From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Gustavo A. R. Silva" Subject: Re: [PATCH] ext4: use swap macro in mext_page_double_lock Date: Sun, 22 Jul 2018 18:30:53 -0500 Message-ID: References: <20180709131600.GA9138@embeddedor.com> <20180722221911.GC3358@thunk.org> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit To: "Theodore Y. Ts'o" , Andreas Dilger , linux-ext4@vger.kernel.org, linux-kernel@vger.kernel.org Return-path: In-Reply-To: <20180722221911.GC3358@thunk.org> Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-ext4.vger.kernel.org Hi Theodore, On 07/22/2018 05:19 PM, Theodore Y. Ts'o wrote: > On Mon, Jul 09, 2018 at 08:16:00AM -0500, Gustavo A. R. Silva wrote: >> Make use of the swap macro and remove unnecessary variable *tmp*. >> This makes the code easier to read and maintain. Also, reduces the >> stack usage. >> >> This code was detected with the help of Coccinelle. >> >> Signed-off-by: Gustavo A. R. Silva > > It doesn't actually reduce stack usage. Look at the definition of > swap() in include/linux/kernel.h: > > #define swap(a, b) \ > do { typeof(a) __tmp = (a); (a) = (b); (b) = __tmp; } while (0) > > It removes the variable "tmp", and replace it with "__tmp". > > It slightly reduces the number of lines of code, so it slightly makes > the code easier to maintainer. But I think you are really > over-promising how much this commit helps. > I'll remove that part from the changelog and send it again. Thanks -- Gustavo