* Peter Xu (pet...@redhat.com) wrote:
> The preempt mode requires the capability to assign channel for each of the
> page, while the compression logic will currently assign pages to different
> compress thread/local-channel so potentially they're incompatible.
>
> Signed-off-by: Peter Xu <pet...@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilb...@redhat.com>
> ---
> migration/migration.c | 11 +++++++++++
> 1 file changed, 11 insertions(+)
>
> diff --git a/migration/migration.c b/migration/migration.c
> index fb4066dfb4..07c74a79a2 100644
> --- a/migration/migration.c
> +++ b/migration/migration.c
> @@ -1341,6 +1341,17 @@ static bool migrate_caps_check(bool *cap_list,
> error_setg(errp, "Postcopy preempt requires postcopy-ram");
> return false;
> }
> +
> + /*
> + * Preempt mode requires urgent pages to be sent in separate
> + * channel, OTOH compression logic will disorder all pages into
> + * different compression channels, which is not compatible with the
> + * preempt assumptions on channel assignments.
> + */
> + if (cap_list[MIGRATION_CAPABILITY_COMPRESS]) {
> + error_setg(errp, "Postcopy preempt not compatible with
> compress");
> + return false;
> + }
> }
>
> return true;
> --
> 2.32.0
>
--
Dr. David Alan Gilbert / dgilb...@redhat.com / Manchester, UK
