From patchwork Fri Jul 12 07:04:55 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Abhishek Goel X-Patchwork-Id: 11041625 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 3BEFC912 for ; Fri, 12 Jul 2019 07:06:28 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 226E328B5A for ; Fri, 12 Jul 2019 07:06:28 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 13CEF28BB9; Fri, 12 Jul 2019 07:06:28 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 7584028B5A for ; Fri, 12 Jul 2019 07:06:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726094AbfGLHG0 (ORCPT ); Fri, 12 Jul 2019 03:06:26 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:2050 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1725871AbfGLHG0 (ORCPT ); Fri, 12 Jul 2019 03:06:26 -0400 Received: from pps.filterd (m0098417.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id x6C76FJp074996 for ; Fri, 12 Jul 2019 03:06:25 -0400 Received: from e06smtp01.uk.ibm.com (e06smtp01.uk.ibm.com [195.75.94.97]) by mx0a-001b2d01.pphosted.com with ESMTP id 2tpj2my09t-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Fri, 12 Jul 2019 03:06:20 -0400 Received: from localhost by e06smtp01.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Fri, 12 Jul 2019 08:05:34 +0100 Received: from b06cxnps4076.portsmouth.uk.ibm.com (9.149.109.198) by e06smtp01.uk.ibm.com (192.168.101.131) with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted; (version=TLSv1/SSLv3 cipher=AES256-GCM-SHA384 bits=256/256) Fri, 12 Jul 2019 08:05:31 +0100 Received: from d06av21.portsmouth.uk.ibm.com (d06av21.portsmouth.uk.ibm.com [9.149.105.232]) by b06cxnps4076.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id x6C75UQq51314826 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Fri, 12 Jul 2019 07:05:30 GMT Received: from d06av21.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 0A92652051; Fri, 12 Jul 2019 07:05:30 +0000 (GMT) Received: from boston16h.aus.stglabs.ibm.com (unknown [9.3.23.78]) by d06av21.portsmouth.uk.ibm.com (Postfix) with ESMTP id 892795204F; Fri, 12 Jul 2019 07:05:28 +0000 (GMT) From: Abhishek Goel To: linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-pm@vger.kernel.org Cc: npiggin@gmail.com, rjw@rjwysocki.net, daniel.lezcano@linaro.org, mpe@ellerman.id.au, ego@linux.vnet.ibm.com, dja@axtens.net, Abhishek Goel Subject: [PATCH v4 1/3] cpuidle-powernv : forced wakeup for stop states Date: Fri, 12 Jul 2019 02:04:55 -0500 X-Mailer: git-send-email 2.17.1 In-Reply-To: <20190712070457.55242-1-huntbag@linux.vnet.ibm.com> References: <20190712070457.55242-1-huntbag@linux.vnet.ibm.com> X-TM-AS-GCONF: 00 x-cbid: 19071207-4275-0000-0000-0000034C64FD X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 19071207-4276-0000-0000-0000385C6E0C Message-Id: <20190712070457.55242-2-huntbag@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2019-07-12_02:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1907120072 Sender: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Currently, the cpuidle governors determine what idle state a idling CPU should enter into based on heuristics that depend on the idle history on that CPU. Given that no predictive heuristic is perfect, there are cases where the governor predicts a shallow idle state, hoping that the CPU will be busy soon. However, if no new workload is scheduled on that CPU in the near future, the CPU may end up in the shallow state. This is problematic, when the predicted state in the aforementioned scenario is a shallow stop state on a tickless system. As we might get stuck into shallow states for hours, in absence of ticks or interrupts. To address this, We forcefully wakeup the cpu by setting the decrementer. The decrementer is set to a value that corresponds with the residency of the next available state. Thus firing up a timer that will forcefully wakeup the cpu. Few such iterations will essentially train the governor to select a deeper state for that cpu, as the timer here corresponds to the next available