Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751484AbaBZBOx (ORCPT ); Tue, 25 Feb 2014 20:14:53 -0500 Received: from mga01.intel.com ([192.55.52.88]:15622 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750755AbaBZBOw (ORCPT ); Tue, 25 Feb 2014 20:14:52 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.97,543,1389772800"; d="scan'208";a="488112865" Message-ID: <530D3E9E.7010206@intel.com> Date: Wed, 26 Feb 2014 09:08:46 +0800 From: Lan Tianyu User-Agent: Mozilla/5.0 (X11; Linux i686; rv:14.0) Gecko/20120714 Thunderbird/14.0 MIME-Version: 1.0 To: "Rafael J. Wysocki" CC: tj@kernel.org, jolsa@redhat.com, oleg@redhat.com, lenb@kernel.org, linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] ACPI/Processor: Rework processor throttling with work_on_cpu() References: <20140220151721.GB32719@redhat.com> <1392960945-30741-1-git-send-email-tianyu.lan@intel.com> <3890679.FyyHKXfXOb@vostro.rjw.lan> In-Reply-To: <3890679.FyyHKXfXOb@vostro.rjw.lan> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2014年02月26日 09:23, Rafael J. Wysocki wrote: > On Friday, February 21, 2014 01:35:45 PM Lan Tianyu wrote: >> acpi_processor_set_throttling() uses set_cpus_allowed_ptr() to make >> sure struct acpi_processor->acpi_processor_set_throttling() callback >> run on associated cpu. But the function maybe called in a worker which >> has been bound to a cpu. The patch is to replace set_cpus_allowed_ptr() >> with work_on_cpu(). >> >> Signed-off-by: Lan Tianyu >> --- >> drivers/acpi/processor_throttling.c | 70 +++++++++++++++++-------------------- >> 1 file changed, 33 insertions(+), 37 deletions(-) >> >> diff --git a/drivers/acpi/processor_throttling.c b/drivers/acpi/processor_throttling.c >> index 28baa05..2db105a 100644 >> --- a/drivers/acpi/processor_throttling.c >> +++ b/drivers/acpi/processor_throttling.c >> @@ -56,6 +56,12 @@ 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) >> >> @@ -1060,16 +1066,25 @@ 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; >> + struct acpi_processor_throttling *p_throttling = &pr->throttling; >> + >> + return p_throttling->acpi_processor_set_throttling(pr, >> + arg->target_state, arg->force); > > What about doing > > return pr->throttling.acpi_processor_set_throttling(...); > > directly without using the extra p_throttling pointer? This is better. I will update soon. > >> +} >> + >> 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; >> @@ -1080,14 +1095,6 @@ 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 >> @@ -1096,17 +1103,15 @@ 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); >> @@ -1118,21 +1123,18 @@ 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 >> @@ -1153,13 +1155,12 @@ 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); >> } >> } >> /* >> @@ -1168,17 +1169,12 @@ 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; >> } >> >> > -- Best regards Tianyu Lan -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/