diff options
| -rw-r--r-- | migration/dirtyrate.c | 107 | ||||
| -rw-r--r-- | migration/dirtyrate.h | 12 | ||||
| -rw-r--r-- | qapi/migration.json | 58 |
3 files changed, 128 insertions, 49 deletions
diff --git a/migration/dirtyrate.c b/migration/dirtyrate.c index bccb3515e3..a461b28bb5 100644 --- a/migration/dirtyrate.c +++ b/migration/dirtyrate.c @@ -189,10 +189,9 @@ retry: return duration; } -static bool is_sample_period_valid(int64_t sec) +static bool is_calc_time_valid(int64_t msec) { - if (sec < MIN_FETCH_DIRTYRATE_TIME_SEC || - sec > MAX_FETCH_DIRTYRATE_TIME_SEC) { + if ((msec < MIN_CALC_TIME_MS) || (msec > MAX_CALC_TIME_MS)) { return false; } @@ -216,7 +215,39 @@ static int dirtyrate_set_state(int *state, int old_state, int new_state) } } -static struct DirtyRateInfo *query_dirty_rate_info(void) +/* Decimal power of given time unit relative to one second */ +static int time_unit_to_power(TimeUnit time_unit) +{ + switch (time_unit) { + case TIME_UNIT_SECOND: + return 0; + case TIME_UNIT_MILLISECOND: + return -3; + default: + assert(false); /* unreachable */ + return 0; + } +} + +static int64_t convert_time_unit(int64_t value, TimeUnit unit_from, + TimeUnit unit_to) +{ + int power = time_unit_to_power(unit_from) - + time_unit_to_power(unit_to); + while (power < 0) { + value /= 10; + power += 1; + } + while (power > 0) { + value *= 10; + power -= 1; + } + return value; +} + + +static struct DirtyRateInfo * +query_dirty_rate_info(TimeUnit calc_time_unit) { int i; int64_t dirty_rate = DirtyStat.dirty_rate; @@ -225,7 +256,10 @@ static struct DirtyRateInfo *query_dirty_rate_info(void) info->status = CalculatingState; info->start_time = DirtyStat.start_time; - info->calc_time = DirtyStat.calc_time; + info->calc_time = convert_time_unit(DirtyStat.calc_time_ms, + TIME_UNIT_MILLISECOND, + calc_time_unit); + info->calc_time_unit = calc_time_unit; info->sample_pages = DirtyStat.sample_pages; info->mode = dirtyrate_mode; @@ -264,7 +298,7 @@ static void init_dirtyrate_stat(int64_t start_time, { DirtyStat.dirty_rate = -1; DirtyStat.start_time = start_time; - DirtyStat.calc_time = config.sample_period_seconds; + DirtyStat.calc_time_ms = config.calc_time_ms; DirtyStat.sample_pages = config.sample_pages_per_gigabytes; switch (config.mode) { @@ -574,7 +608,6 @@ static inline void dirtyrate_manual_reset_protect(void) static void calculate_dirtyrate_dirty_bitmap(struct DirtyRateConfig config) { - int64_t msec = 0; int64_t start_time; DirtyPageRecord dirty_pages; @@ -602,9 +635,7 @@ static void calculate_dirtyrate_dirty_bitmap(struct DirtyRateConfig config) start_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME); DirtyStat.start_time = start_time / 1000; - msec = config.sample_period_seconds * 1000; - msec = dirty_stat_wait(msec, start_time); - DirtyStat.calc_time = msec / 1000; + DirtyStat.calc_time_ms = dirty_stat_wait(config.calc_time_ms, start_time); /* * do two things. @@ -615,12 +646,12 @@ static void calculate_dirtyrate_dirty_bitmap(struct DirtyRateConfig config) record_dirtypages_bitmap(&dirty_pages, false); - DirtyStat.dirty_rate = do_calculate_dirtyrate(dirty_pages, msec); + DirtyStat.dirty_rate = do_calculate_dirtyrate(dirty_pages, + DirtyStat.calc_time_ms); } static void calculate_dirtyrate_dirty_ring(struct DirtyRateConfig config) { - int64_t duration; uint64_t dirtyrate = 0; uint64_t dirtyrate_sum = 0; int i = 0; @@ -631,12 +662,10 @@ static void calculate_dirtyrate_dirty_ring(struct DirtyRateConfig config) DirtyStat.start_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME) / 1000; /* calculate vcpu dirtyrate */ - duration = vcpu_calculate_dirtyrate(config.sample_period_seconds * 1000, - &DirtyStat.dirty_ring, - GLOBAL_DIRTY_DIRTY_RATE, - true); - - DirtyStat.calc_time = duration / 1000; + DirtyStat.calc_time_ms = vcpu_calculate_dirtyrate(config.calc_time_ms, + &DirtyStat.dirty_ring, + GLOBAL_DIRTY_DIRTY_RATE, + true); /* calculate vm dirtyrate */ for (i = 0; i < DirtyStat.dirty_ring.nvcpu; i++) { @@ -652,7 +681,6 @@ static void calculate_dirtyrate_sample_vm(struct DirtyRateConfig config) { struct RamblockDirtyInfo *block_dinfo = NULL; int block_count = 0; - int64_t msec = 0; int64_t initial_time; rcu_read_lock(); @@ -662,17 +690,16 @@ static void calculate_dirtyrate_sample_vm(struct DirtyRateConfig config) } rcu_read_unlock(); - msec = config.sample_period_seconds * 1000; - msec = dirty_stat_wait(msec, initial_time); + DirtyStat.calc_time_ms = dirty_stat_wait(config.calc_time_ms, + initial_time); DirtyStat.start_time = initial_time / 1000; - DirtyStat.calc_time = msec / 1000; rcu_read_lock(); if (!compare_page_hash_info(block_dinfo, block_count)) { goto out; } - update_dirtyrate(msec); + update_dirtyrate(DirtyStat.calc_time_ms); out: rcu_read_unlock(); @@ -718,6 +745,8 @@ void *get_dirtyrate_thread(void *arg) } void qmp_calc_dirty_rate(int64_t calc_time, + bool has_calc_time_unit, + TimeUnit calc_time_unit, bool has_sample_pages, int64_t sample_pages, bool has_mode, @@ -737,10 +766,15 @@ void qmp_calc_dirty_rate(int64_t calc_time, return; } - if (!is_sample_period_valid(calc_time)) { - error_setg(errp, "calc-time is out of range[%d, %d].", - MIN_FETCH_DIRTYRATE_TIME_SEC, - MAX_FETCH_DIRTYRATE_TIME_SEC); + int64_t calc_time_ms = convert_time_unit( + calc_time, + has_calc_time_unit ? calc_time_unit : TIME_UNIT_SECOND, + TIME_UNIT_MILLISECOND + ); + + if (!is_calc_time_valid(calc_time_ms)) { + error_setg(errp, "Calculation time is out of range [%dms, %dms].", + MIN_CALC_TIME_MS, MAX_CALC_TIME_MS); return; } @@ -787,7 +821,7 @@ void qmp_calc_dirty_rate(int64_t calc_time, return; } - config.sample_period_seconds = calc_time; + config.calc_time_ms = calc_time_ms; config.sample_pages_per_gigabytes = sample_pages; config.mode = mode; @@ -806,14 +840,18 @@ void qmp_calc_dirty_rate(int64_t calc_time, (void *)&config, QEMU_THREAD_DETACHED); } -struct DirtyRateInfo *qmp_query_dirty_rate(Error **errp) + +struct DirtyRateInfo *qmp_query_dirty_rate(bool has_calc_time_unit, + TimeUnit calc_time_unit, + Error **errp) { - return query_dirty_rate_info(); + return query_dirty_rate_info( + has_calc_time_unit ? calc_time_unit : TIME_UNIT_SECOND); } void hmp_info_dirty_rate(Monitor *mon, const QDict *qdict) { - DirtyRateInfo *info = query_dirty_rate_info(); + DirtyRateInfo *info = query_dirty_rate_info(TIME_UNIT_SECOND); monitor_printf(mon, "Status: %s\n", DirtyRateStatus_str(info->status)); @@ -873,8 +911,11 @@ void hmp_calc_dirty_rate(Monitor *mon, const QDict *qdict) mode = DIRTY_RATE_MEASURE_MODE_DIRTY_RING; } - qmp_calc_dirty_rate(sec, has_sample_pages, sample_pages, true, - mode, &err); + qmp_calc_dirty_rate(sec, /* calc-time */ + false, TIME_UNIT_SECOND, /* calc-time-unit */ + has_sample_pages, sample_pages, + true, mode, + &err); if (err) { hmp_handle_error(mon, err); return; diff --git a/migration/dirtyrate.h b/migration/dirtyrate.h index 594a5c0bb6..869c060941 100644 --- a/migration/dirtyrate.h +++ b/migration/dirtyrate.h @@ -31,10 +31,12 @@ #define MIN_RAMBLOCK_SIZE 128 /* - * Take 1s as minimum time for calculation duration + * Allowed range for dirty page rate calculation (in milliseconds). + * Lower limit relates to the smallest realistic downtime it + * makes sense to impose on migration. */ -#define MIN_FETCH_DIRTYRATE_TIME_SEC 1 -#define MAX_FETCH_DIRTYRATE_TIME_SEC 60 +#define MIN_CALC_TIME_MS 50 +#define MAX_CALC_TIME_MS 60000 /* * Take 1/16 pages in 1G as the maxmum sample page count @@ -44,7 +46,7 @@ struct DirtyRateConfig { uint64_t sample_pages_per_gigabytes; /* sample pages per GB */ - int64_t sample_period_seconds; /* time duration between two sampling */ + int64_t calc_time_ms; /* desired calculation time (in milliseconds) */ DirtyRateMeasureMode mode; /* mode of dirtyrate measurement */ }; @@ -73,7 +75,7 @@ typedef struct SampleVMStat { struct DirtyRateStat { int64_t dirty_rate; /* dirty rate in MB/s */ int64_t start_time; /* calculation start time in units of second */ - int64_t calc_time; /* time duration