From 2e655dfbb8230db13d572c59dc32e3e413ba65d5 Mon Sep 17 00:00:00 2001 From: Ganesh Mahendran Date: Thu, 28 Jul 2016 15:47:51 -0700 Subject: [PATCH] mm/zsmalloc: avoid calculate max objects of zspage twice Currently, if a class can not be merged, the max objects of zspage in that class may be calculated twice. This patch calculate max objects of zspage at the begin, and pass the value to can_merge() to decide whether the class can be merged. Also this patch remove function get_maxobj_per_zspage(), as there is no other place to call this function. Link: http://lkml.kernel.org/r/1467882338-4300-4-git-send-email-opensource.ganesh@gmail.com Signed-off-by: Ganesh Mahendran Reviewed-by: Sergey Senozhatsky Acked-by: Minchan Kim Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/zsmalloc.c | 24 ++++++++---------------- 1 file changed, 8 insertions(+), 16 deletions(-) diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c index 8ba3c07be..731e84b93 100644 --- a/mm/zsmalloc.c +++ b/mm/zsmalloc.c @@ -478,11 +478,6 @@ static struct zpool_driver zs_zpool_driver = { MODULE_ALIAS("zpool-zsmalloc"); #endif /* CONFIG_ZPOOL */ -static unsigned int get_maxobj_per_zspage(int size, int pages_per_zspage) -{ - return pages_per_zspage * PAGE_SIZE / size; -} - /* per-cpu VM mapping areas for zspage accesses that cross page boundaries */ static DEFINE_PER_CPU(struct mapping_area, zs_map_area); @@ -1372,16 +1367,14 @@ static void init_zs_size_classes(void) zs_size_classes = nr; } -static bool can_merge(struct size_class *prev, int size, int pages_per_zspage) +static bool can_merge(struct size_class *prev, int pages_per_zspage, + int objs_per_zspage) { - if (prev->pages_per_zspage != pages_per_zspage) - return false; + if (prev->pages_per_zspage == pages_per_zspage && + prev->objs_per_zspage == objs_per_zspage) + return true; - if (prev->objs_per_zspage - != get_maxobj_per_zspage(size, pages_per_zspage)) - return false; - - return true; + return false; } static bool zspage_full(struct size_class *class, struct zspage *zspage) @@ -2523,7 +2516,7 @@ struct zs_pool *zs_create_pool(const char *name) * previous size_class if possible. */ if (prev_class) { - if (can_merge(prev_class, size, pages_per_zspage)) { + if (can_merge(prev_class, pages_per_zspage, objs_per_zspage)) { pool->size_class[i] = prev_class; continue; } @@ -2536,8 +2529,7 @@ struct zs_pool *zs_create_pool(const char *name) class->size = size; class->index = i; class->pages_per_zspage = pages_per_zspage; - class->objs_per_zspage = get_maxobj_per_zspage(class->size, - class->pages_per_zspage); + class->objs_per_zspage = objs_per_zspage; spin_lock_init(&class->lock); pool->size_class[i] = class; for (fullness = ZS_EMPTY; fullness < NR_ZS_FULLNESS;