From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752487AbcAFMaS (ORCPT ); Wed, 6 Jan 2016 07:30:18 -0500 Received: from foss.arm.com ([217.140.101.70]:34858 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752094AbcAFMaP (ORCPT ); Wed, 6 Jan 2016 07:30:15 -0500 Date: Wed, 6 Jan 2016 12:30:11 +0000 From: Catalin Marinas To: Mark Rutland Cc: cmetcalf@ezchip.com, will.deacon@arm.com, linux-kernel@vger.kernel.org, luto@amacapital.net, linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH 2/2] arm64: factor work_pending state machine to C Message-ID: <20160106123011.GN6301@e104818-lin.cambridge.arm.com> References: <20160105172106.GA7088@leverpostej> <1452015215-29506-2-git-send-email-mark.rutland@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1452015215-29506-2-git-send-email-mark.rutland@arm.com> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jan 05, 2016 at 05:33:35PM +0000, Mark Rutland wrote: > Currently ret_fast_syscall, work_pending, and ret_to_user form an ad-hoc > state machine that can be difficult to reason about due to duplicated > code and a large number of branch targets. > > This patch factors the common logic out into the existing > do_notify_resume function, converting the code to C in the process, > making the code more legible. > > This patch tries to mirror the existing behaviour as closely as possible > while using the usual C control flow primitives. There should be no > functional change as a result of this patch. > > Signed-off-by: Mark Rutland > Cc: Catalin Marinas > Cc: Chris Metcalf > Cc: Will Deacon This is definitely cleaner. The only downside is slightly more expensive ret_fast_syscall. I guess it's not noticeable (though we could do some quick benchmark like getpid in a loop). Anyway, I'm fine with the patch: Acked-by: Catalin Marinas