David Vrabel <david.vrabel@xxxxxxxxxx> writes: > On 22/12/15 16:32, Vitaly Kuznetsov wrote: >> @@ -1292,6 +1304,11 @@ int __ref add_memory_resource(int nid, struct resource *res) >> /* create new memmap entry */ >> firmware_map_add_hotplug(start, start + size, "System RAM"); >> >> + /* online pages if requested */ >> + if (online) >> + online_pages(start >> PAGE_SHIFT, size >> PAGE_SHIFT, >> + MMOP_ONLINE_KEEP); > > This will cause the Xen balloon driver to deadlock because it calls > add_memory_resource() with the balloon_mutex locked and the online page > callback also locks the balloon_mutex. Currently xen ballon driver always calls add_memory_resource() with online=false so this won't happen. -- Vitaly -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>