cpuidle state residency. Thus, cpu will eventually end up in the deepest possible state. Signed-off-by: Abhishek Goel --- Auto-promotion v1 : started as auto promotion logic for cpuidle states in generic driver v2 : Removed timeout_needed and rebased the code to upstream kernel Forced-wakeup v1 : New patch with name of forced wakeup started v2 : Extending the forced wakeup logic for all states. Setting the decrementer instead of queuing up a hrtimer to implement the logic. v3 : Cleanly handle setting/resetting of decrementer so as to not break irq work v4 : Changed type and name of set/reset decrementer fucntion Handled irq_work_pending in try_set_dec_before_idle arch/powerpc/include/asm/time.h | 2 ++ arch/powerpc/kernel/time.c | 43 +++++++++++++++++++++++++++++++ drivers/cpuidle/cpuidle-powernv.c | 40 ++++++++++++++++++++++++++++ 3 files changed, 85 insertions(+) diff --git a/arch/powerpc/include/asm/time.h b/arch/powerpc/include/asm/time.h index 54f4ec1f9fab..294a472ce161 100644 --- a/arch/powerpc/include/asm/time.h +++ b/arch/powerpc/include/asm/time.h @@ -188,6 +188,8 @@ static inline unsigned long tb_ticks_since(unsigned long tstamp) extern u64 mulhdu(u64, u64); #endif +extern bool try_set_dec_before_idle(u64 timeout); +extern void try_reset_dec_after_idle(void); extern void div128_by_32(u64 dividend_high, u64 dividend_low, unsigned divisor, struct div_result *dr); diff --git a/arch/powerpc/kernel/time.c b/arch/powerpc/kernel/time.c index 694522308cd5..d004c0d8e099 100644 --- a/arch/powerpc/kernel/time.c +++ b/arch/powerpc/kernel/time.c @@ -576,6 +576,49 @@ void arch_irq_work_raise(void) #endif /* CONFIG_IRQ_WORK */ +/* + * This function tries setting decrementer before entering into idle. + * Returns true if we have reprogrammed the decrementer for idle. + * Returns false if the decrementer is unchanged. + */ +bool try_set_dec_before_idle(u64 timeout) +{ + u64 *next_tb = this_cpu_ptr(&decrementers_next_tb); + u64 now = get_tb_or_rtc(); + + if (now + timeout > *next_tb) + return false; + + set_dec(timeout); + if (test_irq_work_pending()) + set_dec(1); + + return true; +} + +/* + * This function gets called if we have set decrementer before + * entering into idle. It tries to reset/restore the decrementer + * to its original value. + */ +void try_reset_dec_after_idle(void) +{ + u64 now; + u64 *next_tb; + + if (test_irq_work_pending()) + return; + + now = get_tb_or_rtc(); + next_tb = this_cpu_ptr(&decrementers_next_tb); + if (now >= *next_tb) + return; + + set_dec(*next_tb - now); + if (test_irq_work_pending()) + set_dec(1); +} + /* * timer_interrupt - gets called when the decrementer overflows, * with interrupts disabled. diff --git a/drivers/cpuidle/cpuidle-powernv.c b/drivers/cpuidle/cpuidle-powernv.c index 84b1ebe212b3..17e20e408ffe 100644 --- a/drivers/cpuidle/cpuidle-powernv.c +++ b/drivers/cpuidle/cpuidle-powernv.c @@ -21,6 +21,7 @@ #include #include #include +#include /* * Expose only those Hardware idle states via the cpuidle framework @@ -46,6 +47,26 @@ static struct stop_psscr_table stop_psscr_table[CPUIDLE_STATE_MAX] __read_mostly static u64 default_snooze_timeout __read_mostly; static bool snooze_timeout_en __read_mostly; +static u64 forced_wakeup_timeout(struct cpuidle_device *dev, + struct cpuidle_driver *drv, + int index) +{ + int i; + + for (i = index + 1; i < drv->state_count; i++) { + struct cpuidle_state *s = &drv->states[i]; + struct cpuidle_state_usage *su = &dev->states_usage[i]; + + if (s->disabled || su->disable) + continue; + + return (s->target_residency + 2 * s->exit_latency) * + tb_ticks_per_usec; + } + + return 0; +} + static u64 get_snooze_timeout(struct cpuidle_device *dev, struct cpuidle_driver *drv, int index) @@ -144,8 +165,27 @@ static int stop_loop(struct cpuidle_device *dev, struct cpuidle_driver *drv, int index) { + u64 timeout_tb; + bool forced_wakeup = false; + + timeout_tb = forced_wakeup_timeout(dev, drv, index); + + /* Ensure that the timeout is at least one microsecond + * greater than