From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pa0-f43.google.com (mail-pa0-f43.google.com [209.85.220.43]) by kanga.kvack.org (Postfix) with ESMTP id CED3A6B006E for ; Thu, 20 Nov 2014 22:54:38 -0500 (EST) Received: by mail-pa0-f43.google.com with SMTP id kx10so3969541pab.30 for ; Thu, 20 Nov 2014 19:54:38 -0800 (PST) Received: from lgeamrelo01.lge.com (lgeamrelo01.lge.com. [156.147.1.125]) by mx.google.com with ESMTP id ic2si2869064pad.205.2014.11.20.19.54.36 for ; Thu, 20 Nov 2014 19:54:37 -0800 (PST) Date: Fri, 21 Nov 2014 12:54:42 +0900 From: Minchan Kim Subject: Re: [RFC PATCH] mm/zsmalloc: remove unnecessary check Message-ID: <20141121035442.GB10123@bbox> References: <1416489716-9967-1-git-send-email-opensource.ganesh@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <1416489716-9967-1-git-send-email-opensource.ganesh@gmail.com> Sender: owner-linux-mm@kvack.org List-ID: To: Mahendran Ganesh Cc: ngupta@vflare.org, iamjoonsoo.kim@lge.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org On Thu, Nov 20, 2014 at 09:21:56PM +0800, Mahendran Ganesh wrote: > ZS_SIZE_CLASSES is calc by: > ((ZS_MAX_ALLOC_SIZE - ZS_MIN_ALLOC_SIZE) / ZS_SIZE_CLASS_DELTA + 1) > > So when i is in [0, ZS_SIZE_CLASSES - 1), the size: > size = ZS_MIN_ALLOC_SIZE + i * ZS_SIZE_CLASS_DELTA > will not be greater than ZS_MAX_ALLOC_SIZE > > This patch removes the unnecessary check. It depends on ZS_MIN_ALLOC_SIZE. For example, we would change min to 8 but MAX is still 4096. ZS_SIZE_CLASSES is (4096 - 8) / 16 + 1 = 256 so 8 + 255 * 16 = 4088, which exceeds the max. > > Signed-off-by: Mahendran Ganesh > --- > mm/zsmalloc.c | 2 -- > 1 file changed, 2 deletions(-) > > diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c > index b3b57ef..f2279e2 100644 > --- a/mm/zsmalloc.c > +++ b/mm/zsmalloc.c > @@ -973,8 +973,6 @@ struct zs_pool *zs_create_pool(gfp_t flags) > struct size_class *prev_class; > > size = ZS_MIN_ALLOC_SIZE + i * ZS_SIZE_CLASS_DELTA; > - if (size > ZS_MAX_ALLOC_SIZE) > - size = ZS_MAX_ALLOC_SIZE; > pages_per_zspage = get_pages_per_zspage(size); > > /* > -- > 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 -- Kind regards, Minchan Kim -- 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