From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pd0-f181.google.com (mail-pd0-f181.google.com [209.85.192.181]) by kanga.kvack.org (Postfix) with ESMTP id C5E136B006E for ; Fri, 21 Nov 2014 08:43:47 -0500 (EST) Received: by mail-pd0-f181.google.com with SMTP id z10so5348377pdj.40 for ; Fri, 21 Nov 2014 05:43:47 -0800 (PST) Received: from mail-pd0-x236.google.com (mail-pd0-x236.google.com. [2607:f8b0:400e:c02::236]) by mx.google.com with ESMTPS id pu3si8484651pdb.150.2014.11.21.05.43.45 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Fri, 21 Nov 2014 05:43:46 -0800 (PST) Received: by mail-pd0-f182.google.com with SMTP id r10so5390438pdi.27 for ; Fri, 21 Nov 2014 05:43:45 -0800 (PST) From: Mahendran Ganesh Subject: [PATCH v2] mm/zsmalloc: avoid duplicate assignment of prev_class Date: Fri, 21 Nov 2014 21:43:23 +0800 Message-Id: <1416577403-7887-1-git-send-email-opensource.ganesh@gmail.com> Sender: owner-linux-mm@kvack.org List-ID: To: minchan@kernel.org, ngupta@vflare.org, iamjoonsoo.kim@lge.com, ddstreet@ieee.org Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Mahendran Ganesh In zs_create_pool(), prev_class is assigned (ZS_SIZE_CLASSES - 1) times. And the prev_class only references to the previous size_class. So we do not need unnecessary assignement. This patch assigns *prev_class* when a new size_class structure is allocated and uses prev_class to check whether the first class has been allocated. Signed-off-by: Mahendran Ganesh --- v1 -> v2: - follow Dan Streetman's advise to use prev_class to check whether the first class has been allocated - follow Minchan Kim's advise to remove uninitialized_var() --- mm/zsmalloc.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c index b3b57ef..810eda1 100644 --- a/mm/zsmalloc.c +++ b/mm/zsmalloc.c @@ -970,7 +970,7 @@ struct zs_pool *zs_create_pool(gfp_t flags) int size; int pages_per_zspage; struct size_class *class; - struct size_class *prev_class; + struct size_class *prev_class = NULL; size = ZS_MIN_ALLOC_SIZE + i * ZS_SIZE_CLASS_DELTA; if (size > ZS_MAX_ALLOC_SIZE) @@ -986,8 +986,7 @@ struct zs_pool *zs_create_pool(gfp_t flags) * characteristics. So, we makes size_class point to * previous size_class if possible. */ - if (i < ZS_SIZE_CLASSES - 1) { - prev_class = pool->size_class[i + 1]; + if (prev_class) { if (can_merge(prev_class, size, pages_per_zspage)) { pool->size_class[i] = prev_class; continue; @@ -1003,6 +1002,8 @@ struct zs_pool *zs_create_pool(gfp_t flags) class->pages_per_zspage = pages_per_zspage; spin_lock_init(&class->lock); pool->size_class[i] = class; + + prev_class = class; } pool->flags = flags; -- 1.7.9.5 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org