From c3a5c77afefa697bf87f15272c7257e1574cad56 Mon Sep 17 00:00:00 2001 From: Wei Yang Date: Fri, 28 Dec 2018 00:37:16 -0800 Subject: [PATCH] lib/show_mem.c: drop pgdat_resize_lock in show_mem() Function show_mem() is used to print system memory status when user requires or fail to allocate memory. Generally, this is a best effort information so any races with memory hotplug (or very theoretically an early initialization) should be tolerable and the worst that could happen is to print an imprecise node state. Drop the resize lock because this is the only place which might hold the lock from the interrupt context and so all other callers might use a simple spinlock. Even though this doesn't solve any real issue it makes the code easier to follow and tiny more effective. Link: http://lkml.kernel.org/r/20181129235532.9328-1-richard.weiyang@gmail.com Signed-off-by: Wei Yang Acked-by: Michal Hocko Reviewed-by: Oscar Salvador Cc: Johannes Weiner Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- lib/show_mem.c | 3 --- 1 file changed, 3 deletions(-) diff --git a/lib/show_mem.c b/lib/show_mem.c index eefe67d50e84..6a042f53e7bb 100644 --- a/lib/show_mem.c +++ b/lib/show_mem.c @@ -18,10 +18,8 @@ void show_mem(unsigned int filter, nodemask_t *nodemask) show_free_areas(filter, nodemask); for_each_online_pgdat(pgdat) { - unsigned long flags; int zoneid; - pgdat_resize_lock(pgdat, &flags); for (zoneid = 0; zoneid < MAX_NR_ZONES; zoneid++) { struct zone *zone = &pgdat->node_zones[zoneid]; if (!populated_zone(zone)) @@ -33,7 +31,6 @@ void show_mem(unsigned int filter, nodemask_t *nodemask) if (is_highmem_idx(zoneid)) highmem += zone->present_pages; } - pgdat_resize_unlock(pgdat, &flags); } printk("%lu pages RAM\n", total); -- 2.30.2