[RFC PATCH 1/8] migration/dirtyrate: Add get_dirtyrate_thread() function

[Chuan Zheng <zhengchuan@huawei.com>]

From: Zheng Chuan <zhengchuan@huawei.com>

Add get_dirtyrate_thread() functions

Signed-off-by: Zheng Chuan <zhengchuan@huawei.com>
Signed-off-by: YanYing Zhang <ann.zhuangyanying@huawei.com>
---
 migration/dirtyrate.c | 63 +++++++++++++++++++++++++++++++++++++++++++++++++++
 migration/dirtyrate.h | 38 +++++++++++++++++++++++++++++++
 2 files changed, 101 insertions(+)
 create mode 100644 migration/dirtyrate.c
 create mode 100644 migration/dirtyrate.h

diff --git a/migration/dirtyrate.c b/migration/dirtyrate.c
new file mode 100644
index 0000000..fc652fb
--- /dev/null
+++ b/migration/dirtyrate.c
@@ -0,0 +1,63 @@
+/*
+ * Dirtyrate implement code
+ *
+ * Copyright (c) 2017-2020 HUAWEI TECHNOLOGIES CO.,LTD.
+ *
+ * Authors:
+ *  Chuan Zheng <zhengchuan@huawei.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ */
+
+#include "dirtyrate.h"
+
+static uint64_t sample_pages_per_gigabytes = DIRTYRATE_DEFAULT_SAMPLE_PAGES;
+static uint64_t dirty_rate; /* MB/s */
+CalculatingDirtyRateStage calculating_dirty_rate_stage = CAL_DIRTY_RATE_INIT;
+
+static bool calculate_dirtyrate(struct dirtyrate_config config,
+                        uint64_t *dirty_rate, int64_t time)
+{
+    /* todo */
+    return true;
+}
+
+static void set_dirty_rate(uint64_t drate)
+{
+    dirty_rate = drate;
+}
+
+/*
+ * There are multithread will write/read *calculating_dirty_rate_stage*,
+ * we can protect only one thread write/read it by libvirt api.
+ * So we don't add mutex_lock to protect it here, but we must calculate
+ * dirty_rate by libvirt api.
+ */
+static void set_dirty_rate_stage(CalculatingDirtyRateStage ratestage)
+{
+    calculating_dirty_rate_stage = ratestage;
+}
+
+void *get_dirtyrate_thread(void *arg)
+{
+    struct dirtyrate_config config = *(struct dirtyrate_config *)arg;
+    uint64_t dirty_rate;
+    uint64_t hash_dirty_rate;
+    bool query_succ;
+    int64_t msec = 0;
+ 
+    set_dirty_rate_stage(CAL_DIRTY_RATE_ING);
+
+    query_succ = calculate_dirtyrate(config, &hash_dirty_rate, msec);
+    if (!query_succ) {
+        dirty_rate = 0;
+    } else {
+        dirty_rate = hash_dirty_rate;
+    }
+
+    set_dirty_rate(dirty_rate);
+    set_dirty_rate_stage(CAL_DIRTY_RATE_END);
+
+    return NULL;
+}
diff --git a/migration/dirtyrate.h b/migration/dirtyrate.h
new file mode 100644
index 0000000..9a5c228
--- /dev/null
+++ b/migration/dirtyrate.h
@@ -0,0 +1,38 @@
+/*
+ *  Dirtyrate common functions
+ *
+ *  Copyright (c) 2020 HUAWEI TECHNOLOGIES CO., LTD.
+ *
+ *  Authors:
+ *  Chuan Zheng <zhengchuan@huawei.com>
+ *
+ *  This work is licensed under the terms of the GNU GPL, version 2 or later.
+ *  See the COPYING file in the top-level directory.
+ */
+
+#ifndef QEMU_MIGRATION_DIRTYRATE_H
+#define QEMU_MIGRATION_DIRTYRATE_H
+
+/* take 256 pages per GB for cal dirty rate */
+#define DIRTYRATE_DEFAULT_SAMPLE_PAGES    256
+
+struct dirtyrate_config {
+    uint64_t sample_pages_per_gigabytes;
+    int64_t sample_period_seconds;
+};
+
+/*
+ *  To record calculate dirty_rate status:
+ *  0: initial status, calculating thread is not be created here.
+ *  1: calculating thread is created.
+ *  2: calculating thread is end, we can get result.
+ */
+typedef enum {
+    CAL_DIRTY_RATE_INIT  = 0,
+    CAL_DIRTY_RATE_ING   = 1,
+    CAL_DIRTY_RATE_END   = 2,
+} CalculatingDirtyRateStage;
+
+void *get_dirtyrate_thread(void *arg);
+#endif
+
-- 
1.8.3.1