From patchwork Fri Oct 23 15:35:19 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Rafael J. Wysocki" X-Patchwork-Id: 286729 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id CAB22C4363A for ; Fri, 23 Oct 2020 15:36:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7852D221F9 for ; Fri, 23 Oct 2020 15:36:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750910AbgJWPgu (ORCPT ); Fri, 23 Oct 2020 11:36:50 -0400 Received: from cloudserver094114.home.pl ([79.96.170.134]:52656 "EHLO cloudserver094114.home.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750889AbgJWPgt (ORCPT ); Fri, 23 Oct 2020 11:36:49 -0400 Received: from 89-64-88-190.dynamic.chello.pl (89.64.88.190) (HELO kreacher.localnet) by serwer1319399.home.pl (79.96.170.134) with SMTP (IdeaSmtpServer 0.83.491) id d99488cc2732ed08; Fri, 23 Oct 2020 17:36:47 +0200 From: "Rafael J. Wysocki" To: Linux PM , Viresh Kumar Cc: LKML , Srinivas Pandruvada , Zhang Rui Subject: [PATCH v2 1/4] cpufreq: Introduce CPUFREQ_NEED_UPDATE_LIMITS driver flag Date: Fri, 23 Oct 2020 17:35:19 +0200 Message-ID: <1673796.UrKzctInAk@kreacher> In-Reply-To: <2183878.gTFULuzKx9@kreacher> References: <2183878.gTFULuzKx9@kreacher> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org From: Rafael J. Wysocki Generally, a cpufreq driver may need to update some internal upper and lower frequency boundaries on policy max and min changes, respectively, but currently this does not work if the target frequency does not change along with the policy limit. Namely, if the target frequency does not change along with the policy min or max, the "target_freq == policy->cur" check in __cpufreq_driver_target() prevents driver callbacks from being invoked and they do not even have a chance to update the corresponding internal boundary. This particularly affects the "powersave" and "performance" governors that always set the target frequency to one of the policy limits and it never changes when the other limit is updated. To allow cpufreq the drivers needing to update internal frequency boundaries on policy limits changes to avoid this issue, introduce a new driver flag, CPUFREQ_NEED_UPDATE_LIMITS, that (when set) will neutralize the check mentioned above. Signed-off-by: Rafael J. Wysocki Acked-by: Viresh Kumar --- New patch in v2. --- drivers/cpufreq/cpufreq.c | 3 ++- include/linux/cpufreq.h | 10 +++++++++- 2 files changed, 11 insertions(+), 2 deletions(-) Index: linux-pm/include/linux/cpufreq.h =================================================================== --- linux-pm.orig/include/linux/cpufreq.h +++ linux-pm/include/linux/cpufreq.h @@ -297,7 +297,7 @@ __ATTR(_name, 0644, show_##_name, store_ struct cpufreq_driver { char name[CPUFREQ_NAME_LEN]; - u8 flags; + u16 flags; void *driver_data; /* needed by all drivers */ @@ -417,6 +417,14 @@ struct cpufreq_driver { */ #define CPUFREQ_IS_COOLING_DEV BIT(7) +/* + * Set by drivers that need to update internale upper and lower boundaries along + * with the target frequency and so the core and governors should also invoke + * the diver if the target frequency does not change, but the policy min or max + * may have changed. + */ +#define CPUFREQ_NEED_UPDATE_LIMITS BIT(8) + int cpufreq_register_driver(struct cpufreq_driver *driver_data); int cpufreq_unregister_driver(struct cpufreq_driver *driver_data); Index: linux-pm/drivers/cpufreq/cpufreq.c =================================================================== --- linux-pm.orig/drivers/cpufreq/cpufreq.c +++ linux-pm/drivers/cpufreq/cpufreq.c @@ -2191,7 +2191,8 @@ int __cpufreq_driver_target(struct cpufr * exactly same freq is called again and so we can save on few function * calls. */ - if (target_freq == policy->cur) + if (target_freq == policy->cur && + !