Message ID | 20221004182430.97638-4-peterx@redhat.com (mailing list archive) |
---|---|
State | New, archived |
Headers | show |
Series | migration: Bug fixes (prepare for preempt-full) | expand |
Peter Xu <peterx@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. > > Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com> > Signed-off-by: Peter Xu <peterx@redhat.com> Reviewed-by: Juan Quintela <quintela@redhat.com>
diff --git a/migration/migration.c b/migration/migration.c index bb8bbddfe4..844bca1ff6 100644 --- a/migration/migration.c +++ b/migration/migration.c @@ -1336,6 +1336,17 @@ 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;