From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pd0-f180.google.com (mail-pd0-f180.google.com [209.85.192.180]) by kanga.kvack.org (Postfix) with ESMTP id 258896B0038 for ; Tue, 25 Nov 2014 08:01:02 -0500 (EST) Received: by mail-pd0-f180.google.com with SMTP id p10so545251pdj.11 for ; Tue, 25 Nov 2014 05:01:01 -0800 (PST) Received: from mail-pa0-x231.google.com (mail-pa0-x231.google.com. [2607:f8b0:400e:c03::231]) by mx.google.com with ESMTPS id je7si1926464pbd.15.2014.11.25.05.01.00 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Tue, 25 Nov 2014 05:01:00 -0800 (PST) Received: by mail-pa0-f49.google.com with SMTP id eu11so546464pac.8 for ; Tue, 25 Nov 2014 05:01:00 -0800 (PST) From: Ganesh Mahendran Subject: [PATCH v3] mm/zsmalloc: avoid duplicate assignment of prev_class Date: Tue, 25 Nov 2014 21:00:44 +0800 Message-Id: <1416920444-4181-1-git-send-email-opensource.ganesh@gmail.com> Sender: owner-linux-mm@kvack.org List-ID: To: minchan@kernel.org, ngupta@vflare.org, ddstreet@ieee.org Cc: akpm@linux-foundation.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Ganesh Mahendran 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: Ganesh Mahendran Cc: Minchan Kim Cc: Nitin Gupta Cc: Dan Streetman --- 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() v2 -> v3: - move *prev_class* definition out of the loop - Dan --- mm/zsmalloc.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c index 83ecdb6..de1320e 100644 --- a/mm/zsmalloc.c +++ b/mm/zsmalloc.c @@ -966,6 +966,7 @@ struct zs_pool *zs_create_pool(gfp_t flags) { int i, ovhd_size; struct zs_pool *pool; + struct size_class *prev_class = NULL; ovhd_size = roundup(sizeof(*pool), PAGE_SIZE); pool = kzalloc(ovhd_size, GFP_KERNEL); @@ -980,7 +981,6 @@ struct zs_pool *zs_create_pool(gfp_t flags) int size; int pages_per_zspage; struct size_class *class; - struct size_class *prev_class; size = ZS_MIN_ALLOC_SIZE + i * ZS_SIZE_CLASS_DELTA; if (size > ZS_MAX_ALLOC_SIZE) @@ -996,8 +996,7 @@ 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; @@ -1013,6 +1012,8 @@ 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