[PULL,13/38] migration: Non multifd migration don't care about multifd flushes

Commit Message

Juan Quintela Oct. 17, 2023, 8:29 a.m. UTC

RDMA was having trouble because
migrate_multifd_flush_after_each_section() can only be true or false,
but we don't want to send any flush when we are not in multifd
migration.

CC: Fabiano Rosas <[e-mail]
Fixes: 294e5a4034e81 ("multifd: Only flush once each full round of memory")

Reported-by: Li Zhijian <[e-mail]>
Reviewed-by: Li Zhijian <[e-mail]>
Reviewed-by: Peter Xu <[e-mail]>
Signed-off-by: Juan Quintela <[e-mail]>
Message-ID: <[e-mail]>
---
 migration/ram.c | 15 +++++++++------
 1 file changed, 9 insertions(+), 6 deletions(-)

Comments

Michael Tokarev Oct. 19, 2023, 11:47 a.m. UTC | #1

17.10.2023 11:29, Juan Quintela:
> RDMA was having trouble because
> migrate_multifd_flush_after_each_section() can only be true or false,
> but we don't want to send any flush when we are not in multifd
> migration.
> 
> CC: Fabiano Rosas <[e-mail]
> Fixes: 294e5a4034e81 ("multifd: Only flush once each full round of memory")

Is it worth to pick it up for stable-8.1?

/mjt

Juan Quintela Oct. 19, 2023, 12:03 p.m. UTC | #2

Michael Tokarev <[e-mail]> wrote:
> 17.10.2023 11:29, Juan Quintela:
>> RDMA was having trouble because
>> migrate_multifd_flush_after_each_section() can only be true or false,
>> but we don't want to send any flush when we are not in multifd
>> migration.
>> CC: Fabiano Rosas <[e-mail]
>> Fixes: 294e5a4034e81 ("multifd: Only flush once each full round of memory")
>
> Is it worth to pick it up for stable-8.1?

Yeap, please.

Later, Juan.

Patch

diff --git a/migration/ram.c b/migration/ram.c
index d3d9c8b65b..acb8f95f00 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -1395,7 +1395,8 @@  static int find_dirty_block(RAMState *rs, PageSearchStatus *pss)
         pss->page = 0;
         pss->block = QLIST_NEXT_RCU(pss->block, next);
         if (!pss->block) {
-            if (!migrate_multifd_flush_after_each_section()) {
+            if (migrate_multifd() &&
+                !migrate_multifd_flush_after_each_section()) {
                 QEMUFile *f = rs->pss[RAM_CHANNEL_PRECOPY].pss_channel;
                 int ret = multifd_send_sync_main(f);
                 if (ret < 0) {
@@ -3072,7 +3073,7 @@  static int ram_save_setup(QEMUFile *f, void *opaque)
         return ret;
     }
 
-    if (!migrate_multifd_flush_after_each_section()) {
+    if (migrate_multifd() && !migrate_multifd_flush_after_each_section()) {
         qemu_put_be64(f, RAM_SAVE_FLAG_MULTIFD_FLUSH);
     }
 
@@ -3184,7 +3185,7 @@  static int ram_save_iterate(QEMUFile *f, void *opaque)
 out:
     if (ret >= 0
         && migration_is_setup_or_active(migrate_get_current()->state)) {
-        if (migrate_multifd_flush_after_each_section()) {
+        if (migrate_multifd() && migrate_multifd_flush_after_each_section()) {
             ret = multifd_send_sync_main(rs->pss[RAM_CHANNEL_PRECOPY].pss_channel);
             if (ret < 0) {
                 return ret;
@@ -3261,7 +3262,7 @@  static int ram_save_complete(QEMUFile *f, void *opaque)
         return ret;
     }
 
-    if (!migrate_multifd_flush_after_each_section()) {
+    if (migrate_multifd() && !migrate_multifd_flush_after_each_section()) {
         qemu_put_be64(f, RAM_SAVE_FLAG_MULTIFD_FLUSH);
     }
     qemu_put_be64(f, RAM_SAVE_FLAG_EOS);
@@ -3768,7 +3769,8 @@  int ram_load_postcopy(QEMUFile *f, int channel)
             break;
         case RAM_SAVE_FLAG_EOS:
             /* normal exit */
-            if (migrate_multifd_flush_after_each_section()) {
+            if (migrate_multifd() &&
+                migrate_multifd_flush_after_each_section()) {
                 multifd_recv_sync_main();
             }
             break;
@@ -4046,7 +4048,8 @@  static int ram_load_precopy(QEMUFile *f)
             break;
         case RAM_SAVE_FLAG_EOS:
             /* normal exit */
-            if (migrate_multifd_flush_after_each_section()) {
+            if (migrate_multifd() &&
+                migrate_multifd_flush_after_each_section()) {
                 multifd_recv_sync_main();
             }
             break;