From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755839AbaCYRvf (ORCPT ); Tue, 25 Mar 2014 13:51:35 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:55712 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754646AbaCYRTD (ORCPT ); Tue, 25 Mar 2014 13:19:03 -0400 From: Kamal Mostafa To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Lan Tianyu , "Rafael J. Wysocki" , Kamal Mostafa Subject: [PATCH 3.8 68/81] ACPI / processor: Rework processor throttling with work_on_cpu() Date: Tue, 25 Mar 2014 10:16:21 -0700 Message-Id: <1395767794-5012-69-git-send-email-kamal@canonical.com> X-Mailer: git-send-email 1.8.3.2 In-Reply-To: <1395767794-5012-1-git-send-email-kamal@canonical.com> References: <1395767794-5012-1-git-send-email-kamal@canonical.com> X-Extended-Stable: 3.8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.8.13.20 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Lan Tianyu commit f3ca4164529b875374c410193bbbac0ee960895f upstream. acpi_processor_set_throttling() uses set_cpus_allowed_ptr() to make sure that the (struct acpi_processor)->acpi_processor_set_throttling() callback will run on the right CPU. However, the function may be called from a worker thread already bound to a different CPU in which case that won't work. Make acpi_processor_set_throttling() use work_on_cpu() as appropriate instead of abusing set_cpus_allowed_ptr(). Reported-and-tested-by: Jiri Olsa Signed-off-by: Lan Tianyu [rjw: Changelog] Signed-off-by: Rafael J. Wysocki Signed-off-by: Kamal Mostafa --- drivers/acpi/processor_throttling.c | 69 +++++++++++++++++-------------------- 1 file changed, 32 insertions(+), 37 deletions(-) diff --git a/drivers/acpi/processor_throttling.c b/drivers/acpi/processor_throttling.c index 1d02b7b..c653cc2 100644 --- a/drivers/acpi/processor_throttling.c +++ b/drivers/acpi/processor_throttling.c @@ -59,6 +59,12 @@ struct throttling_tstate { int target_state; /* target T-state */ }; +struct acpi_processor_throttling_arg { + struct acpi_processor *pr; + int target_state; + bool force; +}; + #define THROTTLING_PRECHANGE (1) #define THROTTLING_POSTCHANGE (2) @@ -1062,16 +1068,24 @@ static int acpi_processor_set_throttling_ptc(struct acpi_processor *pr, return 0; } +static long acpi_processor_throttling_fn(void *data) +{ + struct acpi_processor_throttling_arg *arg = data; + struct acpi_processor *pr = arg->pr; + + return pr->throttling.acpi_processor_set_throttling(pr, + arg->target_state, arg->force); +} + int acpi_processor_set_throttling(struct acpi_processor *pr, int state, bool force) { - cpumask_var_t saved_mask; int ret = 0; unsigned int i; struct acpi_processor *match_pr; struct acpi_processor_throttling *p_throttling; + struct acpi_processor_throttling_arg arg; struct throttling_tstate t_state; - cpumask_var_t online_throttling_cpus; if (!pr) return -EINVAL; @@ -1082,14 +1096,6 @@ int acpi_processor_set_throttling(struct acpi_processor *pr, if ((state < 0) || (state > (pr->throttling.state_count - 1))) return -EINVAL; - if (!alloc_cpumask_var(&saved_mask, GFP_KERNEL)) - return -ENOMEM; - - if (!alloc_cpumask_var(&online_throttling_cpus, GFP_KERNEL)) { - free_cpumask_var(saved_mask); - return -ENOMEM; - } - if (cpu_is_offline(pr->id)) { /* * the cpu pointed by pr->id is offline. Unnecessary to change @@ -1098,17 +1104,15 @@ int acpi_processor_set_throttling(struct acpi_processor *pr, return -ENODEV; } - cpumask_copy(saved_mask, ¤t->cpus_allowed); t_state.target_state = state; p_throttling = &(pr->throttling); - cpumask_and(online_throttling_cpus, cpu_online_mask, - p_throttling->shared_cpu_map); + /* * The throttling notifier will be called for every * affected cpu in order to get one proper T-state. * The notifier event is THROTTLING_PRECHANGE. */ - for_each_cpu(i, online_throttling_cpus) { + for_each_cpu_and(i, cpu_online_mask, p_throttling->shared_cpu_map) { t_state.cpu = i; acpi_processor_throttling_notifier(THROTTLING_PRECHANGE, &t_state); @@ -1120,21 +1124,18 @@ int acpi_processor_set_throttling(struct acpi_processor *pr, * it can be called only for the cpu pointed by pr. */ if (p_throttling->shared_type == DOMAIN_COORD_TYPE_SW_ANY) { - /* FIXME: use work_on_cpu() */ - if (set_cpus_allowed_ptr(current, cpumask_of(pr->id))) { - /* Can't migrate to the pr->id CPU. Exit */ - ret = -ENODEV; - goto exit; - } - ret = p_throttling->acpi_processor_set_throttling(pr, - t_state.target_state, force); + arg.pr = pr; + arg.target_state = state; + arg.force = force; + ret = work_on_cpu(pr->id, acpi_processor_throttling_fn, &arg); } else { /* * When the T-state coordination is SW_ALL or HW_ALL, * it is necessary to set T-state for every affected * cpus. */ - for_each_cpu(i, online_throttling_cpus) { + for_each_cpu_and(i, cpu_online_mask, + p_throttling->shared_cpu_map) { match_pr = per_cpu(processors, i); /* * If the pointer is invalid, we will report the @@ -1155,13 +1156,12 @@ int acpi_processor_set_throttling(struct acpi_processor *pr, "on CPU %d\n", i)); continue; } - t_state.cpu = i; - /* FIXME: use work_on_cpu() */ - if (set_cpus_allowed_ptr(current, cpumask_of(i))) - continue; - ret = match_pr->throttling. - acpi_processor_set_throttling( - match_pr, t_state.target_state, force); + + arg.pr = match_pr; + arg.target_state = state; + arg.force = force; + ret = work_on_cpu(pr->id, acpi_processor_throttling_fn, + &arg); } } /* @@ -1170,17 +1170,12 @@ int acpi_processor_set_throttling(struct acpi_processor *pr, * affected cpu to update the T-states. * The notifier event is THROTTLING_POSTCHANGE */ - for_each_cpu(i, online_throttling_cpus) { + for_each_cpu_and(i, cpu_online_mask, p_throttling->shared_cpu_map) { t_state.cpu = i; acpi_processor_throttling_notifier(THROTTLING_POSTCHANGE, &t_state); } - /* restore the previous state */ - /* FIXME: use work_on_cpu() */ - set_cpus_allowed_ptr(current, saved_mask); -exit: - free_cpumask_var(online_throttling_cpus); - free_cpumask_var(saved_mask); + return ret; } -- 1.8.3.2