Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757971AbYLKRlX (ORCPT ); Thu, 11 Dec 2008 12:41:23 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1757672AbYLKRj5 (ORCPT ); Thu, 11 Dec 2008 12:39:57 -0500 Received: from e28smtp04.in.ibm.com ([59.145.155.4]:57969 "EHLO e28smtp04.in.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757640AbYLKRjz (ORCPT ); Thu, 11 Dec 2008 12:39:55 -0500 From: Vaidyanathan Srinivasan Subject: [RFC PATCH v5 6/7] sched: add SD_BALANCE_NEWIDLE at MC and CPU level for sched_mc>0 To: Linux Kernel , Suresh B Siddha , Venkatesh Pallipadi , Peter Zijlstra Cc: Ingo Molnar , Dipankar Sarma , Balbir Singh , Vatsa , Gautham R Shenoy , Andi Kleen , David Collier-Brown , Tim Connors , Max Krasnyansky , Gregory Haskins , Vaidyanathan Srinivasan Date: Thu, 11 Dec 2008 23:13:17 +0530 Message-ID: <20081211174317.2020.87473.stgit@drishya.in.ibm.com> In-Reply-To: <20081211173831.2020.57550.stgit@drishya.in.ibm.com> References: <20081211173831.2020.57550.stgit@drishya.in.ibm.com> User-Agent: StGIT/0.14.2 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2898 Lines: 83 Add SD_BALANCE_NEWIDLE flag at MC level and CPU level if sched_mc is set. This helps power savings and will not affect performance when sched_mc=0 Ingo and Mike Galbraith have optimised the SD flags by removing SD_BALANCE_NEWIDLE at MC and CPU level. This helps performance but hurts power savings since this slows down task consolidation by reducing the number of times load_balance is run. sched: fine-tune SD_MC_INIT commit 14800984706bf6936bbec5187f736e928be5c218 Author: Mike Galbraith Date: Fri Nov 7 15:26:50 2008 +0100 sched: re-tune balancing -- revert commit 9fcd18c9e63e325dbd2b4c726623f760788d5aa8 Author: Ingo Molnar Date: Wed Nov 5 16:52:08 2008 +0100 This patch selectively enables SD_BALANCE_NEWIDLE flag only when sched_mc is set to 1 or 2. This helps power savings by task consolidation and also does not hurt performance at sched_mc=0 where all power saving optimisations are turned off. Signed-off-by: Vaidyanathan Srinivasan --- include/linux/sched.h | 10 ++++++++++ include/linux/topology.h | 6 ++++-- 2 files changed, 14 insertions(+), 2 deletions(-) diff --git a/include/linux/sched.h b/include/linux/sched.h index 888f2b2..e894892 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -782,6 +782,16 @@ enum powersavings_balance_level { ((sched_mc_power_savings || sched_smt_power_savings) ? \ SD_POWERSAVINGS_BALANCE : 0) +/* + * Optimise SD flags for power savings: + * SD_BALANCE_NEWIDLE helps agressive task consolidation and power savings. + * Keep default SD flags if sched_{smt,mc}_power_saving=0 + */ + +#define POWERSAVING_SD_FLAGS \ + ((sched_mc_power_savings || sched_smt_power_savings) ? \ + SD_BALANCE_NEWIDLE : 0) + #define test_sd_parent(sd, flag) ((sd->parent && \ (sd->parent->flags & flag)) ? 1 : 0) diff --git a/include/linux/topology.h b/include/linux/topology.h index 117f1b7..26c608c 100644 --- a/include/linux/topology.h +++ b/include/linux/topology.h @@ -125,7 +125,8 @@ void arch_update_cpu_topology(void); | SD_WAKE_AFFINE \ | SD_WAKE_BALANCE \ | SD_SHARE_PKG_RESOURCES\ - | BALANCE_FOR_MC_POWER, \ + | BALANCE_FOR_MC_POWER \ + | POWERSAVING_SD_FLAGS, \ .last_balance = jiffies, \ .balance_interval = 1, \ } @@ -150,7 +151,8 @@ void arch_update_cpu_topology(void); | SD_BALANCE_FORK \ | SD_WAKE_AFFINE \ | SD_WAKE_BALANCE \ - | BALANCE_FOR_PKG_POWER,\ + | BALANCE_FOR_PKG_POWER \ + | POWERSAVING_SD_FLAGS, \ .last_balance = jiffies, \ .balance_interval = 1, \ } -- 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/