From: Oscar Salvador <[email protected]> This patch tries to simplify node_states_check_changes_offline and make the code more understandable by:
- Removing the if (N_MEMORY == N_NORMAL_MEMORY) wrong statement - Removing the if (N_MEMORY == N_HIGH_MEMORY) wrong statement - Re-structure the code a bit - Removing confusing comments Signed-off-by: Oscar Salvador <[email protected]> --- mm/memory_hotplug.c | 81 ++++++++++++++++++++++------------------------------- 1 file changed, 33 insertions(+), 48 deletions(-) diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index 006a7b817724..b45bc681e6db 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -1487,51 +1487,40 @@ static void node_states_check_changes_offline(unsigned long nr_pages, enum zone_type zt, zone_last = ZONE_NORMAL; /* - * If we have HIGHMEM or movable node, node_states[N_NORMAL_MEMORY] - * contains nodes which have zones of 0...ZONE_NORMAL, - * set zone_last to ZONE_NORMAL. - * - * If we don't have HIGHMEM nor movable node, - * node_states[N_NORMAL_MEMORY] contains nodes which have zones of - * 0...ZONE_MOVABLE, set zone_last to ZONE_MOVABLE. + * If the current zone is whithin (0..ZONE_NORMAL], + * check if the amount of pages that are going to be + * offlined is above or equal to the sum of the present + * pages of these zones. + * If that happens, we need to take this node out of + * node_state[N_NORMAL_MEMORY] */ - if (N_MEMORY == N_NORMAL_MEMORY) - zone_last = ZONE_MOVABLE; + if (zone_idx(zone) <= zone_last) { + for (zt = 0; zt <= zone_last; zt++) + present_pages += pgdat->node_zones[zt].present_pages; - /* - * check whether node_states[N_NORMAL_MEMORY] will be changed. - * If the memory to be offline is in a zone of 0...zone_last, - * and it is the last present memory, 0...zone_last will - * become empty after offline , thus we can determind we will - * need to clear the node from node_states[N_NORMAL_MEMORY]. - */ - for (zt = 0; zt <= zone_last; zt++) - present_pages += pgdat->node_zones[zt].present_pages; - if (zone_idx(zone) <= zone_last && nr_pages >= present_pages) - arg->status_change_nid_normal = zone_to_nid(zone); - else - arg->status_change_nid_normal = -1; + if (nr_pages >= present_pages) + arg->status_change_nid_normal = zone_to_nid(zone); + else + arg->status_change_nid_normal = -1; + } #ifdef CONFIG_HIGHMEM /* - * If we have movable node, node_states[N_HIGH_MEMORY] - * contains nodes which have zones of 0...ZONE_HIGHMEM, - * set zone_last to ZONE_HIGHMEM. - * - * If we don't have movable node, node_states[N_NORMAL_MEMORY] - * contains nodes which have zones of 0...ZONE_MOVABLE, - * set zone_last to ZONE_MOVABLE. + * If the current zone is whithin (0..ZONE_HIGHMEM], check if + * the amount of pages that are going to be offlined is above + * or equal to the sum of the present pages of these zones. + * If that happens, we need to take this node out of + * node_state[N_HIGH_MEMORY] */ - zone_last = ZONE_HIGHMEM; - if (N_MEMORY == N_HIGH_MEMORY) - zone_last = ZONE_MOVABLE; - - for (; zt <= zone_last; zt++) + if (zone_idx(zone) <= ZONE_HIGHMEM) { + zt = ZONE_HIGHMEM; present_pages += pgdat->node_zones[zt].present_pages; - if (zone_idx(zone) <= zone_last && nr_pages >= present_pages) - arg->status_change_nid_high = zone_to_nid(zone); - else - arg->status_change_nid_high = -1; + + if (nr_pages >= present_pages) + arg->status_change_nid_high = zone_to_nid(zone); + else + arg->status_change_nid_high = -1; + } #else /* * When !CONFIG_HIGHMEM, N_HIGH_MEMORY equals N_NORMAL_MEMORY @@ -1541,18 +1530,14 @@ static void node_states_check_changes_offline(unsigned long nr_pages, #endif /* - * node_states[N_HIGH_MEMORY] contains nodes which have 0...ZONE_MOVABLE + * Count pages from ZONE_MOVABLE as well. + * If the amount of pages that are going to be offlined is above + * or equal the sum of the present pages of all zones, we need + * to remove this node from node_state[N_MEMORY] */ - zone_last = ZONE_MOVABLE; + zt = ZONE_MOVABLE; + present_pages += pgdat->node_zones[zt].present_pages; - /* - * check whether node_states[N_HIGH_MEMORY] will be changed - * If we try to offline the last present @nr_pages from the node, - * we can determind we will need to clear the node from - * node_states[N_HIGH_MEMORY]. - */ - for (; zt <= zone_last; zt++) - present_pages += pgdat->node_zones[zt].present_pages; if (nr_pages >= present_pages) arg->status_change_nid = zone_to_nid(zone); else -- 2.13.6
