Commit: fc6705229cbca807f2bab9a8acf22b0ab249e55c - qemu (git)

Commit MetaInfo

• Revision: fc6705229cbca807f2bab9a8acf22b0ab249e55c (tree)
• Time: 2022-01-28 23:38:23
• Author: Juan Quintela <quintela@redh...>
• Commiter: Juan Quintela

Log Message

multifd: Use proper maximum compression values

It happens that there are functions to calculate the worst possible
compression size for a packet. Use them.

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

Change Summary

• modified: migration/multifd-zlib.c
• modified: migration/multifd-zstd.c

Incremental Difference

--- a/migration/multifd-zlib.c
+++ b/migration/multifd-zlib.c
@@ -54,8 +54,8 @@ static int zlib_send_setup(MultiFDSendParams *p, Error **errp)
         error_setg(errp, "multifd %u: deflate init failed", p->id);
         return -1;
     }
-    /* To be safe, we reserve twice the size of the packet */
-    z->zbuff_len = MULTIFD_PACKET_SIZE * 2;
+    /* This is the maxium size of the compressed buffer */
+    z->zbuff_len = compressBound(MULTIFD_PACKET_SIZE);
     z->zbuff = g_try_malloc(z->zbuff_len);
     if (!z->zbuff) {
         deflateEnd(&z->zs);

--- a/migration/multifd-zstd.c
+++ b/migration/multifd-zstd.c
@@ -67,8 +67,8 @@ static int zstd_send_setup(MultiFDSendParams *p, Error **errp)
                    p->id, ZSTD_getErrorName(res));
         return -1;
     }
-    /* To be safe, we reserve twice the size of the packet */
-    z->zbuff_len = MULTIFD_PACKET_SIZE * 2;
+    /* This is the maxium size of the compressed buffer */
+    z->zbuff_len = ZSTD_compressBound(MULTIFD_PACKET_SIZE);
     z->zbuff = g_try_malloc(z->zbuff_len);
     if (!z->zbuff) {
         ZSTD_freeCStream(z->zcs);