From patchwork Wed Sep 4 10:41:23 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Rafael J. Wysocki" X-Patchwork-Id: 11129867 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 599B813B1 for ; Wed, 4 Sep 2019 10:41:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 30BFE2339D for ; Wed, 4 Sep 2019 10:41:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726304AbfIDKl1 (ORCPT ); Wed, 4 Sep 2019 06:41:27 -0400 Received: from cloudserver094114.home.pl ([79.96.170.134]:55333 "EHLO cloudserver094114.home.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725966AbfIDKl1 (ORCPT ); Wed, 4 Sep 2019 06:41:27 -0400 Received: from 79.184.255.97.ipv4.supernova.orange.pl (79.184.255.97) (HELO kreacher.localnet) by serwer1319399.home.pl (79.96.170.134) with SMTP (IdeaSmtpServer 0.83.292) id 9116fb2f2bcf1c8b; Wed, 4 Sep 2019 12:41:23 +0200 From: "Rafael J. Wysocki" To: Linux PM Cc: Peter Zijlstra , Daniel Lezcano Subject: [RFC][PATCH] cpuidle: Consolidate disabled state checks Date: Wed, 04 Sep 2019 12:41:23 +0200 Message-ID: <2136682.Ujdk25Y4fk@kreacher> MIME-Version: 1.0 Sender: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org From: Rafael J. Wysocki There are two reasons why CPU idle states may be disabled: either because the driver has disabled them or because they have been disabled by user space via sysfs. In the former case, the state's "disabled" flag is set once during the initialization of the driver and it is never cleared later (it is read-only effectively). In the latter case, the "disable" field of the given state's cpuidle_state_usage struct is set and it may be changed via sysfs. Thus checking whether or not an idle state has been disabled involves reading these two flags every time. In order to avoid the additional check of the state's "disabled" flag (which is effectively read-only anyway), use the value of it at the init time to set a (new) flag in the "disable" field of that state's cpuidle_state_usage structure and use the sysfs interface to manipulate another (new) flag in it. This way the state is disabled whenever the "disable" field of its cpuidle_state_usage structure is nonzero, whatever the reason, and it is the only place to look into to check whether or not the state has been disabled. Signed-off-by: Rafael J. Wysocki Acked-by: Daniel Lezcano --- I have not tested this yet, hence RFC, so it is mainly for feedback. --- drivers/cpuidle/cpuidle-powernv.c | 7 +----- drivers/cpuidle/cpuidle.c | 24 +++++++++++---------- drivers/cpuidle/governors/ladder.c | 4 --- drivers/cpuidle/governors/menu.c | 8 ++----- drivers/cpuidle/governors/teo.c | 5 +--- drivers/cpuidle/sysfs.c | 42 +++++++++++++++++++------------------ include/linux/cpuidle.h | 3 ++ 7 files changed, 46 insertions(+), 47 deletions(-) Index: linux-pm/drivers/cpuidle/cpuidle.c =================================================================== --- linux-pm.orig/drivers/cpuidle/cpuidle.c +++ linux-pm/drivers/cpuidle/cpuidle.c @@ -84,12 +84,12 @@ static int find_deepest_state(struct cpu for (i = 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 || s->exit_latency <= latency_req - || s->exit_latency > max_latency - || (s->flags & forbidden_flags) - || (s2idle && !s->enter_s2idle)) + if (dev->states_usage[i].disable || + s->exit_latency <= latency_req || + s->exit_latency > max_latency || + (s->flags & forbidden_flags) || + (s2idle && !s->enter_s2idle)) continue; latency_req = s->exit_latency; @@ -265,8 +265,7 @@ int cpuidle_enter_state(struct cpuidle_d if (diff < drv->states[entered_state].target_residency) { for (i = entered_state - 1; i >= 0; i--) { - if (drv->states[i].disabled || - dev->states_usage[i].disable) + if (dev->states_usage[i].disable) continue; /* Shallower states are enabled, so update. */ @@ -275,8 +274,7 @@ int cpuidle_enter_state(struct cpuidle_d } } else if (diff > delay) { for (i = entered_state + 1; i < drv->state_count; i++) { - if (drv->states[i].disabled || - dev->states_usage[i].disable) + if (dev->states_usage[i].disable) continue; /* @@ -380,7 +378,7 @@ u64 cpuidle_poll_time(struct cpuidle_dri limit_ns = TICK_NSEC; for (i = 1; i < drv->state_count; i++) { - if (drv->states[i].disabled || dev->states_usage[i].disable) + if (dev->states_usage[i].disable) continue; limit_ns = (u64)drv->states[i].target_residency * NSEC_PER_USEC; @@ -567,12 +565,16 @@ static void __cpuidle_device_init(struct */ static int __cpuidle_register_device(struct cpuidle_device *dev) { - int ret; struct cpuidle_driver *drv = cpuidle_get_cpu_driver(dev); + int i, ret; if (!try_module_get(drv->owner)) return -EINVAL; + for (i = 0; i < drv->state_count; i++) + if (drv->states[i].disabled) + dev->states_usage[i].disable |= CPUIDLE_STATE_DISABLED_BY_DRIVER; + per_cpu(cpuidle_devices, dev->cpu) = dev; list_add(&dev->device_list, &cpuidle_detected_devices); Index: linux-pm/drivers/cpuidle/sysfs.c =================================================================== --- linux-pm.orig/drivers/cpuidle/sysfs.c +++ linux-pm/drivers/cpuidle/sysfs.c @@ -255,25 +255,6 @@ static ssize_t show_state_##_name(struct return sprintf(buf, "%u\n", state->_name);\ } -#define