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Message-Id: <20220207155910.527133-9-frederic@kernel.org>
Date: Mon, 7 Feb 2022 16:59:10 +0100
From: Frederic Weisbecker <frederic@...nel.org>
To: Peter Zijlstra <peterz@...radead.org>
Cc: LKML <linux-kernel@...r.kernel.org>,
Frederic Weisbecker <frederic@...nel.org>,
Tejun Heo <tj@...nel.org>, Christoph Lameter <cl@...two.de>,
Juri Lelli <juri.lelli@...hat.com>,
Alex Belits <abelits@...vell.com>,
Nitesh Lal <nilal@...hat.com>,
Thomas Gleixner <tglx@...utronix.de>,
Paul Gortmaker <paul.gortmaker@...driver.com>,
Nicolas Saenz <nsaenzju@...hat.com>,
"Paul E . McKenney" <paulmck@...nel.org>,
Phil Auld <pauld@...hat.com>,
Marcelo Tosatti <mtosatti@...hat.com>,
Zefan Li <lizefan.x@...edance.com>
Subject: [PATCH 8/8] sched/isolation: Split housekeeping cpumask per isolation features
To prepare for supporting each housekeeping feature toward cpuset, split
the global housekeeping cpumask per HK_TYPE_* entry.
This will later allow, for example, to runtime modify the cpulist passed
through "isolcpus=", "nohz_full=" and "rcu_nocbs=" kernel boot
parameters.
Reviewed-by: Juri Lelli <juri.lelli@...hat.com>
Reviewed-by: Phil Auld <pauld@...hat.com>
Signed-off-by: Frederic Weisbecker <frederic@...nel.org>
Cc: Thomas Gleixner <tglx@...utronix.de>
Cc: Juri Lelli <juri.lelli@...hat.com>
Cc: Marcelo Tosatti <mtosatti@...hat.com>
Cc: Nitesh Lal <nilal@...hat.com>
Cc: Nicolas Saenz <nsaenzju@...hat.com>
Cc: Peter Zijlstra <peterz@...radead.org>
Cc: Christoph Lameter <cl@...two.de>
Cc: Tejun Heo <tj@...nel.org>
Cc: Zefan Li <lizefan.x@...edance.com>
Cc: Alex Belits <abelits@...vell.com>
Cc: Paul Gortmaker <paul.gortmaker@...driver.com>
Cc: Paul E. McKenney <paulmck@...nel.org>
---
kernel/sched/isolation.c | 91 +++++++++++++++++++++++++++-------------
1 file changed, 62 insertions(+), 29 deletions(-)
diff --git a/kernel/sched/isolation.c b/kernel/sched/isolation.c
index 883eee9fae22..b4d10815c45a 100644
--- a/kernel/sched/isolation.c
+++ b/kernel/sched/isolation.c
@@ -23,12 +23,17 @@ enum hk_flags {
DEFINE_STATIC_KEY_FALSE(housekeeping_overridden);
EXPORT_SYMBOL_GPL(housekeeping_overridden);
-static cpumask_var_t housekeeping_mask;
-static unsigned int housekeeping_flags;
+
+struct housekeeping {
+ cpumask_var_t cpumasks[HK_TYPE_MAX];
+ unsigned long flags;
+};
+
+static struct housekeeping housekeeping;
bool housekeeping_enabled(enum hk_type type)
{
- return !!(housekeeping_flags & BIT(type));
+ return !!(housekeeping.flags & BIT(type));
}
EXPORT_SYMBOL_GPL(housekeeping_enabled);
@@ -37,12 +42,12 @@ int housekeeping_any_cpu(enum hk_type type)
int cpu;
if (static_branch_unlikely(&housekeeping_overridden)) {
- if (housekeeping_flags & BIT(type)) {
- cpu = sched_numa_find_closest(housekeeping_mask, smp_processor_id());
+ if (housekeeping.flags & BIT(type)) {
+ cpu = sched_numa_find_closest(housekeeping.cpumasks[type], smp_processor_id());
if (cpu < nr_cpu_ids)
return cpu;
- return cpumask_any_and(housekeeping_mask, cpu_online_mask);
+ return cpumask_any_and(housekeeping.cpumasks[type], cpu_online_mask);
}
}
return smp_processor_id();
