[PATCH v3 08/10] migration/dirtyrate: Implement get_sample_page_period() and block_sample_page_period()

[Chuan Zheng]

Implement get_sample_page_period() and set_sample_page_period() to
sleep specific time between sample actions.

Signed-off-by: Chuan Zheng <zhengchuan@huawei.com>
Signed-off-by: YanYing Zhuang <ann.zhuangyanying@huawei.com>
---
 migration/dirtyrate.c | 24 ++++++++++++++++++++++++
 migration/dirtyrate.h |  2 ++
 2 files changed, 26 insertions(+)

diff --git a/migration/dirtyrate.c b/migration/dirtyrate.c
index 6f30f67..4bbfcc3 100644
--- a/migration/dirtyrate.c
+++ b/migration/dirtyrate.c
@@ -28,6 +28,30 @@ CalculatingDirtyRateState CalculatingState = 
CAL_DIRTY_RATE_INIT;
 static unsigned long int qcrypto_hash_len = QCRYPTO_HASH_LEN;
 static struct DirtyRateStat dirty_stat;
 
+static int64_t set_sample_page_period(int64_t msec, int64_t initial_time)
+{
+    int64_t current_time;
+
+    current_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
+    if ((current_time - initial_time) >= msec) {
+        msec = current_time - initial_time;
+    } else {
+        g_usleep((msec + initial_time - current_time) * 1000);
+    }
+
+    return msec;
+}
+
+static int64_t get_sample_page_period(int64_t sec)
+{
+    if (sec <= MIN_FETCH_DIRTYRATE_TIME_SEC ||
+        sec > MAX_FETCH_DIRTYRATE_TIME_SEC) {
+        sec = DEFAULT_FETCH_DIRTYRATE_TIME_SEC;
+    }
+
+    return sec;
+}
+
 static int dirty_rate_set_state(int new_state)
 {
     int old_state = CalculatingState;
diff --git a/migration/dirtyrate.h b/migration/dirtyrate.h
index fce2e3b..86d8fa0 100644
--- a/migration/dirtyrate.h
+++ b/migration/dirtyrate.h
@@ -38,6 +38,8 @@
 
 /* Take 1s as default for calculation duration */
 #define DEFAULT_FETCH_DIRTYRATE_TIME_SEC          1
+#define MIN_FETCH_DIRTYRATE_TIME_SEC              0
+#define MAX_FETCH_DIRTYRATE_TIME_SEC              60
 
 struct DirtyRateConfig {
     uint64_t sample_pages_per_gigabytes; /* sample pages per GB */
-- 
1.8.3.1