From: Ganesh Mahendran <opensource.ganesh@xxxxxxxxx> Subject: 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@xxxxxxxxx Signed-off-by: Ganesh Mahendran <opensource.ganesh@xxxxxxxxx> Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@xxxxxxxxx> Acked-by: Minchan Kim <minchan@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/zsmalloc.c | 26 ++++++++++---------------- 1 file changed, 10 insertions(+), 16 deletions(-) diff -puN mm/zsmalloc.c~mm-zsmalloc-avoid-calculate-max-objects-of-zspage-twice mm/zsmalloc.c --- a/mm/zsmalloc.c~mm-zsmalloc-avoid-calculate-max-objects-of-zspage-twice +++ a/mm/zsmalloc.c @@ -467,11 +467,6 @@ static struct zpool_driver zs_zpool_driv 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); @@ -1359,16 +1354,14 @@ 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) @@ -2438,6 +2431,7 @@ struct zs_pool *zs_create_pool(const cha for (i = zs_size_classes - 1; i >= 0; i--) { int size; int pages_per_zspage; + int objs_per_zspage; struct size_class *class; int fullness = 0; @@ -2445,6 +2439,7 @@ struct zs_pool *zs_create_pool(const cha if (size > ZS_MAX_ALLOC_SIZE) size = ZS_MAX_ALLOC_SIZE; pages_per_zspage = get_pages_per_zspage(size); + objs_per_zspage = pages_per_zspage * PAGE_SIZE / size; /* * size_class is used for normal zsmalloc operation such @@ -2456,7 +2451,7 @@ struct zs_pool *zs_create_pool(const cha * 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; } @@ -2469,8 +2464,7 @@ struct zs_pool *zs_create_pool(const cha 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; _ -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
