zsmalloc: skip chain size calculation for pow_of_2 classes

If a class size is power of 2 then it wastes no memory and the best configuration is 1 physical page per-zspage. Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Sergey Senozhatsky <[email protected]> Acked-by: Minchan Kim <[email protected]> Cc: Mike Kravetz <[email protected]> Signed-off-by: Andrew Morton <[email protected]>
dereference23 · Jun 18, 2023 · a42e329 · a42e329
1 parent da5d758
commit a42e329
Showing 1 changed file with 3 additions and 0 deletions.
diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c
@@ -2281,6 +2281,9 @@ static int calculate_zspage_chain_size(int class_size)
 	int i, min_waste = INT_MAX;
 	int chain_size = 1;
 
+	if (is_power_of_2(class_size))
+		return chain_size;
+
 	for (i = 1; i <= ZS_MAX_PAGES_PER_ZSPAGE; i++) {
 		int waste;