On Wed, Jun 28, 2017 at 3:06 PM, Vlastimil Babka <vbabka@xxxxxxx> wrote: > On 06/26/2017 05:58 AM, Wei Yang wrote: >> In commit (9adb62a5df9c0fbef7) "mm/hotplug: correctly setup fallback >> zonelists when creating new pgdat" tries to build the correct zonelist for >> a new added node, while it is not necessary to rebuild it for already exist >> nodes. >> >> In build_zonelists(), it will iterate on nodes with memory. For a new added >> node, it will have memory until node_states_set_node() is called in > > it will not have memory > No memory at this point. > right? > >> online_pages(). >> >> This patch will avoid to rebuild the zonelists for already exist nodes. >> >> Signed-off-by: Wei Yang <richard.weiyang@xxxxxxxxx> > > Sounds correct, as far as the memory hotplug mess allows. > > Acked-by: Vlastimil Babka <vbabka@xxxxxxx> > > Some style nitpicks below: > >> --- >> mm/page_alloc.c | 16 +++++++++------- >> 1 file changed, 9 insertions(+), 7 deletions(-) >> >> diff --git a/mm/page_alloc.c b/mm/page_alloc.c >> index 560eafe8234d..fc8181b44fd8 100644 >> --- a/mm/page_alloc.c >> +++ b/mm/page_alloc.c >> @@ -5200,15 +5200,17 @@ static int __build_all_zonelists(void *data) >> memset(node_load, 0, sizeof(node_load)); >> #endif >> >> - if (self && !node_online(self->node_id)) { >> + /* This node is hotadded and no memory preset yet. > > On multiline comments, the first line should be empty after "/*" > Thanks, I will pay attention next time. > But I see Andrew already fixed that. > >> + * So just build zonelists is fine, no need to touch other nodes. >> + */ >> + if (self && !node_online(self->node_id)) >> build_zonelists(self); >> - } >> - >> - for_each_online_node(nid) { >> - pg_data_t *pgdat = NODE_DATA(nid); >> + else >> + for_each_online_node(nid) { >> + pg_data_t *pgdat = NODE_DATA(nid); >> >> - build_zonelists(pgdat); >> - } >> + build_zonelists(pgdat); >> + } > > Personally I would use { } for the else block, and thus leave them also > for the if block, not sure if this is recommended by the style guide though. > I am not quite sure about this. The checkpatch.py script doesn't complain. Thanks for your comment again~ >> /* >> * Initialize the boot_pagesets that are going to be used >> > -- 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>