Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754656AbbETTuw (ORCPT ); Wed, 20 May 2015 15:50:52 -0400 Received: from s159.web-hosting.com ([68.65.121.203]:46306 "EHLO s159.web-hosting.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753643AbbETTuu (ORCPT ); Wed, 20 May 2015 15:50:50 -0400 MIME-Version: 1.0 In-Reply-To: <555CE3C4.7010406@kernel.dk> References: <1431976472-27596-1-git-send-email-jteki@openedev.com> <555CDF0A.9080006@kernel.dk> <555CE3C4.7010406@kernel.dk> Date: Thu, 21 May 2015 01:20:47 +0530 Message-ID: Subject: Re: [PATCH] block: Use BIT macro from include/linux/bitops.h From: Jagan Teki To: Jens Axboe Cc: "linux-kernel@vger.kernel.org" , Wolfram Sang Content-Type: text/plain; charset=UTF-8 X-OutGoing-Spam-Status: No, score=-1.0 X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - server159.web-hosting.com X-AntiAbuse: Original Domain - vger.kernel.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - openedev.com X-Get-Message-Sender-Via: server159.web-hosting.com: authenticated_id: jteki@openedev.com X-Source: X-Source-Args: X-Source-Dir: X-From-Rewrite: unmodified, already matched Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1204 Lines: 37 On 21 May 2015 at 01:13, Jens Axboe wrote: > On 05/20/2015 01:41 PM, Jagan Teki wrote: >> >> On 21 May 2015 at 00:52, Jens Axboe wrote: >>> >>> On 05/18/2015 01:14 PM, Jagan Teki wrote: >>>> >>>> >>>> Replace (1 << nr) to BIT(nr) where nr = 0, 1, 2 .... 31 >>> >>> >>> >>> I don't like it, I think it hurts readability. >> >> >> What do you mean by don't like, using kernel defined macro instead of >> numerical assignments huts readability? > > > In the context of the patch, BIT(0) == (1 << 0) is obvious. But if I just > came across BIT(7) in the code, I'd have to check, whereas anyone would > immediately know that (1 << 7) is the 7th bit set. Hence, readability is > worse, and that's important. I don't how that BIT(7) is tricky to understand as BIT(0) implies to be set 0th bit. If understanding of BIT(0) is same like to be as BIT(7) and these were simplified macro's used most of the code in kernel. -- Jagan. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/