current decrement value. Else, we will + * unnecesarily wakeup again within a microsecond if we + * set decrementer with such timeout value. + */ + timeout_tb += 512; + + if (timeout_tb) + forced_wakeup = try_set_dec_before_idle(timeout_tb); + power9_idle_type(stop_psscr_table[index].val, stop_psscr_table[index].mask); + + if (forced_wakeup) + try_reset_dec_after_idle(); + return index; } From patchwork Fri Jul 12 07:04:56 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Abhishek Goel X-Patchwork-Id: 11041623 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id B068113A4 for ; Fri, 12 Jul 2019 07:05:53 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 9E3A328A11 for ; Fri, 12 Jul 2019 07:05:53 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 8E09128AD3; Fri, 12 Jul 2019 07:05:53 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 2E28228A11 for ; Fri, 12 Jul 2019 07:05:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726188AbfGLHFw (ORCPT ); Fri, 12 Jul 2019 03:05:52 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:46114 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725866AbfGLHFw (ORCPT ); Fri, 12 Jul 2019 03:05:52 -0400 Received: from pps.filterd (m0098399.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id x6C732NJ140862 for ; Fri, 12 Jul 2019 03:05:51 -0400 Received: from e06smtp04.uk.ibm.com (e06smtp04.uk.ibm.com [195.75.94.100]) by mx0a-001b2d01.pphosted.com with ESMTP id 2tpn4s0xdf-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Fri, 12 Jul 2019 03:05:50 -0400 Received: from localhost by e06smtp04.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Fri, 12 Jul 2019 08:05:48 +0100 Received: from b06cxnps4075.portsmouth.uk.ibm.com (9.149.109.197) by e06smtp04.uk.ibm.com (192.168.101.134) with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted; (version=TLSv1/SSLv3 cipher=AES256-GCM-SHA384 bits=256/256) Fri, 12 Jul 2019 08:05:44 +0100 Received: from d06av21.portsmouth.uk.ibm.com (d06av21.portsmouth.uk.ibm.com [9.149.105.232]) by b06cxnps4075.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id x6C75hMS36175986 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Fri, 12 Jul 2019 07:05:43 GMT Received: from d06av21.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id C704252069; Fri, 12 Jul 2019 07:05:43 +0000 (GMT) Received: from boston16h.aus.stglabs.ibm.com (unknown [9.3.23.78]) by d06av21.portsmouth.uk.ibm.com (Postfix) with ESMTP id 5C2A952054; Fri, 12 Jul 2019 07:05:42 +0000 (GMT) From: Abhishek Goel To: linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-pm@vger.kernel.org Cc: npiggin@gmail.com, rjw@rjwysocki.net, daniel.lezcano@linaro.org, mpe@ellerman.id.au, ego@linux.vnet.ibm.com, dja@axtens.net, Abhishek Goel Subject: [RFC v4 2/3] cpuidle : Add callback whenever a state usage is enabled/disabled Date: Fri, 12 Jul 2019 02:04:56 -0500 X-Mailer: git-send-email 2.17.1 In-Reply-To: <20190712070457.55242-1-huntbag@linux.vnet.ibm.com> References: <20190712070457.55242-1-huntbag@linux.vnet.ibm.com> X-TM-AS-GCONF: 00 x-cbid: 19071207-0016-0000-0000-00000291FA78 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 19071207-0017-0000-0000-000032EFBD4A Message-Id: <20190712070457.55242-3-huntbag@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2019-07-12_02:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=838 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1907120072 Sender: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP To force wakeup a cpu, we need to compute the timeout in the fast idle path as a state may be enabled or disabled but there did not exist a feedback to driver when a state is enabled or disabled. This patch adds a callback whenever a state_usage records a store for disable attribute. Signed-off-by: Abhishek Goel --- drivers/cpuidle/sysfs.c | 15 ++++++++++++++- include/linux/cpuidle.h | 4 ++++ 2 files changed, 18 insertions(+), 1 deletion(-) diff --git a/drivers/cpuidle/sysfs.c b/drivers/cpuidle/sysfs.c index eb20adb5de23..141671a53967 