Re: [PATCH] Revert "tests/migration: Reduce autoconverge initial bandwidth"

[Dr. David Alan Gilbert]

* Michael S. Tsirkin (mst@redhat.com) wrote:
> This reverts commit 6d1da867e65f ("tests/migration: Reduce autoconverge 
> initial bandwidth")
> since that change makes unit tests much slower for all developers, while it's 
> not
> a robust way to fix migration tests. Migration tests need to find
> a more robust way to discover a reasonable bandwidth without slowing
> things down for everyone.
> 
> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

Yeh, I'd hoped something else could provide another way but I hadn't
realised how this worked;  You don't hit auto-converge until you've done
two passes, since we're running ~100MByte of dirty memory, that means
it wont hit the autoconverge stage until
2x100MByte/1MByte bandwidth=200 seconds

I'm actually measuring 130 seconds, which seems sane to me, since
there's a lot of overlap; so yeh we need to find a different way to set
this up.


Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>


> ---
>  tests/qtest/migration-test.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/tests/qtest/migration-test.c b/tests/qtest/migration-test.c
> index dc3490c9fa..21ea5ba1d2 100644
> --- a/tests/qtest/migration-test.c
> +++ b/tests/qtest/migration-test.c
> @@ -1211,7 +1211,7 @@ static void test_migrate_auto_converge(void)
>       * without throttling.
>       */
>      migrate_set_parameter_int(from, "downtime-limit", 1);
> -    migrate_set_parameter_int(from, "max-bandwidth", 1000000); /* ~1Mb/s */
> +    migrate_set_parameter_int(from, "max-bandwidth", 100000000); /* ~100Mb/s 
> */
>  
>      /* To check remaining size after precopy */
>      migrate_set_capability(from, "pause-before-switchover", true);
> -- 
> MST
> 
--
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK