From: David Hildenbrand <david@xxxxxxxxxx> Subject: mm: remove vm_total_pages The global variable "vm_total_pages" is a relic from older days. There is only a single user that reads the variable - build_all_zonelists() - and the first thing it does is update it. Use a local variable in build_all_zonelists() instead and remove the global variable. Link: http://lkml.kernel.org/r/20200619132410.23859-2-david@xxxxxxxxxx Signed-off-by: David Hildenbrand <david@xxxxxxxxxx> Reviewed-by: Wei Yang <richard.weiyang@xxxxxxxxx> Acked-by: Michal Hocko <mhocko@xxxxxxxx> Reviewed-by: Pankaj Gupta <pankaj.gupta.linux@xxxxxxxxx> Reviewed-by: Mike Rapoport <rppt@xxxxxxxxxxxxx> Cc: Johannes Weiner <hannes@xxxxxxxxxxx> Cc: Huang Ying <ying.huang@xxxxxxxxx> Cc: Minchan Kim <minchan@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- include/linux/swap.h | 1 - mm/memory_hotplug.c | 3 --- mm/page-writeback.c | 6 ++---- mm/page_alloc.c | 2 ++ mm/vmscan.c | 5 ----- 5 files changed, 4 insertions(+), 13 deletions(-) --- a/include/linux/swap.h~mm-drop-vm_total_pages +++ a/include/linux/swap.h @@ -372,7 +372,6 @@ extern unsigned long mem_cgroup_shrink_n extern unsigned long shrink_all_memory(unsigned long nr_pages); extern int vm_swappiness; extern int remove_mapping(struct address_space *mapping, struct page *page); -extern unsigned long vm_total_pages; extern unsigned long reclaim_pages(struct list_head *page_list); #ifdef CONFIG_NUMA --- a/mm/memory_hotplug.c~mm-drop-vm_total_pages +++ a/mm/memory_hotplug.c @@ -844,8 +844,6 @@ int __ref online_pages(unsigned long pfn kswapd_run(nid); kcompactd_run(nid); - vm_total_pages = nr_free_pagecache_pages(); - writeback_set_ratelimit(); memory_notify(MEM_ONLINE, &arg); @@ -1595,7 +1593,6 @@ static int __ref __offline_pages(unsigne kcompactd_stop(node); } - vm_total_pages = nr_free_pagecache_pages(); writeback_set_ratelimit(); memory_notify(MEM_OFFLINE, &arg); --- a/mm/page_alloc.c~mm-drop-vm_total_pages +++ a/mm/page_alloc.c @@ -5912,6 +5912,8 @@ build_all_zonelists_init(void) */ void __ref build_all_zonelists(pg_data_t *pgdat) { + unsigned long vm_total_pages; + if (system_state == SYSTEM_BOOTING) { build_all_zonelists_init(); } else { --- a/mm/page-writeback.c~mm-drop-vm_total_pages +++ a/mm/page-writeback.c @@ -2076,13 +2076,11 @@ static int page_writeback_cpu_online(uns * Called early on to tune the page writeback dirty limits. * * We used to scale dirty pages according to how total memory - * related to pages that could be allocated for buffers (by - * comparing nr_free_buffer_pages() to vm_total_pages. + * related to pages that could be allocated for buffers. * * However, that was when we used "dirty_ratio" to scale with * all memory, and we don't do that any more. "dirty_ratio" - * is now applied to total non-HIGHPAGE memory (by subtracting - * totalhigh_pages from vm_total_pages), and as such we can't + * is now applied to total non-HIGHPAGE memory, and as such we can't * get into the old insane situation any more where we had * large amounts of dirty pages compared to a small amount of * non-HIGHMEM memory. --- a/mm/vmscan.c~mm-drop-vm_total_pages +++ a/mm/vmscan.c @@ -170,11 +170,6 @@ struct scan_control { * From 0 .. 200. Higher means more swappy. */ int vm_swappiness = 60; -/* - * The total number of pages which are beyond the high watermark within all - * zones. - */ -unsigned long vm_total_pages; static void set_task_reclaim_state(struct task_struct *task, struct reclaim_state *rs) _
