From: Hyman Huang(黄勇) <huangy81@chinatelecom.cn>
introduce optional sample-pages argument in calc-dirty-rate,
making sample page count per GB configurable so that more
accurate dirtyrate can be calculated.
Signed-off-by: Hyman Huang(黄勇) <huangy81@chinatelecom.cn>
---
migration/dirtyrate.c | 32 ++++++++++++++++++++++++++++----
migration/dirtyrate.h | 8 +++++++-
qapi/migration.json | 13 ++++++++++---
3 files changed, 45 insertions(+), 8 deletions(-)
diff --git a/migration/dirtyrate.c b/migration/dirtyrate.c
index ccb9814..43a531c 100644
--- a/migration/dirtyrate.c
+++ b/migration/dirtyrate.c
@@ -48,6 +48,16 @@ static bool is_sample_period_valid(int64_t sec)
return true;
}
+static bool is_sample_pages_valid(int64_t pages)
+{
+ if (pages < MIN_SAMPLE_PAGE_COUNT ||
+ pages > MAX_SAMPLE_PAGE_COUNT) {
+ return false;
+ }
+
+ return true;
+}
+
static int dirtyrate_set_state(int *state, int old_state, int new_state)
{
assert(new_state < DIRTY_RATE_STATUS__MAX);
@@ -72,13 +82,15 @@ static struct DirtyRateInfo *query_dirty_rate_info(void)
info->status = CalculatingState;
info->start_time = DirtyStat.start_time;
info->calc_time = DirtyStat.calc_time;
+ info->sample_pages = DirtyStat.sample_pages;
trace_query_dirty_rate_info(DirtyRateStatus_str(CalculatingState));
return info;
}
-static void init_dirtyrate_stat(int64_t start_time, int64_t calc_time)
+static void init_dirtyrate_stat(int64_t start_time, int64_t calc_time,
+ uint64_t sample_pages)
{
DirtyStat.total_dirty_samples = 0;
DirtyStat.total_sample_count = 0;
@@ -86,6 +98,7 @@ static void init_dirtyrate_stat(int64_t start_time, int64_t
calc_time)
DirtyStat.dirty_rate = -1;
DirtyStat.start_time = start_time;
DirtyStat.calc_time = calc_time;
+ DirtyStat.sample_pages = sample_pages;
}
static void update_dirtyrate_stat(struct RamblockDirtyInfo *info)
@@ -361,6 +374,7 @@ void *get_dirtyrate_thread(void *arg)
int ret;
int64_t start_time;
int64_t calc_time;
+ uint64_t sample_pages;
ret = dirtyrate_set_state(&CalculatingState, DIRTY_RATE_STATUS_UNSTARTED,
DIRTY_RATE_STATUS_MEASURING);
@@ -371,7 +385,8 @@ void *get_dirtyrate_thread(void *arg)
start_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME) / 1000;
calc_time = config.sample_period_seconds;
- init_dirtyrate_stat(start_time, calc_time);
+ sample_pages = config.sample_pages_per_gigabytes;
+ init_dirtyrate_stat(start_time, calc_time, sample_pages);
calculate_dirtyrate(config);
@@ -383,7 +398,8 @@ void *get_dirtyrate_thread(void *arg)
return NULL;
}
-void qmp_calc_dirty_rate(int64_t calc_time, Error **errp)
+void qmp_calc_dirty_rate(int64_t calc_time, bool has_sample_pages,
+ int64_t sample_pages, Error **errp)
{
static struct DirtyRateConfig config;
QemuThread thread;
@@ -404,6 +420,13 @@ void qmp_calc_dirty_rate(int64_t calc_time, Error **errp)
return;
}
+ if (has_sample_pages && !is_sample_pages_valid(sample_pages)) {
+ error_setg(errp, "sample-pages is out of range[%d, %d].",
+ MIN_SAMPLE_PAGE_COUNT,
+ MAX_SAMPLE_PAGE_COUNT);
+ return;
+ }
+
/*
* Init calculation state as unstarted.
*/
@@ -415,7 +438,8 @@ void qmp_calc_dirty_rate(int64_t calc_time, Error **errp)
}
config.sample_period_seconds = calc_time;
- config.sample_pages_per_gigabytes = DIRTYRATE_DEFAULT_SAMPLE_PAGES;
+ config.sample_pages_per_gigabytes =
+ has_sample_pages ? sample_pages : DIRTYRATE_DEFAULT_SAMPLE_PAGES;
qemu_thread_create(&thread, "get_dirtyrate", get_dirtyrate_thread,
(void *)&config, QEMU_THREAD_DETACHED);
}
diff --git a/migration/dirtyrate.h b/migration/dirtyrate.h
index 6ec4295..5f987e2 100644
--- a/migration/dirtyrate.h
+++ b/migration/dirtyrate.h
@@ -15,7 +15,6 @@
/*
* Sample 512 pages per GB as default.
- * TODO: Make it configurable.
*/
#define DIRTYRATE_DEFAULT_SAMPLE_PAGES 512
@@ -35,6 +34,12 @@
#define MIN_FETCH_DIRTYRATE_TIME_SEC 1
#define MAX_FETCH_DIRTYRATE_TIME_SEC 60
+/*
+ * Take 128 as minimum for sample dirty pages
+ */
+#define MIN_SAMPLE_PAGE_COUNT 128
+#define MAX_SAMPLE_PAGE_COUNT 4096
+
struct DirtyRateConfig {
uint64_t sample_pages_per_gigabytes; /* sample pages per GB */
int64_t sample_period_seconds; /* time duration between two sampling */
@@ -63,6 +68,7 @@ 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 */
+ uint64_t sample_pages; /* sample pages per GB */
};
void *get_dirtyrate_thread(void *arg);
diff --git a/qapi/migration.json b/qapi/migration.json
index 9bf0bc4..868a867 100644
--- a/qapi/migration.json
+++ b/qapi/migration.json
@@ -1741,6 +1741,9 @@
#
# @calc-time: time in units of second for sample dirty pages
#
+# @sample-pages: page count per GB for sample dirty pages
+# the default value is 512
+#
# Since: 5.2
#
##
@@ -1748,7 +1751,8 @@
'data': {'*dirty-rate': 'int64',
'status': 'DirtyRateStatus',
'start-time': 'int64',
- 'calc-time': 'int64'} }
+ 'calc-time': 'int64',
+ 'sample-pages': 'uint64'} }
##
# @calc-dirty-rate:
@@ -1757,13 +1761,16 @@
#
# @calc-time: time in units of second for sample dirty pages
#
+# @sample-pages: page count per GB for sample dirty pages
+# the default value is 512
+#
# Since: 5.2
#
# Example:
-# {"command": "calc-dirty-rate", "data": {"calc-time": 1} }
+# {"command": "calc-dirty-rate", "data": {"calc-time": 1, 'sample-pages':
512} }
#
##
-{ 'command': 'calc-dirty-rate', 'data': {'calc-time': 'int64'} }
+{ 'command': 'calc-dirty-rate', 'data': {'calc-time': 'int64',
'*sample-pages': 'int'} }
##
# @query-dirty-rate: