From: Felipe Franciosi <felipe@nutanix.com>
Date: Wed, 24 May 2017 16:10:03 +0000 (+0100)
Subject: migration: use dirty_rate_high_cnt more aggressively
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=b4a3c64b16856a018869bfd4a9ed3b2a74554541;p=qemu.git

migration: use dirty_rate_high_cnt more aggressively

The commit message from 070afca25 suggests that dirty_rate_high_cnt
should be used more aggressively to start throttling after two
iterations instead of four. The code, however, only changes the auto
convergence behaviour to throttle after three iterations. This makes the
behaviour more aggressive by kicking off throttling after two iterations
as originally intended.

Signed-off-by: Felipe Franciosi <felipe@nutanix.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
---

diff --git a/migration/ram.c b/migration/ram.c
index 1a3d9e6d87..26e03a5dfa 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -708,7 +708,7 @@ static void migration_bitmap_sync(RAMState *rs)
 
             if ((rs->num_dirty_pages_period * TARGET_PAGE_SIZE >
                    (bytes_xfer_now - rs->bytes_xfer_prev) / 2) &&
-                (rs->dirty_rate_high_cnt++ >= 2)) {
+                (++rs->dirty_rate_high_cnt >= 2)) {
                     trace_migration_throttle();
                     rs->dirty_rate_high_cnt = 0;
                     mig_throttle_guest_down();