(cpufreq_driver->flags & CPUFREQ_NEED_UPDATE_LIMITS)) return 0; if (cpufreq_driver->target) From patchwork Fri Oct 23 15:35:32 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Rafael J. Wysocki" X-Patchwork-Id: 286730 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 29360C4363A for ; Fri, 23 Oct 2020 15:36:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C85D920E65 for ; Fri, 23 Oct 2020 15:36:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750902AbgJWPgt (ORCPT ); Fri, 23 Oct 2020 11:36:49 -0400 Received: from cloudserver094114.home.pl ([79.96.170.134]:48992 "EHLO cloudserver094114.home.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750890AbgJWPgs (ORCPT ); Fri, 23 Oct 2020 11:36:48 -0400 Received: from 89-64-88-190.dynamic.chello.pl (89.64.88.190) (HELO kreacher.localnet) by serwer1319399.home.pl (79.96.170.134) with SMTP (IdeaSmtpServer 0.83.491) id fd4a279f45e740d9; Fri, 23 Oct 2020 17:36:46 +0200 From: "Rafael J. Wysocki" To: Linux PM , Viresh Kumar Cc: LKML , Srinivas Pandruvada , Zhang Rui Subject: [PATCH v2 2/4] cpufreq: intel_pstate: Avoid missing HWP max updates in passive mode Date: Fri, 23 Oct 2020 17:35:32 +0200 Message-ID: <3212190.yEXfVNHMLB@kreacher> In-Reply-To: <2183878.gTFULuzKx9@kreacher> References: <2183878.gTFULuzKx9@kreacher> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org From: Rafael J. Wysocki If the cpufreq policy max limit is changed when intel_pstate operates in the passive mode with HWP enabled and the "powersave" governor is used on top of it, the HWP max limit is not updated as appropriate. Namely, in the "powersave" governor case, the target P-state is always equal to the policy min limit, so if the latter does not change, intel_cpufreq_adjust_hwp() is not invoked to update the HWP Request MSR due to the "target_pstate != old_pstate" check in intel_cpufreq_update_pstate(), so the HWP max limit is not updated as a result. Also, if the CPUFREQ_NEED_UPDATE_LIMITS flag is not set for the driver and the target frequency does not change along with the policy max limit, the "target_freq == policy->cur" check in __cpufreq_driver_target() prevents the driver's ->target() callback from being invoked at all, so the HWP max limit is not updated. To prevent that occurring, set the CPUFREQ_NEED_UPDATE_LIMITS flag in the intel_cpufreq driver structure if HWP is enabled and modify intel_cpufreq_update_pstate() to do the "target_pstate != old_pstate" check only in the non-HWP case and let intel_cpufreq_adjust_hwp() always run in the HWP case (it will update HWP Request only if the cached value of the register is different from the new one including the limits, so if neither the target P-state value nor the max limit changes, the register write will still be avoided). Fixes: f6ebbcf08f37 ("cpufreq: intel_pstate: Implement passive mode with HWP enabled") Reported-by: Zhang Rui Cc: 5.9+ # 5.9+ Signed-off-by: Rafael J. Wysocki Acked-by: Viresh Kumar Tested-by: Zhang Rui --- The v2 is just the intel_pstate changes (without the core changes) and setting the new flag. --- drivers/cpufreq/intel_pstate.c | 13 ++++++------- 1 file changed, 6 insertions(+), 7 deletions(-) Index: linux-pm/drivers/cpufreq/intel_pstate.c =================================================================== --- linux-pm.orig/drivers/cpufreq/intel_pstate.c +++ linux-pm/drivers/cpufreq/intel_pstate.c @@ -2550,14 +2550,12 @@ static int intel_cpufreq_update_pstate(s int old_pstate = cpu->pstate.current_pstate; target_pstate = intel_pstate_prepare_request(cpu, target_pstate); - if (target_pstate != old_pstate) { + if (hwp_active) { + intel_cpufreq_adjust_hwp(cpu, target_pstate, fast_switch); + cpu->pstate.current_pstate = target_pstate; + } else if (target_pstate != old_pstate) { + intel_cpufreq_adjust_perf_ctl(cpu, target_pstate, fast_switch); cpu->pstate.current_pstate = target_pstate; - if (hwp_active) - intel_cpufreq_adjust_hwp(cpu, target_pstate, - fast_switch); - else - intel_cpufreq_adjust_perf_ctl(cpu, target_pstate, - fast_switch); } intel_cpufreq_trace(cpu, fast_switch ? INTEL_PSTATE_TRACE_FAST_SWITCH : @@ -3014,6 +3012,7 @@ static int __init intel_pstate_init(void hwp_mode_bdw = id->driver_data; intel_pstate.attr = hwp_cpufreq_attrs; intel_cpufreq.attr = hwp_cpufreq_attrs; + intel_cpufreq.flags |= CPUFREQ_NEED_UPDATE_LIMITS; if (!default_driver) default_driver = &intel_pstate; From patchwork Fri Oct 23 15:36:05 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Rafael J. Wysocki" X-Patchwork-Id: 286731 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id EFB62C4363A for ; Fri, 23 Oct 2020 15:36:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8B7E521D47 for ; Fri, 23 Oct 2020 15:36:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S465926AbgJWPgk (ORCPT ); Fri, 23 Oct 2020 11:36:40 -0400 Received: from cloudserver094114.home.pl ([79.96.170.134]:49018 "EHLO cloudserver094114.home.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S462626AbgJWPgk (ORCPT ); Fri, 23 Oct 2020 11:36:40 -0400 Received: from 89-64-88-190.dynamic.chello.pl (89.64.88.190) (HELO kreacher.localnet) by serwer1319399.home.pl (79.96.170.134) with SMTP (IdeaSmtpServer 0.83.491) id caedd8ec897095a1; Fri, 23 Oct 2020 17:36:38 +0200 From: "Rafael J. Wysocki" To: Linux PM , Viresh Kumar Cc: LKML , Srinivas Pandruvada , Zhang Rui Subject: [PATCH v2 4/4] cpufreq: schedutil: Always call drvier if need_freq_update is set Date: Fri, 23 Oct 2020 17:36:05 +0200 Message-ID: <1905098.zDJocX6404@kreacher> In-Reply-To: <2183878.gTFULuzKx9@kreacher> References: <2183878.gTFULuzKx9@kreacher> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org From: Rafael J. Wysocki Because sugov_update_next_freq() may skip a frequency update even if the need_freq_update flag has been set for the policy at hand, policy limits updates may not take effect as expected. For example, if the intel_pstate driver operates in the passive mode with HWP enabled, it needs to update the HWP min and max limits when the policy min and max limits change, respectively, but that may not happen if the target frequency does not change along with the limit at hand. In particular, if the policy min is changed first, causing the target frequency to be adjusted to it, and the policy max limit is changed later to the same value, the HWP max limit will not be updated to follow it as expected, because the target frequency is still equal to the policy min limit and it will not change until that limit is updated. To address this issue, modify get_next_freq() to clear need_freq_update only if the CPUFREQ_NEED_UPDATE_LIMITS flag is not set for the cpufreq driver in use (and it should be set for all potentially affected drivers) and make sugov_update_next_freq() check need_freq_update and continue when it is set regardless of whether or not the new target frequency is equal to the old one. Fixes: f6ebbcf08f37 ("cpufreq: intel_pstate: Implement passive mode with HWP enabled") Reported-by: Zhang Rui Cc: 5.9+ # 5.9+ Signed-off-by: Rafael J. Wysocki Tested-by: Zhang Rui Acked-by: Viresh Kumar --- New patch in v2. --- kernel/sched/cpufreq_schedutil.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) Index: linux-pm/kernel/sched/cpufreq_schedutil.c =================================================================== --- linux-pm.orig/kernel/sched/cpufreq_schedutil.c +++ linux-pm/kernel/sched/cpufreq_schedutil.c @@ -102,11 +102,12 @@ static bool sugov_should_update_freq(str static bool sugov_update_next_freq(struct sugov_policy *sg_policy, u64 time, unsigned int next_freq) { - if (sg_policy->next_freq == next_freq) + if (sg_policy->next_freq == next_freq && !sg_policy->need_freq_update) return false; sg_policy->next_freq = next_freq; sg_policy->last_freq_update_time = time; + sg_policy->need_freq_update = false; return true; } @@ -164,7 +165,10 @@ static unsigned int get_next_freq(struct if (freq == sg_policy->cached_raw_freq && !sg_policy->need_freq_update) return sg_policy->next_freq; - sg_policy->need_freq_update = false; + if (sg_policy->need_freq_update) + sg_policy->need_freq_update = + cpufreq_driver_test_flags(CPUFREQ_NEED_UPDATE_LIMITS); + sg_policy->cached_raw_freq = freq; return cpufreq_driver_resolve_freq(policy, freq); }