From c091dd963f99a4ae1a5c31bff68e5c2ebd786b07 Mon Sep 17 00:00:00 2001 From: Baoquan He Date: Tue, 26 Mar 2024 14:11:28 +0800 Subject: mm/init: remove the unnecessary special treatment for memory-less node Because memory-less node's ->node_present_pages and its zone's ->present_pages are all 0, the judgement before calling node_set_state() to set N_MEMORY, N_HIGH_MEMORY, N_NORMAL_MEMORY for node is enough to skip memory-less node. The 'continue;' statement inside for_each_node() loop of free_area_init() is gilding the lily. Here, remove the special handling to make memory-less node share the same code flow as normal node. And also rephrase the code comments above the 'continue' statement and move them above above line 'if (pgdat->node_present_pages)'. [bhe@redhat.com: redo code comments, per Mike] Link: https://lkml.kernel.org/r/ZhYJAVQRYJSTKZng@MiWiFi-R3L-srv Link: https://lkml.kernel.org/r/20240326061134.1055295-3-bhe@redhat.com Signed-off-by: Baoquan He Cc: Mel Gorman Cc: "Mike Rapoport (IBM)" Signed-off-by: Andrew Morton --- mm/mm_init.c | 27 +++++++++++---------------- 1 file changed, 11 insertions(+), 16 deletions(-) diff --git a/mm/mm_init.c b/mm/mm_init.c index 0d32bcc301e2..0fe466abde43 100644 --- a/mm/mm_init.c +++ b/mm/mm_init.c @@ -1835,28 +1835,23 @@ void __init free_area_init(unsigned long *max_zone_pfn) panic("Cannot allocate %zuB for node %d.\n", sizeof(*pgdat), nid); arch_refresh_nodedata(nid, pgdat); - free_area_init_node(nid); - - /* - * We do not want to confuse userspace by sysfs - * files/directories for node without any memory - * attached to it, so this node is not marked as - * N_MEMORY and not marked online so that no sysfs - * hierarchy will be created via register_one_node for - * it. The pgdat will get fully initialized by - * hotadd_init_pgdat() when memory is hotplugged into - * this node. - */ - continue; } pgdat = NODE_DATA(nid); free_area_init_node(nid); - /* Any memory on that node */ - if (pgdat->node_present_pages) + /* + * No sysfs hierarcy will be created via register_one_node() + *for memory-less node because here it's not marked as N_MEMORY + *and won't be set online later. The benefit is userspace + *program won't be confused by sysfs files/directories of + *memory-less node. The pgdat will get fully initialized by + *hotadd_init_pgdat() when memory is hotplugged into this node. + */ + if (pgdat->node_present_pages) { node_set_state(nid, N_MEMORY); - check_for_memory(pgdat); + check_for_memory(pgdat); + } } calc_nr_kernel_pages(); -- cgit v1.2.3