From 58f171174625150f3aaad0cddd3e365270b8e1b8 Mon Sep 17 00:00:00 2001 From: Sergey Senozhatsky Date: Tue, 8 Sep 2015 15:04:44 -0700 Subject: [PATCH] zsmalloc: partial page ordering within a fullness_list We want to see more ZS_FULL pages and less ZS_ALMOST_{FULL, EMPTY} pages. Put a page with higher ->inuse count first within its ->fullness_list, which will give us better chances to fill up this page with new objects (find_get_zspage() return ->fullness_list head for new object allocation), so some zspages will become ZS_ALMOST_FULL/ZS_FULL quicker. It performs a trivial and cheap ->inuse compare which does not slow down zsmalloc and in the worst case keeps the list pages in no particular order. A more expensive solution could sort fullness_list by ->inuse count. [minchan@kernel.org: code adjustments] Signed-off-by: Sergey Senozhatsky Cc: Minchan Kim Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/zsmalloc.c | 19 ++++++++++++++----- 1 file changed, 14 insertions(+), 5 deletions(-) diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c index 27b9661c8fa6..615b9b9b45eb 100644 --- a/mm/zsmalloc.c +++ b/mm/zsmalloc.c @@ -643,13 +643,22 @@ static void insert_zspage(struct page *page, struct size_class *class, if (fullness >= _ZS_NR_FULLNESS_GROUPS) return; - head = &class->fullness_list[fullness]; - if (*head) - list_add_tail(&page->lru, &(*head)->lru); - - *head = page; zs_stat_inc(class, fullness == ZS_ALMOST_EMPTY ? CLASS_ALMOST_EMPTY : CLASS_ALMOST_FULL, 1); + + head = &class->fullness_list[fullness]; + if (!*head) { + *head = page; + return; + } + + /* + * We want to see more ZS_FULL pages and less almost + * empty/full. Put pages with higher ->inuse first. + */ + list_add_tail(&page->lru, &(*head)->lru); + if (page->inuse >= (*head)->inuse) + *head = page; } /*