(2014/01/15 3:24), Nathan Zimmer wrote: > 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] > > > ---
The patch seems good to me. Reviewed-by: Yasuaki Ishimatsu <[email protected]> Thanks, Yasuaki Ishimatsu > 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); > -- 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/
