Commit: f30c2e5ba81b8d388b7beeae84e6db5ea8220924 - qemu (git)

Commit MetaInfo

• Revision: f30c2e5ba81b8d388b7beeae84e6db5ea8220924 (tree)
• Time: 2022-01-28 23:38:23
• Author: Peter Xu <peterx@redh...>
• Commiter: Juan Quintela

Log Message

migration: Do chunk page in postcopy_each_ram_send_discard()

Right now we loop ramblocks for twice, the 1st time chunk the dirty bits with
huge page information; the 2nd time we send the discard ranges. That's not
necessary - we can do them in a single loop.

Signed-off-by: Peter Xu <[e-mail]>
Reviewed-by: Dr. David Alan Gilbert <[e-mail]>
Reviewed-by: Juan Quintela <[e-mail]>
Signed-off-by: Juan Quintela <[e-mail]>

Change Summary

• modified: migration/ram.c

Incremental Difference

--- a/migration/ram.c
+++ b/migration/ram.c
@@ -2454,6 +2454,8 @@ static int postcopy_send_discard_bm_ram(MigrationState *ms, RAMBlock *block)
     return 0;
 }
 
+static void postcopy_chunk_hostpages_pass(MigrationState *ms, RAMBlock *block);
+
 /**
  * postcopy_each_ram_send_discard: discard all RAMBlocks
  *
@@ -2476,6 +2478,14 @@ static int postcopy_each_ram_send_discard(MigrationState *ms)
         postcopy_discard_send_init(ms, block->idstr);
 
         /*
+         * Deal with TPS != HPS and huge pages.  It discard any partially sent
+         * host-page size chunks, mark any partially dirty host-page size
+         * chunks as all dirty.  In this case the host-page is the host-page
+         * for the particular RAMBlock, i.e. it might be a huge page.
+         */
+        postcopy_chunk_hostpages_pass(ms, block);
+
+        /*
          * Postcopy sends chunks of bitmap over the wire, but it
          * just needs indexes at this point, avoids it having
          * target page specific code.
@@ -2575,7 +2585,6 @@ static void postcopy_chunk_hostpages_pass(MigrationState *ms, RAMBlock *block)
 int ram_postcopy_send_discard_bitmap(MigrationState *ms)
 {
     RAMState *rs = ram_state;
-    RAMBlock *block;
 
     RCU_READ_LOCK_GUARD();
 
@@ -2587,15 +2596,6 @@ int ram_postcopy_send_discard_bitmap(MigrationState *ms)
     rs->last_sent_block = NULL;
     rs->last_page = 0;
 
-    RAMBLOCK_FOREACH_NOT_IGNORED(block) {
-        /*
-         * Deal with TPS != HPS and huge pages.  It discard any partially sent
-         * host-page size chunks, mark any partially dirty host-page size
-         * chunks as all dirty.  In this case the host-page is the host-page
-         * for the particular RAMBlock, i.e. it might be a huge page.
-         */
-        postcopy_chunk_hostpages_pass(ms, block);
-    }
     trace_ram_postcopy_send_discard_bitmap();
 
     return postcopy_each_ram_send_discard(ms);