From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754773AbcHSBer (ORCPT ); Thu, 18 Aug 2016 21:34:47 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:25424 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1754073AbcHSBeo (ORCPT ); Thu, 18 Aug 2016 21:34:44 -0400 X-IBM-Helo: d03dlp01.boulder.ibm.com X-IBM-MailFrom: ego@linux.vnet.ibm.com From: "Gautham R. Shenoy" To: "Rafael J. Wysocki" , Daniel Lezcano , Michael Ellerman , Benjamin Herrenschmidt , Michael Neuling , Paul Mackerras , Vaidyanathan Srinivasan Cc: Anton Blanchard , linux-pm@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, "Gautham R. Shenoy" Subject: [RFC/PATCH 1/2] cpuidle: Allow idle-states to be disabled at start Date: Fri, 19 Aug 2016 03:56:54 +0530 X-Mailer: git-send-email 1.8.3.1 In-Reply-To: References: In-Reply-To: References: X-TM-AS-GCONF: 00 X-Content-Scanned: Fidelis XPS MAILER x-cbid: 16081822-0016-0000-0000-000004755F09 X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00005614; HX=3.00000240; KW=3.00000007; PH=3.00000004; SC=3.00000181; SDB=6.00746583; UDB=6.00352005; IPR=6.00519116; BA=6.00004668; NDR=6.00000001; ZLA=6.00000005; ZF=6.00000009; ZB=6.00000000; ZP=6.00000000; ZH=6.00000000; ZU=6.00000002; MB=3.00012381; XFM=3.00000011; UTC=2016-08-18 22:27:15 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 16081822-0017-0000-0000-00003223BB75 Message-Id: <48afad7788300482c047fc35e70ca8e4bf31a5ac.1471557381.git.ego@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2016-08-18_09:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 suspectscore=0 malwarescore=0 phishscore=0 adultscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1604210000 definitions=main-1608180299 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: "Gautham R. Shenoy" Currently all the idle states registered by a cpu-idle driver are enabled by default. This patch adds a mechanism which allows the driver to hint if an idle-state should start in a disabled state. The cpu-idle core will use this hint to appropriately initialize the usage->disable knob of the CPU device idle state. The state can be enabled at run time by echo'ing a zero to the sysfs "disable" control file. Signed-off-by: Gautham R. Shenoy --- drivers/cpuidle/cpuidle.c | 7 +++++++ include/linux/cpuidle.h | 7 ++++++- 2 files changed, 13 insertions(+), 1 deletion(-) diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c index c73207a..b4debc7 100644 --- a/drivers/cpuidle/cpuidle.c +++ b/drivers/cpuidle/cpuidle.c @@ -439,7 +439,14 @@ static void __cpuidle_unregister_device(struct cpuidle_device *dev) static void __cpuidle_device_init(struct cpuidle_device *dev) { + struct cpuidle_driver *drv = cpuidle_get_cpu_driver(dev); + int i; + memset(dev->states_usage, 0, sizeof(dev->states_usage)); + for (i = 0; i < drv->state_count; i++) { + if (drv->states[i].disable_use_at_start) + dev->states_usage[i].disable = 1; + } dev->last_residency = 0; } diff --git a/include/linux/cpuidle.h b/include/linux/cpuidle.h index bb31373..f3fe855 100644 --- a/include/linux/cpuidle.h +++ b/include/linux/cpuidle.h @@ -44,7 +44,12 @@ struct cpuidle_state { int power_usage; /* in mW */ unsigned int target_residency; /* in US */ bool disabled; /* disabled on all CPUs */ - + /* + * disable_use_at_start: If true, then this idle state will be + * disabled by default. It can be enabled at runtime using the + * per-cpu cpuidle sysfs control file named "disable". + */ + bool disable_use_at_start; int (*enter) (struct cpuidle_device *dev, struct cpuidle_driver *drv, int index); -- 1.9.4