of two sampling in units of second */ + int64_t calc_time_ms; /* actual calculation time (in milliseconds) */ uint64_t sample_pages; /* sample pages per GB */ union { SampleVMStat page_sampling; diff --git a/qapi/migration.json b/qapi/migration.json index 8843e74b59..1717aa4bbd 100644 --- a/qapi/migration.json +++ b/qapi/migration.json @@ -1837,6 +1837,21 @@ 'data': ['page-sampling', 'dirty-ring', 'dirty-bitmap'] } ## +# @TimeUnit: +# +# Specifies unit in which time-related value is specified. +# +# @second: value is in seconds +# +# @millisecond: value is in milliseconds +# +# Since 8.2 +# +## +{ 'enum': 'TimeUnit', + 'data': ['second', 'millisecond'] } + +## # @DirtyRateInfo: # # Information about measured dirty page rate. @@ -1848,8 +1863,10 @@ # # @start-time: start time in units of second for calculation # -# @calc-time: time period for which dirty page rate was measured -# (in seconds) +# @calc-time: time period for which dirty page rate was measured, +# expressed and rounded down to @calc-time-unit. +# +# @calc-time-unit: time unit of @calc-time (Since 8.2) # # @sample-pages: number of sampled pages per GiB of guest memory. # Valid only in page-sampling mode (Since 6.1) @@ -1866,6 +1883,7 @@ 'status': 'DirtyRateStatus', 'start-time': 'int64', 'calc-time': 'int64', + 'calc-time-unit': 'TimeUnit', 'sample-pages': 'uint64', 'mode': 'DirtyRateMeasureMode', '*vcpu-dirty-rate': [ 'DirtyRateVcpu' ] } } @@ -1901,12 +1919,16 @@ # This mode tracks page modification per each vCPU separately. It # requires that KVM accelerator property "dirty-ring-size" is set. # -# @calc-time: time period in units of second for which dirty page rate -# is calculated. Note that larger @calc-time values will -# typically result in smaller dirty page rates because page -# dirtying is a one-time event. Once some page is counted as -# dirty during @calc-time period, further writes to this page will -# not increase dirty page rate anymore. +# @calc-time: time period for which dirty page rate is calculated. +# By default it is specified in seconds, but the unit can be set +# explicitly with @calc-time-unit. Note that larger @calc-time +# values will typically result in smaller dirty page rates because +# page dirtying is a one-time event. Once some page is counted +# as dirty during @calc-time period, further writes to this page +# will not increase dirty page rate anymore. +# +# @calc-time-unit: time unit in which @calc-time is specified. +# By default it is seconds. (Since 8.2) # # @sample-pages: number of sampled pages per each GiB of guest memory. # Default value is 512. For 4KiB guest pages this corresponds to @@ -1924,8 +1946,16 @@ # -> {"execute": "calc-dirty-rate", "arguments": {"calc-time": 1, # 'sample-pages': 512} } # <- { "return": {} } +# +# Measure dirty rate using dirty bitmap for 500 milliseconds: +# +# -> {"execute": "calc-dirty-rate", "arguments": {"calc-time": 500, +# "calc-time-unit": "millisecond", "mode": "dirty-bitmap"} } +# +# <- { "return": {} } ## { 'command': 'calc-dirty-rate', 'data': {'calc-time': 'int64', + '*calc-time-unit': 'TimeUnit', '*sample-pages': 'int', '*mode': 'DirtyRateMeasureMode'} } @@ -1934,6 +1964,9 @@ # # Query results of the most recent invocation of @calc-dirty-rate. # +# @calc-time-unit: time unit in which to report calculation time. +# By default it is reported in seconds. (Since 8.2) +# # Since: 5.2 # # Examples: @@ -1941,14 +1974,17 @@ # 1. Measurement is in progress: # # <- {"status": "measuring", "sample-pages": 512, -# "mode": "page-sampling", "start-time": 3665220, "calc-time": 10} +# "mode": "page-sampling", "start-time": 3665220, "calc-time": 10, +# "calc-time-unit": "second"} # # 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": 3665220, "calc-time": 10, +# "calc-time-unit": "second"} ## -{ 'command': 'query-dirty-rate', 'returns': 'DirtyRateInfo' } +{ 'command': 'query-dirty-rate', 'data': {'*calc-time-unit': 'TimeUnit' }, + 'returns': 'DirtyRateInfo' } ## # @DirtyLimitInfo: |