Subject: [merged] mm-memory_hotplugc-move-register_memory_resource-out-of-the-lock_memory_hotplug.patch removed from -mm tree To: nzimmer@xxxxxxx,hedi@xxxxxxx,isimatu.yasuaki@xxxxxxxxxxxxxx,kamezawa.hiroyu@xxxxxxxxxxxxxx,rafael.j.wysocki@xxxxxxxxx,tangchen@xxxxxxxxxxxxxx,travis@xxxxxxx,wency@xxxxxxxxxxxxxx,mm-commits@xxxxxxxxxxxxxxx From: akpm@xxxxxxxxxxxxxxxxxxxx Date: Fri, 24 Jan 2014 10:59:23 -0800 The patch titled Subject: mm/memory_hotplug.c: move register_memory_resource out of the lock_memory_hotplug has been removed from the -mm tree. Its filename was mm-memory_hotplugc-move-register_memory_resource-out-of-the-lock_memory_hotplug.patch This patch was dropped because it was merged into mainline or a subsystem tree ------------------------------------------------------ From: Nathan Zimmer <nzimmer@xxxxxxx> Subject: mm/memory_hotplug.c: move register_memory_resource out of the lock_memory_hotplug We don't need to do register_memory_resource() under lock_memory_hotplug() 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: Tang Chen <tangchen@xxxxxxxxxxxxxx> Cc: Wen Congyang <wency@xxxxxxxxxxxxxx> Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx> Reviewed-by: Yasuaki Ishimatsu <isimatu.yasuaki@xxxxxxxxxxxxxx> Cc: "Rafael J. Wysocki" <rafael.j.wysocki@xxxxxxxxx> Cc: Hedi <hedi@xxxxxxx> Cc: Mike Travis <travis@xxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/memory_hotplug.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff -puN mm/memory_hotplug.c~mm-memory_hotplugc-move-register_memory_resource-out-of-the-lock_memory_hotplug mm/memory_hotplug.c --- a/mm/memory_hotplug.c~mm-memory_hotplugc-move-register_memory_resource-out-of-the-lock_memory_hotplug +++ a/mm/memory_hotplug.c @@ -1107,17 +1107,18 @@ int __ref add_memory(int nid, u64 start, if (ret) return 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); _ Patches currently in -mm which might be from nzimmer@xxxxxxx are origin.patch -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html