We don't need to do register_memory_resource() since it has its own lock and doesn't make any callbacks.
Also register_memory_resource return NULL on failure so we don't have anything to cleanup at this point. The reason for this rfc is I was doing some experiments with hotplugging of memory on some of our larger systems. While it seems to work, it can be quite slow. With some preliminary digging I found that lock_memory_hotplug is clearly ripe for breakup. It could be broken up per nid or something but it also covers the online_page_callback. The online_page_callback shouldn't be very hard to break out. Also there is the issue of various structures(wmarks come to mind) that are only updated under the lock_memory_hotplug that would need to be dealt with. cc: Andrew Morton <[email protected]> cc: Tang Chen <[email protected]> cc: Wen Congyang <[email protected]> cc: Kamezawa Hiroyuki <[email protected]> cc: Yasuaki Ishimatsu <[email protected]> cc: "Rafael J. Wysocki" <[email protected]> cc: Hedi <[email protected]> cc: Mike Travis <[email protected]> cc: [email protected] cc: [email protected] --- mm/memory_hotplug.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index 1ad92b4..62a0cd1 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -1097,17 +1097,18 @@ int __ref add_memory(int nid, u64 start, u64 size) struct resource *res; int ret; - lock_memory_hotplug(); - res = register_memory_resource(start, size); ret = -EEXIST; if (!res) - goto out; + return ret; { /* Stupid hack to suppress address-never-null warning */ void *p = NODE_DATA(nid); new_pgdat = !p; } + + lock_memory_hotplug(); + new_node = !node_online(nid); if (new_node) { pgdat = hotadd_new_pgdat(nid, start); -- 1.8.2.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
