Currently query-dirty-rate uses QEMU_CLOCK_REALTIME as
the source for start-time field. This translates to
clock_gettime(CLOCK_MONOTONIC), i.e. number of seconds
since host boot. This is not very useful. The only
reasonable use case of start-time I can imagine is to
check whether previously completed measurements are
too old or not. But this makes sense only if start-time
is reported as host wall-clock time.
This patch replaces source of start-time from
QEMU_CLOCK_REALTIME to QEMU_CLOCK_HOST.
Signed-off-by: Andrei Gudkov <gudkov.andrei@huawei.com>
---
qapi/migration.json | 4 ++--
migration/dirtyrate.c | 15 ++++++---------
2 files changed, 8 insertions(+), 11 deletions(-)
diff --git a/qapi/migration.json b/qapi/migration.json
index 8843e74b59..63deb8e387 100644
--- a/qapi/migration.json
+++ b/qapi/migration.json
@@ -1941,12 +1941,12 @@
# 1. Measurement is in progress:
#
# <- {"status": "measuring", "sample-pages": 512,
-# "mode": "page-sampling", "start-time": 3665220, "calc-time": 10}
+# "mode": "page-sampling", "start-time": 1693900454, "calc-time": 10}
#
# 2. Measurement has been completed:
#
# <- {"status": "measured", "sample-pages": 512, "dirty-rate": 108,
-# "mode": "page-sampling", "start-time": 3665220, "calc-time": 10}
+# "mode": "page-sampling", "start-time": 1693900454, "calc-time": 10}
##
{ 'command': 'query-dirty-rate', 'returns': 'DirtyRateInfo' }
diff --git a/migration/dirtyrate.c b/migration/dirtyrate.c
index bccb3515e3..0510d68765 100644
--- a/migration/dirtyrate.c
+++ b/migration/dirtyrate.c
@@ -259,11 +259,10 @@ static struct DirtyRateInfo *query_dirty_rate_info(void)
return info;
}
-static void init_dirtyrate_stat(int64_t start_time,
- struct DirtyRateConfig config)
+static void init_dirtyrate_stat(struct DirtyRateConfig config)
{
DirtyStat.dirty_rate = -1;
- DirtyStat.start_time = start_time;
+ DirtyStat.start_time = qemu_clock_get_ms(QEMU_CLOCK_HOST) / 1000;
DirtyStat.calc_time = config.sample_period_seconds;
DirtyStat.sample_pages = config.sample_pages_per_gigabytes;
@@ -600,7 +599,7 @@ static void calculate_dirtyrate_dirty_bitmap(struct DirtyRateConfig config)
record_dirtypages_bitmap(&dirty_pages, true);
start_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
- DirtyStat.start_time = start_time / 1000;
+ DirtyStat.start_time = qemu_clock_get_ms(QEMU_CLOCK_HOST) / 1000;
msec = config.sample_period_seconds * 1000;
msec = dirty_stat_wait(msec, start_time);
@@ -628,7 +627,7 @@ static void calculate_dirtyrate_dirty_ring(struct DirtyRateConfig config)
/* start log sync */
global_dirty_log_change(GLOBAL_DIRTY_DIRTY_RATE, true);
- DirtyStat.start_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME) / 1000;
+ DirtyStat.start_time = qemu_clock_get_ms(QEMU_CLOCK_HOST) / 1000;
/* calculate vcpu dirtyrate */
duration = vcpu_calculate_dirtyrate(config.sample_period_seconds * 1000,
@@ -657,6 +656,7 @@ static void calculate_dirtyrate_sample_vm(struct DirtyRateConfig config)
rcu_read_lock();
initial_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
+ DirtyStat.start_time = qemu_clock_get_ms(QEMU_CLOCK_HOST) / 1000;
if (!record_ramblock_hash_info(&block_dinfo, config, &block_count)) {
goto out;
}
@@ -664,7 +664,6 @@ static void calculate_dirtyrate_sample_vm(struct DirtyRateConfig config)
msec = config.sample_period_seconds * 1000;
msec = dirty_stat_wait(msec, initial_time);
- DirtyStat.start_time = initial_time / 1000;
DirtyStat.calc_time = msec / 1000;
rcu_read_lock();
@@ -727,7 +726,6 @@ void qmp_calc_dirty_rate(int64_t calc_time,
static struct DirtyRateConfig config;
QemuThread thread;
int ret;
- int64_t start_time;
/*
* If the dirty rate is already being measured, don't attempt to start.
@@ -799,8 +797,7 @@ void qmp_calc_dirty_rate(int64_t calc_time,
**/
dirtyrate_mode = mode;
- start_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME) / 1000;
- init_dirtyrate_stat(start_time, config);
+ init_dirtyrate_stat(config);
qemu_thread_create(&thread, "get_dirtyrate", get_dirtyrate_thread,
(void *)&config, QEMU_THREAD_DETACHED);
--
2.30.2