100644 --- a/drivers/cpuidle/sysfs.c +++ b/drivers/cpuidle/sysfs.c @@ -415,8 +415,21 @@ static ssize_t cpuidle_state_store(struct kobject *kobj, struct attribute *attr, struct cpuidle_state_usage *state_usage = kobj_to_state_usage(kobj); struct cpuidle_state_attr *cattr = attr_to_stateattr(attr); - if (cattr->store) + if (cattr->store) { ret = cattr->store(state, state_usage, buf, size); + if (ret == size && + strncmp(cattr->attr.name, "disable", + strlen("disable"))) { + struct kobject *cpuidle_kobj = kobj->parent; + struct cpuidle_device *dev = + to_cpuidle_device(cpuidle_kobj); + struct cpuidle_driver *drv = + cpuidle_get_cpu_driver(dev); + + if (drv->disable_callback) + drv->disable_callback(dev, drv); + } + } return ret; } diff --git a/include/linux/cpuidle.h b/include/linux/cpuidle.h index bb9a0db89f1a..8a0e54bd0d5d 100644 --- a/include/linux/cpuidle.h +++ b/include/linux/cpuidle.h @@ -119,6 +119,10 @@ struct cpuidle_driver { /* the driver handles the cpus in cpumask */ struct cpumask *cpumask; + + void (*disable_callback)(struct cpuidle_device *dev, + struct cpuidle_driver *drv); + }; #ifdef CONFIG_CPU_IDLE From patchwork Fri Jul 12 07:04:57 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Abhishek Goel X-Patchwork-Id: 11041627 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 184AC912 for ; Fri, 12 Jul 2019 07:06:42 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 071E228B5A for ; Fri, 12 Jul 2019 07:06:42 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id EE90728BB9; Fri, 12 Jul 2019 07:06:41 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 7D27228B5A for ; Fri, 12 Jul 2019 07:06:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726078AbfGLHGl (ORCPT ); Fri, 12 Jul 2019 03:06:41 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:15058 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1725871AbfGLHGk (ORCPT ); Fri, 12 Jul 2019 03:06:40 -0400 Received: from pps.filterd (m0098417.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id x6C76Fxt075053 for ; Fri, 12 Jul 2019 03:06:39 -0400 Received: from e06smtp04.uk.ibm.com (e06smtp04.uk.ibm.com [195.75.94.100]) by mx0a-001b2d01.pphosted.com with ESMTP id 2tpj2my0g7-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Fri, 12 Jul 2019 03:06:32 -0400 Received: from localhost by e06smtp04.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Fri, 12 Jul 2019 08:05:55 +0100 Received: from b06avi18878370.portsmouth.uk.ibm.com (9.149.26.194) by e06smtp04.uk.ibm.com (192.168.101.134) with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted; (version=TLSv1/SSLv3 cipher=AES256-GCM-SHA384 bits=256/256) Fri, 12 Jul 2019 08:05:53 +0100 Received: from d06av21.portsmouth.uk.ibm.com (d06av21.portsmouth.uk.ibm.com [9.149.105.232]) by b06avi18878370.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id x6C75q0p36700450 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Fri, 12 Jul 2019 07:05:52 GMT Received: from d06av21.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 3B7805204E; Fri, 12 Jul 2019 07:05:52 +0000 (GMT) Received: from boston16h.aus.stglabs.ibm.com (unknown [9.3.23.78]) by d06av21.portsmouth.uk.ibm.com (Postfix) with ESMTP id B98D952051; Fri, 12 Jul 2019 07:05:50 +0000 (GMT) From: Abhishek Goel To: linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-pm@vger.kernel.org Cc: npiggin@gmail.com, rjw@rjwysocki.net, daniel.lezcano@linaro.org, mpe@ellerman.id.au, ego@linux.vnet.ibm.com, dja@axtens.net, Abhishek Goel Subject: [RFC v4 3/3] cpuidle-powernv : Recompute the idle-state timeouts when state usage is enabled/disabled Date: Fri, 12 Jul 2019 02:04:57 -0500 X-Mailer: git-send-email 2.17.1 In-Reply-To: <20190712070457.55242-1-huntbag@linux.vnet.ibm.com> References: <20190712070457.55242-1-huntbag@linux.vnet.ibm.com> X-TM-AS-GCONF: 00 x-cbid: 19071207-0016-0000-0000-00000291FA7D X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 19071207-0017-0000-0000-000032EFBD50 Message-Id: <20190712070457.55242-4-huntbag@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2019-07-12_02:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1907120072 Sender: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP The disable callback can be used to compute timeout for other states whenever a state is enabled or disabled. We store the computed timeout in "timeout" defined in cpuidle state strucure. So, we compute timeout only when some state is enabled or disabled and not every time in the fast idle path. We also use the computed timeout to get timeout for snooze, thus getting rid of get_snooze_timeout for snooze loop. Signed-off-by: Abhishek Goel --- drivers/cpuidle/cpuidle-powernv.c | 35 +++++++++++-------------------- include/linux/cpuidle.h | 1 + 2 files changed, 13 insertions(+), 23 deletions(-) diff --git a/drivers/cpuidle/cpuidle-powernv.c b/drivers/cpuidle/cpuidle-powernv.c index 17e20e408ffe..29add322d0c4 100644 --- a/drivers/cpuidle/cpuidle-powernv.c +++ b/drivers/cpuidle/cpuidle-powernv.c @@ -45,7 +45,6 @@ struct stop_psscr_table { static struct stop_psscr_table stop_psscr_table[CPUIDLE_STATE_MAX] __read_mostly; static u64 default_snooze_timeout __read_mostly; -static bool snooze_timeout_en __read_mostly; static u64 forced_wakeup_timeout(struct cpuidle_device *dev, struct cpuidle_driver *drv, @@ -67,26 +66,13 @@ static u64 forced_wakeup_timeout(struct cpuidle_device *dev, return 0; } -static u64 get_snooze_timeout(struct cpuidle_device *dev, - struct cpuidle_driver *drv, - int index) +static void pnv_disable_callback(struct cpuidle_device *dev, + struct cpuidle_driver *drv) { int i; - if (unlikely(!snooze_timeout_en)) - return default_snooze_timeout; - - for (i = index + 1; i < drv->state_count; i++) { - struct cpuidle_state *s = &drv->states[i]; - struct cpuidle_state_usage *su = &dev->states_usage[i]; - - if (s->disabled || su->disable) - continue; - - return s->target_residency * tb_ticks_per_usec; - } - - return default_snooze_timeout; + for (i = 0; i < drv->state_count; i++) + drv->states[i].timeout = forced_wakeup_timeout(dev, drv, i); } static int snooze_loop(struct cpuidle_device *dev, @@ -94,16 +80,20 @@ static int snooze_loop(struct cpuidle_device *dev, int index) { u64 snooze_exit_time; + u64 snooze_timeout = drv->states[index].timeout; + + if (!snooze_timeout) + snooze_timeout = default_snooze_timeout; set_thread_flag(TIF_POLLING_NRFLAG); local_irq_enable(); - snooze_exit_time = get_tb() + get_snooze_timeout(dev, drv, index); + snooze_exit_time = get_tb() + snooze_timeout; ppc64_runlatch_off(); HMT_very_low(); while (!need_resched()) { - if (likely(snooze_timeout_en) && get_tb() > snooze_exit_time) { + if (get_tb() > snooze_exit_time) { /* * Task has not woken up but we are exiting the polling * loop anyway. Require a barrier after polling is @@ -168,7 +158,7 @@ static int stop_loop(struct cpuidle_device *dev, u64 timeout_tb; bool forced_wakeup = false; - timeout_tb = forced_wakeup_timeout(dev, drv, index); + timeout_tb = drv->states[index].timeout; /* Ensure that the timeout is at least one microsecond * greater than current decrement value. Else, we will @@ -263,6 +253,7 @@ static int powernv_cpuidle_driver_init(void) */ drv->cpumask = (struct cpumask *)cpu_present_mask; + drv->disable_callback = pnv_disable_callback; return 0; } @@ -422,8 +413,6 @@ static int powernv_idle_probe(void) /* Device tree can indicate more idle states */ max_idle_state = powernv_add_idle_states(); default_snooze_timeout = TICK_USEC * tb_ticks_per_usec; - if (max_idle_state > 1) - snooze_timeout_en = true; } else return -ENODEV; diff --git a/include/linux/cpuidle.h b/include/linux/cpuidle.h index 8a0e54bd0d5d..31662b657b9c 100644 --- a/include/linux/cpuidle.h +++ b/include/linux/cpuidle.h @@ -50,6 +50,7 @@ struct cpuidle_state { int power_usage; /* in mW */ unsigned int target_residency; /* in US */ bool disabled; /* disabled on all CPUs */ + unsigned long long timeout; /* timeout for exiting out of a state */ int (*enter) (struct cpuidle_device *dev, struct cpuidle_driver *drv,