From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752575AbbAaLi7 (ORCPT ); Sat, 31 Jan 2015 06:38:59 -0500 Received: from mail-pa0-f54.google.com ([209.85.220.54]:53521 "EHLO mail-pa0-f54.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750707AbbAaLi6 (ORCPT ); Sat, 31 Jan 2015 06:38:58 -0500 Date: Sat, 31 Jan 2015 20:39:31 +0900 From: Sergey Senozhatsky To: Sergey Senozhatsky Cc: "David S. Miller" , Andrew Morton , Amir Vadai , linux-kernel@vger.kernel.org Subject: Re: [PATCH] cpumask: kill loop in cpumask_next_and() Message-ID: <20150131113931.GC2299@swordfish> References: <1421335361-1752-1-git-send-email-sergey.senozhatsky@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1421335361-1752-1-git-send-email-sergey.senozhatsky@gmail.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 (01/16/15 00:22), Sergey Senozhatsky wrote: > > cpumask_next_and() does cpumask_next() src1 in a loop and tests if found > cpu is alsop present in src2. remove that loop and perform cpumask_and() > of src1 and src2 first and use to find cpumask_next() intead. > Hello, did you have any chance to review this patch? let me know if you want me to resend (I made some nasty typos in the commit message). -ss > Signed-off-by: Sergey Senozhatsky > --- > lib/cpumask.c | 9 +++++---- > 1 file changed, 5 insertions(+), 4 deletions(-) > > diff --git a/lib/cpumask.c b/lib/cpumask.c > index b6513a9..5ab1553 100644 > --- a/lib/cpumask.c > +++ b/lib/cpumask.c > @@ -37,10 +37,11 @@ EXPORT_SYMBOL(__next_cpu_nr); > int cpumask_next_and(int n, const struct cpumask *src1p, > const struct cpumask *src2p) > { > - while ((n = cpumask_next(n, src1p)) < nr_cpu_ids) > - if (cpumask_test_cpu(n, src2p)) > - break; > - return n; > + struct cpumask tmp; > + > + if (cpumask_and(&tmp, src1p, src2p)) > + return cpumask_next(n, &tmp); > + return nr_cpu_ids; > } > EXPORT_SYMBOL(cpumask_next_and); > > -- > 2.2.2 >