Patchwork [RFC,5/9] migration: check for dup pages only in bulk stage

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Submitter Peter Lieven
Date March 12, 2013, 3:51 p.m.
Message ID <513F4EEC.9050903@dlhnet.de>
Download mbox | patch
Permalink /patch/227065/
State New
Headers show

Comments

Peter Lieven - March 12, 2013, 3:51 p.m.
pages are dup (most likely zero) from the very beginning.
unless there is an application running inside the VM
zeroing out large areas of memory its wasted time
for checking for dup pages after the bulk stage.

Signed-off-by: Peter Lieven <pl@kamp.de>
---
  arch_init.c |    2 +-
  1 file changed, 1 insertion(+), 1 deletion(-)

Patch

diff --git a/arch_init.c b/arch_init.c
index d48b914..3d09327 100644
--- a/arch_init.c
+++ b/arch_init.c
@@ -445,7 +445,7 @@  static int ram_save_block(QEMUFile *f, bool last_stage)

              /* In doubt sent page as normal */
              bytes_sent = -1;
-            if (is_dup_page(p)) {
+            if (ram_bulk_stage && is_dup_page(p)) {
                  acct_info.dup_pages++;
                  bytes_sent = save_block_hdr(f, block, offset, cont,
                                              RAM_SAVE_FLAG_COMPRESS);