Re: [Qemu-devel] [PATCH 1/6] tests: Add basic migration precopy test

[Peter Xu <peterx@redhat.com>]

On Wed, Oct 04, 2017 at 12:39:28PM +0200, Juan Quintela wrote:

[...]

(having some unit tests for migration is really good...)

> +static void test_precopy(const char *uri)
> +{
> +    QTestState *from, *to;
> +
> +    test_migrate_start(&from, &to, uri);
> +
> +    /* We want to pick a speed slow enough that the test completes
> +     * quickly, but that it doesn't complete precopy even on a slow
> +     * machine, so also set the downtime.
> +     */
> +    /* 100 ms */
> +    migrate_set_parameter(from, "downtime-limit", "100");
> +    /* 1MB/s slow*/

This is 100MB/s?

> +    migrate_set_parameter(from, "max-bandwidth", "100000000");
> +
> +    /* Wait for the first serial output from the source */
> +    wait_for_serial("src_serial");
> +
> +    migrate(from, uri);
> +
> +    wait_for_migration_pass(from);
> +
> +    /* 1GB/s now it should converge */
> +    migrate_set_parameter(from, "max-bandwidth", "1000000000");

Curious: would it possible that 1GB/s won't suffice in some cases?
Is there any reason behind this 1GB/s value?

(I agree with Thomas that it would be good to work upon the existing
 postcopy-test.c file, at least easier to review :)

Thanks,

-- 
Peter Xu