From: Lorenzo Stoakes Date: Sun, 27 Aug 2023 11:08:48 +0000 (+0100) Subject: mm: refactor si_mem_available() X-Git-Tag: v6.7-rc6-pxa1908~289^2~394 X-Git-Url: https://git.dujemihanovic.xyz/?a=commitdiff_plain;h=80e4a765a770c491e081463c38be927a876e2ce8;p=linux.git mm: refactor si_mem_available() si_mem_available() needlessly places LRU statistics into an array before retrieving only two of them, simply access those directly. In addition, refactor the code so that the blocks of code which calculate the page cache and reclaimable components each resemble one another to clearly indicate we cap both against wmark_low in the same fashion. Link: https://lkml.kernel.org/r/20230827110848.43510-1-lstoakes@gmail.com Signed-off-by: Lorenzo Stoakes Cc: David Hildenbrand Cc: Hugh Dickins Cc: Kefeng Wang Signed-off-by: Andrew Morton --- diff --git a/mm/show_mem.c b/mm/show_mem.c index 4b888b18bdde..ba0808d6917f 100644 --- a/mm/show_mem.c +++ b/mm/show_mem.c @@ -34,13 +34,8 @@ long si_mem_available(void) long available; unsigned long pagecache; unsigned long wmark_low = 0; - unsigned long pages[NR_LRU_LISTS]; unsigned long reclaimable; struct zone *zone; - int lru; - - for (lru = LRU_BASE; lru < NR_LRU_LISTS; lru++) - pages[lru] = global_node_page_state(NR_LRU_BASE + lru); for_each_zone(zone) wmark_low += low_wmark_pages(zone); @@ -56,7 +51,8 @@ long si_mem_available(void) * start swapping or thrashing. Assume at least half of the page * cache, or the low watermark worth of cache, needs to stay. */ - pagecache = pages[LRU_ACTIVE_FILE] + pages[LRU_INACTIVE_FILE]; + pagecache = global_node_page_state(NR_ACTIVE_FILE) + + global_node_page_state(NR_INACTIVE_FILE); pagecache -= min(pagecache / 2, wmark_low); available += pagecache; @@ -67,7 +63,8 @@ long si_mem_available(void) */ reclaimable = global_node_page_state_pages(NR_SLAB_RECLAIMABLE_B) + global_node_page_state(NR_KERNEL_MISC_RECLAIMABLE); - available += reclaimable - min(reclaimable / 2, wmark_low); + reclaimable -= min(reclaimable / 2, wmark_low); + available += reclaimable; if (available < 0) available = 0;