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Message-Id: <20221128132100.30253-3-ricardo.neri-calderon@linux.intel.com>
Date: Mon, 28 Nov 2022 05:20:40 -0800
From: Ricardo Neri <ricardo.neri-calderon@...ux.intel.com>
To: "Peter Zijlstra (Intel)" <peterz@...radead.org>,
Juri Lelli <juri.lelli@...hat.com>,
Vincent Guittot <vincent.guittot@...aro.org>
Cc: Ricardo Neri <ricardo.neri@...el.com>,
"Ravi V. Shankar" <ravi.v.shankar@...el.com>,
Ben Segall <bsegall@...gle.com>,
Daniel Bristot de Oliveira <bristot@...hat.com>,
Dietmar Eggemann <dietmar.eggemann@....com>,
Len Brown <len.brown@...el.com>, Mel Gorman <mgorman@...e.de>,
"Rafael J. Wysocki" <rafael.j.wysocki@...el.com>,
Srinivas Pandruvada <srinivas.pandruvada@...ux.intel.com>,
Steven Rostedt <rostedt@...dmis.org>,
Tim Chen <tim.c.chen@...ux.intel.com>,
Valentin Schneider <vschneid@...hat.com>, x86@...nel.org,
"Joel Fernandes (Google)" <joel@...lfernandes.org>,
linux-kernel@...r.kernel.org, linux-pm@...r.kernel.org,
Ricardo Neri <ricardo.neri-calderon@...ux.intel.com>,
"Tim C . Chen" <tim.c.chen@...el.com>
Subject: [PATCH v2 02/22] sched: Add interfaces for IPC classes
Add the interfaces that architectures shall implement to convey the data
to support IPC classes.
arch_update_ipcc() updates the IPC classification of the current task as
given by hardware.
arch_get_ipcc_score() provides a performance score for a given IPC class
when placed on a specific CPU. Higher scores indicate higher performance.
The number of classes and the score of each class of task are determined
by hardware.
Cc: Ben Segall <bsegall@...gle.com>
Cc: Daniel Bristot de Oliveira <bristot@...hat.com>
Cc: Dietmar Eggemann <dietmar.eggemann@....com>
Cc: Joel Fernandes (Google) <joel@...lfernandes.org>
Cc: Len Brown <len.brown@...el.com>
Cc: Mel Gorman <mgorman@...e.de>
Cc: Rafael J. Wysocki <rafael.j.wysocki@...el.com>
Cc: Srinivas Pandruvada <srinivas.pandruvada@...ux.intel.com>
Cc: Steven Rostedt <rostedt@...dmis.org>
Cc: Tim C. Chen <tim.c.chen@...el.com>
Cc: Valentin Schneider <vschneid@...hat.com>
Cc: x86@...nel.org
Cc: linux-pm@...r.kernel.org
Cc: linux-kernel@...r.kernel.org
Signed-off-by: Ricardo Neri <ricardo.neri-calderon@...ux.intel.com>
---
Changes since v1:
* Shortened the names of the IPCC interfaces (PeterZ):
sched_task_classes_enabled >> sched_ipcc_enabled
arch_has_task_classes >> arch_has_ipc_classes
arch_update_task_class >> arch_update_ipcc
arch_get_task_class_score >> arch_get_ipcc_score
* Removed smt_siblings_idle argument from arch_update_ipcc(). (PeterZ)
---
kernel/sched/sched.h | 60 +++++++++++++++++++++++++++++++++++++++++
kernel/sched/topology.c | 8 ++++++
2 files changed, 68 insertions(+)
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index b1d338a740e5..75e22baa2622 100644
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -2531,6 +2531,66 @@ void arch_scale_freq_tick(void)
}
#endif
+#ifdef CONFIG_IPC_CLASSES
+DECLARE_STATIC_KEY_FALSE(sched_ipcc);
+
+static inline bool sched_ipcc_enabled(void)
+{
+ return static_branch_unlikely(&sched_ipcc);
+}
+
+#ifndef arch_has_ipc_classes
+/**
+ * arch_has_ipc_classes() - Check whether hardware supports IPC classes of tasks
+ *
+ * Returns: true of IPC classes of tasks are supported.
+ */
+static __always_inline
+bool arch_has_ipc_classes(void)
+{
+ return false;
+}
+#endif
+
+#ifndef arch_update_ipcc
+/**
+ * arch_update_ipcc() - Update the IPC class of the current task
+ * @curr: The current task
+ *
+ * Request that the IPC classification of @curr is updated.
+ *
+ * Returns: none
+ */
+static __always_inline
+void arch_update_ipcc(struct task_struct *curr)
+{
+}
+#endif
+
+#ifndef arch_get_ipcc_score
+/**
+ * arch_get_ipcc_score() - Get the IPC score of a class of task
+ * @ipcc: The IPC class
+ * @cpu: A CPU number
+ *
+ * Returns the performance score of an IPC class when running on @cpu.
+ * Error when either @class or @cpu are invalid.
+ */
+static __always_inline
+int arch_get_ipcc_score(unsigned short ipcc, int cpu)
+{
+ return 1;
+}
+#endif
+#else /* CONFIG_IPC_CLASSES */
+
+#define arch_get_ipcc_score(ipcc, cpu) (-EINVAL)
+#define arch_update_ipcc(curr)
+
+static inline bool sched_ipcc_enabled(void) { return false; }
+
+#endif /* CONFIG_IPC_CLASSES */
+
#ifndef arch_scale_freq_capacity
/**
* arch_scale_freq_capacity - get the frequency scale factor of a given CPU.
diff --git a/kernel/sched/topology.c b/kernel/sched/topology.c
index 8154ef590b9f..eb1654b64df7 100644
--- a/kernel/sched/topology.c
+++ b/kernel/sched/topology.c
@@ -669,6 +669,9 @@ DEFINE_PER_CPU(struct sched_domain __rcu *, sd_numa);
DEFINE_PER_CPU(struct sched_domain __rcu *, sd_asym_packing);
DEFINE_PER_CPU(struct sched_domain __rcu *, sd_asym_cpucapacity);
DEFINE_STATIC_KEY_FALSE(sched_asym_cpucapacity);
+#ifdef CONFIG_IPC_CLASSES
+DEFINE_STATIC_KEY_FALSE(sched_ipcc);
+#endif
static void update_top_cache_domain(int cpu)
{
@@ -2388,6 +2391,11 @@ build_sched_domains(const struct cpumask *cpu_map, struct sched_domain_attr *att
if (has_asym)
static_branch_inc_cpuslocked(&sched_asym_cpucapacity);
+#ifdef CONFIG_IPC_CLASSES
+ if (arch_has_ipc_classes())
+ static_branch_enable_cpuslocked(&sched_ipcc);
+#endif
+
if (rq && sched_debug_verbose) {
pr_info("root domain span: %*pbl (max cpu_capacity = %lu)\n",
cpumask_pr_args(cpu_map), rq->rd->max_cpu_capacity);
--
2.25.1
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