On Tue, Sep 5, 2023 at 5:19 PM Andrei Gudkov <gudkov.and...@huawei.com>
wrote:
> 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.and...@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
>
>
Reviewed-by: Hyman Huang <yong.hu...@smartx.com>
--
Best regards
