Streaming and the commit block job only want to apply throttling when
they actually copied data instead of skipping it, so they made the
calculation of delay_ns conditional. However, delay_ns isn't reset when
skipping some sectors, so instead of not waiting, the old delay is
applied again.

Properly reset delay_ns where needed.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 block/commit.c | 2 ++
 block/stream.c | 2 ++
 2 files changed, 4 insertions(+)

diff --git a/block/commit.c b/block/commit.c
index ab4fa3c3cf..1432baeef4 100644
--- a/block/commit.c
+++ b/block/commit.c
@@ -202,6 +202,8 @@ static void coroutine_fn commit_run(void *opaque)
 
         if (copy && s->common.speed) {
             delay_ns = ratelimit_calculate_delay(&s->limit, n);
+        } else {
+            delay_ns = 0;
         }
     }
 
diff --git a/block/stream.c b/block/stream.c
index f3b53f49e2..1a85708fcf 100644
--- a/block/stream.c
+++ b/block/stream.c
@@ -188,6 +188,8 @@ static void coroutine_fn stream_run(void *opaque)
         s->common.offset += n;
         if (copy && s->common.speed) {
             delay_ns = ratelimit_calculate_delay(&s->limit, n);
+        } else {
+            delay_ns = 0;
         }
     }
 
-- 
2.13.6

On 04/10/2018 03:58 AM, Kevin Wolf wrote:
> Streaming and the commit block job only want to apply throttling when
> they actually copied data instead of skipping it, so they made the
> calculation of delay_ns conditional. However, delay_ns isn't reset when
> skipping some sectors, so instead of not waiting, the old delay is
> applied again.
> 
> Properly reset delay_ns where needed.
> 
> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
> ---
>  block/commit.c | 2 ++
>  block/stream.c | 2 ++
>  2 files changed, 4 insertions(+)
> 
Reviewed-by: Eric Blake <eblake@redhat.com>

-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3266
Virtualization:  qemu.org | libvirt.org

On Tue, Apr 10, 2018 at 10:58:09AM +0200, Kevin Wolf wrote:
> Streaming and the commit block job only want to apply throttling when
> they actually copied data instead of skipping it, so they made the
> calculation of delay_ns conditional. However, delay_ns isn't reset when
> skipping some sectors, so instead of not waiting, the old delay is
> applied again.
> 
> Properly reset delay_ns where needed.
> 
> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
> ---
>  block/commit.c | 2 ++
>  block/stream.c | 2 ++
>  2 files changed, 4 insertions(+)

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>