throttling controls */ static QEMUTimer *throttle_timer; @@ -95,6 +96,8 @@ void cpu_throttle_set(int new_throttle_pct) */ bool throttle_active = cpu_throttle_active(); + trace_cpu_throttle_set(new_throttle_pct); + /* Ensure throttle percentage is within valid range */ new_throttle_pct = MIN(new_throttle_pct, CPU_THROTTLE_PCT_MAX); new_throttle_pct = MAX(new_throttle_pct, CPU_THROTTLE_PCT_MIN); diff --git a/system/trace-events b/system/trace-events index 2ed1d59b1f..074d001e90 100644 --- a/system/trace-events +++ b/system/trace-events @@ -44,3 +44,6 @@ dirtylimit_state_finalize(void) dirtylimit_throttle_pct(int cpu_index, uint64_t pct, int64_t time_us) "CPU[%d] throttle percent: %" PRIu64 ", throttle adjust time %"PRIi64 " us" dirtylimit_set_vcpu(int cpu_index, uint64_t quota) "CPU[%d] set dirty page rate limit %"PRIu64 dirtylimit_vcpu_execute(int cpu_index, int64_t sleep_time_us) "CPU[%d] sleep %"PRIi64 " us" + +# cpu-throttle.c +cpu_throttle_set(int new_throttle_pct) "set guest CPU throttled by %d%%" -- 2.49.0