1 files changed, 27 insertions, 11 deletions

diff --git a/migration/ram.c b/migration/ram.c
index 42fb8ac6d6..f3fe6c7aae 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -265,6 +265,7 @@ typedef struct CompressParam CompressParam;
 
 struct DecompressParam {
     bool start;
+    bool done;
     QemuMutex mutex;
     QemuCond cond;
     void *des;
@@ -289,6 +290,8 @@ static bool quit_comp_thread;
 static bool quit_decomp_thread;
 static DecompressParam *decomp_param;
 static QemuThread *decompress_threads;
+static QemuMutex decomp_done_lock;
+static QemuCond decomp_done_cond;
 
 static int do_compress_ram_page(CompressParam *param);
 
@@ -834,6 +837,7 @@ static inline void start_compression(CompressParam *param)
 
 static inline void start_decompression(DecompressParam *param)
 {
+    param->done = false;
     qemu_mutex_lock(&param->mutex);
     param->start = true;
     qemu_cond_signal(&param->cond);
@@ -2196,19 +2200,24 @@ static void *do_data_decompress(void *opaque)
         qemu_mutex_lock(&param->mutex);
         while (!param->start && !quit_decomp_thread) {
             qemu_cond_wait(&param->cond, &param->mutex);
+        }
+        if (!quit_decomp_thread) {
             pagesize = TARGET_PAGE_SIZE;
-            if (!quit_decomp_thread) {
-                /* uncompress() will return failed in some case, especially
-                 * when the page is dirted when doing the compression, it's
-                 * not a problem because the dirty page will be retransferred
-                 * and uncompress() won't break the data in other pages.
-                 */
-                uncompress((Bytef *)param->des, &pagesize,
-                           (const Bytef *)param->compbuf, param->len);
-            }
-            param->start = false;
+            /* uncompress() will return failed in some case, especially
+             * when the page is dirted when doing the compression, it's
+             * not a problem because the dirty page will be retransferred
+             * and uncompress() won't break the data in other pages.
+             */
+            uncompress((Bytef *)param->des, &pagesize,
+                       (const Bytef *)param->compbuf, param->len);
         }
+        param->start = false;
         qemu_mutex_unlock(&param->mutex);
+
+        qemu_mutex_lock(&decomp_done_lock);
+        param->done = true;
+        qemu_cond_signal(&decomp_done_cond);
+        qemu_mutex_unlock(&decomp_done_lock);
     }
 
     return NULL;
@@ -2222,10 +2231,13 @@ void migrate_decompress_threads_create(void)
     decompress_threads = g_new0(QemuThread, thread_count);
     decomp_param = g_new0(DecompressParam, thread_count);
     quit_decomp_thread = false;
+    qemu_mutex_init(&decomp_done_lock);
+    qemu_cond_init(&decomp_done_cond);
     for (i = 0; i < thread_count; i++) {
         qemu_mutex_init(&decomp_param[i].mutex);
         qemu_cond_init(&decomp_param[i].cond);
         decomp_param[i].compbuf = g_malloc0(compressBound(TARGET_PAGE_SIZE));
+        decomp_param[i].done = true;
         qemu_thread_create(decompress_threads + i, "decompress",
                            do_data_decompress, decomp_param + i,
                            QEMU_THREAD_JOINABLE);
@@ -2261,9 +2273,10 @@ static void decompress_data_with_multi_threads(QEMUFile *f,
     int idx, thread_count;
 
     thread_count = migrate_decompress_threads();
+    qemu_mutex_lock(&decomp_done_lock);
     while (true) {
         for (idx = 0; idx < thread_count; idx++) {
-            if (!decomp_param[idx].start) {
+            if (decomp_param[idx].done) {
                 qemu_get_buffer(f, decomp_param[idx].compbuf, len);
                 decomp_param[idx].des = host;
                 decomp_param[idx].len = len;
@@ -2273,8 +2286,11 @@ static void decompress_data_with_multi_threads(QEMUFile *f,
         }
         if (idx < thread_count) {
             break;
+        } else {
+            qemu_cond_wait(&decomp_done_cond, &decomp_done_lock);
         }
     }
+    qemu_mutex_unlock(&decomp_done_lock);
 }
 
 /*