ram.c: Dont change param->block in the compress thread

Instead introduce a extra parameter to trigger the compress thread.
Now, when the compress thread is done, we know what RAMBlock and
offset it did compress.

This will be used in the next commits to move save_page_header()
out of compress code.

Signed-off-by: Lukas Straub <lukasstraub2@web.de>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>

diff --git a/migration/ram.c b/migration/ram.c
index 7bc05fc034283a2460d806f65ab3cac3028ab893..b552a9e538e50b2f0c7556d50513667f1255eb7f 100644 (file)
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -492,6 +492,7 @@ typedef enum CompressResult CompressResult;
 struct CompressParam {
     bool done;
     bool quit;
+    bool trigger;
     CompressResult result;
     QEMUFile *file;
     QemuMutex mutex;
@@ -565,10 +566,10 @@ static void *do_data_compress(void *opaque)
 
     qemu_mutex_lock(&param->mutex);
     while (!param->quit) {
-        if (param->block) {
+        if (param->trigger) {
             block = param->block;
             offset = param->offset;
-            param->block = NULL;
+            param->trigger = false;
             qemu_mutex_unlock(&param->mutex);
 
             result = do_compress_ram_page(param->file, &param->stream,
@@ -1545,6 +1546,7 @@ static inline void set_compress_params(CompressParam *param, RAMBlock *block,
 {
     param->block = block;
     param->offset = offset;
+    param->trigger = true;
 }
 
 static int compress_page_with_multi_thread(RAMBlock *block, ram_addr_t offset)