From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751179AbeDXWlZ (ORCPT ); Tue, 24 Apr 2018 18:41:25 -0400 Received: from aserp2130.oracle.com ([141.146.126.79]:35366 "EHLO aserp2130.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750779AbeDXWlY (ORCPT ); Tue, 24 Apr 2018 18:41:24 -0400 Subject: Re: [PATCH 3/3] sched: limit cpu search and rotate search window for scalability To: Peter Zijlstra Cc: linux-kernel@vger.kernel.org, mingo@redhat.com, daniel.lezcano@linaro.org, steven.sistare@oracle.com, dhaval.giani@oracle.com, rohit.k.jain@oracle.com References: <20180424004116.28151-1-subhra.mazumdar@oracle.com> <20180424004116.28151-4-subhra.mazumdar@oracle.com> <20180424124801.GS4082@hirez.programming.kicks-ass.net> From: Subhra Mazumdar Message-ID: <212e5820-a9fe-70fb-90b7-d0503342c742@oracle.com> Date: Tue, 24 Apr 2018 15:43:36 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.6.0 MIME-Version: 1.0 In-Reply-To: <20180424124801.GS4082@hirez.programming.kicks-ass.net> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Content-Language: en-US X-Proofpoint-Virus-Version: vendor=nai engine=5900 definitions=8873 signatures=668698 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=0 malwarescore=0 phishscore=0 bulkscore=0 spamscore=0 mlxscore=0 mlxlogscore=680 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1711220000 definitions=main-1804240213 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 04/24/2018 05:48 AM, Peter Zijlstra wrote: > On Mon, Apr 23, 2018 at 05:41:16PM -0700, subhra mazumdar wrote: >> + if (per_cpu(next_cpu, target) != -1) >> + target_tmp = per_cpu(next_cpu, target); >> + else >> + target_tmp = target; >> + > This one; what's the point here? Want to start search from target first time and from the next_cpu next time onwards. If this doesn't many any difference in performance I can change it. Will require re-running all the tests.