From 86be843cee1157f605820fc02a8cad8a00fe09e9 Mon Sep 17 00:00:00 2001
From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Date: Fri, 17 Jun 2016 14:39:22 +0200
Subject: [PATCH 01/33] Postcopy: Avoid 0 length discards
RH-Author: Dr. David Alan Gilbert <dgilbert@redhat.com>
Message-id: <1466174367-11047-2-git-send-email-dgilbert@redhat.com>
Patchwork-id: 70659
O-Subject: [RHEL-7.3 qemu-kvm-rhev PATCH 1/6] Postcopy: Avoid 0 length discards
Bugzilla: 1347256
RH-Acked-by: Juan Quintela <quintela@redhat.com>
RH-Acked-by: John Snow <jsnow@redhat.com>
RH-Acked-by: Amit Shah <amit.shah@redhat.com>
From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
The discard code in migration/ram.c would send request for
zero length discards in the case where no discards were needed.
It doesn't appear to have had any bad effect.
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Denis V. Lunev <den@openvz.org>
Message-id: 1465816605-29488-2-git-send-email-dgilbert@redhat.com
Message-Id: <1465816605-29488-2-git-send-email-dgilbert@redhat.com>
Signed-off-by: Amit Shah <amit.shah@redhat.com>
(cherry picked from commit d688c62d0928c46437b6b95848922398674538c8)
Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>
---
migration/ram.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/migration/ram.c b/migration/ram.c
index 3f05738..e96c2af 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -1557,7 +1557,9 @@ static int postcopy_send_discard_bm_ram(MigrationState *ms,
} else {
discard_length = zero - one;
}
- postcopy_discard_send_range(ms, pds, one, discard_length);
+ if (discard_length) {
+ postcopy_discard_send_range(ms, pds, one, discard_length);
+ }
current = one + discard_length;
} else {
current = one;
--
1.8.3.1