From: Wei Yang <richardw.y...@linux.intel.com>
After cleanup, it would be clear to audience there are two cases
ram_load:
* precopy
* postcopy
And it is not necessary to check postcopy_running on each iteration for
precopy.
Signed-off-by: Wei Yang <richardw.y...@linux.intel.com>
Reviewed-by: Dr. David Alan Gilbert <dgilb...@redhat.com>
Message-Id: <20190725002023.2335-3-richardw.y...@linux.intel.com>
Signed-off-by: Dr. David Alan Gilbert <dgilb...@redhat.com>
---
migration/ram.c | 73 +++++++++++++++++++++++++++++++------------------
1 file changed, 46 insertions(+), 27 deletions(-)
diff --git a/migration/ram.c b/migration/ram.c
index 6a75aedc91..a44e9c0abc 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -4318,40 +4318,26 @@ static void colo_flush_ram_cache(void)
trace_colo_flush_ram_cache_end();
}
-static int ram_load(QEMUFile *f, void *opaque, int version_id)
+/**
+ * ram_load_precopy: load pages in precopy case
+ *
+ * Returns 0 for success or -errno in case of error
+ *
+ * Called in precopy mode by ram_load().
+ * rcu_read_lock is taken prior to this being called.
+ *
+ * @f: QEMUFile where to send the data
+ */
+static int ram_load_precopy(QEMUFile *f)
{
- int flags = 0, ret = 0, invalid_flags = 0;
- static uint64_t seq_iter;
- int len = 0;
- /*
- * If system is running in postcopy mode, page inserts to host memory must
- * be atomic
- */
- bool postcopy_running = postcopy_is_running();
+ int flags = 0, ret = 0, invalid_flags = 0, len = 0;
/* ADVISE is earlier, it shows the source has the postcopy capability on */
bool postcopy_advised = postcopy_is_advised();
-
- seq_iter++;
-
- if (version_id != 4) {
- return -EINVAL;
- }
-
if (!migrate_use_compression()) {
invalid_flags |= RAM_SAVE_FLAG_COMPRESS_PAGE;
}
- /* This RCU critical section can be very long running.
- * When RCU reclaims in the code start to become numerous,
- * it will be necessary to reduce the granularity of this
- * critical section.
- */
- rcu_read_lock();
-
- if (postcopy_running) {
- ret = ram_load_postcopy(f);
- }
- while (!postcopy_running && !ret && !(flags & RAM_SAVE_FLAG_EOS)) {
+ while (!ret && !(flags & RAM_SAVE_FLAG_EOS)) {
ram_addr_t addr, total_ram_bytes;
void *host = NULL;
uint8_t ch;
@@ -4502,6 +4488,39 @@ static int ram_load(QEMUFile *f, void *opaque, int
version_id)
}
}
+ return ret;
+}
+
+static int ram_load(QEMUFile *f, void *opaque, int version_id)
+{
+ int ret = 0;
+ static uint64_t seq_iter;
+ /*
+ * If system is running in postcopy mode, page inserts to host memory must
+ * be atomic
+ */
+ bool postcopy_running = postcopy_is_running();
+
+ seq_iter++;
+
+ if (version_id != 4) {
+ return -EINVAL;
+ }
+
+ /*
+ * This RCU critical section can be very long running.
+ * When RCU reclaims in the code start to become numerous,
+ * it will be necessary to reduce the granularity of this
+ * critical section.
+ */
+ rcu_read_lock();
+
+ if (postcopy_running) {
+ ret = ram_load_postcopy(f);
+ } else {
+ ret = ram_load_precopy(f);
+ }
+
ret |= wait_for_decompress_done();
rcu_read_unlock();
trace_ram_load_complete(ret, seq_iter);
--
2.21.0
