From 45d723c48255328fbd5128c4c70c91103e420590 Mon Sep 17 00:00:00 2001

From: Michael Roth <mdroth@linux.vnet.ibm.com>

Date: Thu, 16 May 2013 16:25:44 -0500

Subject: [PATCH] Revert "migration: don't account sleep time for calculating

 bandwidth"

This reverts commit 7161082c8d8cf167c508976887a0a63f4db92b51.

Reverting this patch fixes a divide-by-zero error in qemu that can be

fairly reliably triggered by doing block migration. In this case, the

configuration/error was:

source: temp/x86_64-softmmu/qemu-system-x86_64 -enable-kvm -L temp-bios

-M pc-i440fx-1.4 -m 512M -kernel boot/vmlinuz-x86_64 -initrd

boot/test-initramfs-x86_64.img.gz -vga std -append seed=1234 -drive

file=disk1.img,if=virtio -drive file=disk2.img,if=virtio -device

virtio-net-pci,netdev=net0 -netdev user,id=net0 -monitor

unix:/tmp/vm-hmp.sock,server,nowait -qmp

unix:/tmp/vm-qmp.sock,server,nowait -vnc :100

16837 Floating point exception(core dumped)

target: temp/x86_64-softmmu/qemu-system-x86_64 -enable-kvm -L temp-bios

-M pc-i440fx-1.4 -m 512M -kernel boot/vmlinuz-x86_64 -initrd

boot/test-initramfs-x86_64.img.gz -vga std -append seed=1234 -drive

file=target_disk1.img,if=virtio -drive file=target_disk2.img,if=virtio

-device virtio-net-pci,netdev=net0 -netdev user,id=net0 -incoming

unix:/tmp/migrate.sock -monitor

unix:/tmp/vm-hmp-incoming.sock,server,nowait -qmp

unix:/tmp/vm-qmp-incoming.sock,server,nowait -vnc :101

Receiving block device images

20 %

21 %

load of migration failed

This revert potentially re-introduces a bug that was present in 1.4,

but fixes a prevalent issue with block migration so we should revert

it for now and take an updated patch later.

Conflicts:

	migration.c

* fixed up to remove logic introduced in 7161082c while leaving

  changes in HEAD intact

Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>

Message-id: 1368739544-31021-1-git-send-email-mdroth@linux.vnet.ibm.com

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

(cherry picked from commit 77417f10701d330c7005b0f0a2c0cef9e05d430d)

---

 migration.c | 5 +----

 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/migration.c b/migration.c

index 0aff06d..cca6df6 100644

--- a/migration.c

+++ b/migration.c

@@ -497,7 +497,6 @@ static void *migration_thread(void *opaque)

 {

     MigrationState *s = opaque;

     int64_t initial_time = qemu_get_clock_ms(rt_clock);

-    int64_t sleep_time = 0;

     int64_t initial_bytes = 0;

     int64_t max_size = 0;

     int64_t start_time = initial_time;

@@ -540,7 +539,7 @@ static void *migration_thread(void *opaque)

         current_time = qemu_get_clock_ms(rt_clock);

         if (current_time >= initial_time + BUFFER_DELAY) {

             uint64_t transferred_bytes = qemu_ftell(s->file) - initial_bytes;

-            uint64_t time_spent = current_time - initial_time - sleep_time;

+            uint64_t time_spent = current_time - initial_time;

             double bandwidth = transferred_bytes / time_spent;

             max_size = bandwidth * migrate_max_downtime() / 1000000;

@@ -554,14 +553,12 @@ static void *migration_thread(void *opaque)

             }

             qemu_file_reset_rate_limit(s->file);

-            sleep_time = 0;

             initial_time = current_time;

             initial_bytes = qemu_ftell(s->file);

         }

         if (qemu_file_rate_limit(s->file)) {

             /* usleep expects microseconds */

             g_usleep((initial_time + BUFFER_DELAY - current_time)*1000);

-            sleep_time += qemu_get_clock_ms(rt_clock) - current_time;

         }

     }