Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752816AbbHGLAu (ORCPT ); Fri, 7 Aug 2015 07:00:50 -0400 Received: from casper.infradead.org ([85.118.1.10]:49487 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751004AbbHGK7x (ORCPT ); Fri, 7 Aug 2015 06:59:53 -0400 Date: Fri, 7 Aug 2015 12:59:51 +0200 From: Peter Zijlstra To: Vineet Gupta Cc: linux-kernel@vger.kernel.org Subject: Re: [PATCH] ARCv2: spinlock/rwlock/atomics: reduce 1 instruction in exponential backoff Message-ID: <20150807105951.GG16853@twins.programming.kicks-ass.net> References: <1438935739-9937-1-git-send-email-vgupta@synopsys.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1438935739-9937-1-git-send-email-vgupta@synopsys.com> User-Agent: Mutt/1.5.21 (2012-12-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 474 Lines: 12 On Fri, Aug 07, 2015 at 01:52:19PM +0530, Vineet Gupta wrote: > The increment of delay counter was 2 instructions: > Arithmatic Shfit Left (ASL) + set to 1 on overflow > > This can be done in 1 using ROtate Left (ROL) Cute :-) -- 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/