define_store_state_ull_function(_name) \ -static ssize_t store_state_##_name(struct cpuidle_state *state, \ - struct cpuidle_state_usage *state_usage, \ - const char *buf, size_t size) \ -{ \ - unsigned long long value; \ - int err; \ - if (!capable(CAP_SYS_ADMIN)) \ - return -EPERM; \ - err = kstrtoull(buf, 0, &value); \ - if (err) \ - return err; \ - if (value) \ - state_usage->_name = 1; \ - else \ - state_usage->_name = 0; \ - return size; \ -} - #define define_show_state_ull_function(_name) \ static ssize_t show_state_##_name(struct cpuidle_state *state, \ struct cpuidle_state_usage *state_usage, \ @@ -300,10 +281,31 @@ define_show_state_ull_function(time) define_show_state_str_function(name) define_show_state_str_function(desc) define_show_state_ull_function(disable) -define_store_state_ull_function(disable) define_show_state_ull_function(above) define_show_state_ull_function(below) +static ssize_t store_state_disable(struct cpuidle_state *state, + struct cpuidle_state_usage *state_usage, + const char *buf, size_t size) +{ + unsigned int value; + int err; + + if (!capable(CAP_SYS_ADMIN)) + return -EPERM; + + err = kstrtouint(buf, 0, &value); + if (err) + return err; + + if (value) + state_usage->disable |= CPUIDLE_STATE_DISABLED_BY_USER; + else + state_usage->disable &= ~CPUIDLE_STATE_DISABLED_BY_USER; + + return size; +} + define_one_state_ro(name, show_state_name); define_one_state_ro(desc, show_state_desc); define_one_state_ro(latency, show_state_exit_latency); Index: linux-pm/include/linux/cpuidle.h =================================================================== --- linux-pm.orig/include/linux/cpuidle.h +++ linux-pm/include/linux/cpuidle.h @@ -29,6 +29,9 @@ struct cpuidle_driver; * CPUIDLE DEVICE INTERFACE * ****************************/ +#define CPUIDLE_STATE_DISABLED_BY_USER BIT(0) +#define CPUIDLE_STATE_DISABLED_BY_DRIVER BIT(1) + struct cpuidle_state_usage { unsigned long long disable; unsigned long long usage; Index: linux-pm/drivers/cpuidle/governors/menu.c =================================================================== --- linux-pm.orig/drivers/cpuidle/governors/menu.c +++ linux-pm/drivers/cpuidle/governors/menu.c @@ -298,7 +298,7 @@ static int menu_select(struct cpuidle_dr if (unlikely(drv->state_count <= 1 || latency_req == 0) || ((data->next_timer_us < drv->states[1].target_residency || latency_req < drv->states[1].exit_latency) && - !drv->states[0].disabled && !dev->states_usage[0].disable)) { + !dev->states_usage[0].disable)) { /* * In this case state[0] will be used no matter what, so return * it right away and keep the tick running if state[0] is a @@ -349,9 +349,8 @@ static int menu_select(struct cpuidle_dr idx = -1; for (i = 0; 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) + if (dev->states_usage[i]->disable) continue; if (idx == -1) @@ -422,8 +421,7 @@ static int menu_select(struct cpuidle_dr * tick, so try to correct that. */ for (i = idx - 1; i >= 0; i--) { - if (drv->states[i].disabled || - dev->states_usage[i].disable) + if (dev->states_usage[i].disable) continue; idx = i; Index: linux-pm/drivers/cpuidle/governors/teo.c =================================================================== --- linux-pm.orig/drivers/cpuidle/governors/teo.c +++ linux-pm/drivers/cpuidle/governors/teo.c @@ -212,7 +212,7 @@ static int teo_find_shallower_state(stru int i; for (i = state_idx - 1; i >= 0; i--) { - if (drv->states[i].disabled || dev->states_usage[i].disable) + if (dev->states_usage[i].disable) continue; state_idx = i; @@ -254,9 +254,8 @@ static int teo_select(struct cpuidle_dri for (i = 0; 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) { + if (dev->states_usage[i].disable) { /* * If the "early hits" metric of a disabled state is * greater than the current maximum, it should be taken Index: linux-pm/drivers/cpuidle/governors/ladder.c =================================================================== --- linux-pm.orig/drivers/cpuidle/governors/ladder.c +++ linux-pm/drivers/cpuidle/governors/ladder.c @@ -84,7 +84,6 @@ static int ladder_select_state(struct cp /* consider promotion */ if (last_idx < drv->state_count - 1 && - !drv->states[last_idx + 1].disabled && !dev->states_usage[last_idx + 1].disable && last_residency > last_state->threshold.promotion_time && drv->states[last_idx + 1].exit_latency <= latency_req) { @@ -98,8 +97,7 @@ static int ladder_select_state(struct cp /* consider demotion */ if (last_idx > first_idx && - (drv->states[last_idx].disabled || - dev->states_usage[last_idx].disable || + (dev->states_usage[last_idx].disable || drv->states[last_idx].exit_latency > latency_req)) { int i; Index: linux-pm/drivers/cpuidle/cpuidle-powernv.c =================================================================== --- linux-pm.orig/drivers/cpuidle/cpuidle-powernv.c +++ linux-pm/drivers/cpuidle/cpuidle-powernv.c @@ -56,13 +56,10 @@ static u64 get_snooze_timeout(struct cpu 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) + if (dev->states_usage[i].disable) continue; - return s->target_residency * tb_ticks_per_usec; + return drv->states[i].target_residency * tb_ticks_per_usec; } return default_snooze_timeout;