@@ -52,8 +57,8 @@ EXPORT_SYMBOL_GPL(housekeeping_any_cpu);
const struct cpumask *housekeeping_cpumask(enum hk_type type)
{
if (static_branch_unlikely(&housekeeping_overridden))
- if (housekeeping_flags & BIT(type))
- return housekeeping_mask;
+ if (housekeeping.flags & BIT(type))
+ return housekeeping.cpumasks[type];
return cpu_possible_mask;
}
EXPORT_SYMBOL_GPL(housekeeping_cpumask);
@@ -61,40 +66,53 @@ EXPORT_SYMBOL_GPL(housekeeping_cpumask);
void housekeeping_affine(struct task_struct *t, enum hk_type type)
{
if (static_branch_unlikely(&housekeeping_overridden))
- if (housekeeping_flags & BIT(type))
- set_cpus_allowed_ptr(t, housekeeping_mask);
+ if (housekeeping.flags & BIT(type))
+ set_cpus_allowed_ptr(t, housekeeping.cpumasks[type]);
}
EXPORT_SYMBOL_GPL(housekeeping_affine);
bool housekeeping_test_cpu(int cpu, enum hk_type type)
{
if (static_branch_unlikely(&housekeeping_overridden))
- if (housekeeping_flags & BIT(type))
- return cpumask_test_cpu(cpu, housekeeping_mask);
+ if (housekeeping.flags & BIT(type))
+ return cpumask_test_cpu(cpu, housekeeping.cpumasks[type]);
return true;
}
EXPORT_SYMBOL_GPL(housekeeping_test_cpu);
void __init housekeeping_init(void)
{
- if (!housekeeping_flags)
+ enum hk_type type;
+
+ if (!housekeeping.flags)
return;
static_branch_enable(&housekeeping_overridden);
- if (housekeeping_flags & HK_FLAG_TICK)
+ if (housekeeping.flags & HK_FLAG_TICK)
sched_tick_offload_init();
- /* We need at least one CPU to handle housekeeping work */
- WARN_ON_ONCE(cpumask_empty(housekeeping_mask));
+ for_each_set_bit(type, &housekeeping.flags, HK_TYPE_MAX) {
+ /* We need at least one CPU to handle housekeeping work */
+ WARN_ON_ONCE(cpumask_empty(housekeeping.cpumasks[type]));
+ }
}
-static int __init housekeeping_setup(char *str, enum hk_flags flags)
+static void __init housekeeping_setup_type(enum hk_type type,
+ cpumask_var_t housekeeping_staging)
+{
+
+ alloc_bootmem_cpumask_var(&housekeeping.cpumasks[type]);
+ cpumask_copy(housekeeping.cpumasks[type],
+ housekeeping_staging);
+}
+
+static int __init housekeeping_setup(char *str, unsigned long flags)
{
cpumask_var_t non_housekeeping_mask, housekeeping_staging;
int err = 0;
- if ((flags & HK_FLAG_TICK) && !(housekeeping_flags & HK_FLAG_TICK)) {
+ if ((flags & HK_FLAG_TICK) && !(housekeeping.flags & HK_FLAG_TICK)) {
if (!IS_ENABLED(CONFIG_NO_HZ_FULL)) {
pr_warn("Housekeeping: nohz unsupported."
" Build with CONFIG_NO_HZ_FULL\n");
@@ -115,26 +133,41 @@ static int __init housekeeping_setup(char *str, enum hk_flags flags)
if (!cpumask_intersects(cpu_present_mask, housekeeping_staging)) {
__cpumask_set_cpu(smp_processor_id(), housekeeping_staging);
__cpumask_clear_cpu(smp_processor_id(), non_housekeeping_mask);
- if (!housekeeping_flags) {
+ if (!housekeeping.flags) {
pr_warn("Housekeeping: must include one present CPU, "
"using boot CPU:%d\n", smp_processor_id());
}
}
- if (!housekeeping_flags) {
- alloc_bootmem_cpumask_var(&housekeeping_mask);
- cpumask_copy(housekeeping_mask, housekeeping_staging);
+ if (!housekeeping.flags) {
+ /* First setup call ("nohz_full=" or "isolcpus=") */
+ enum hk_type type;
+
+ for_each_set_bit(type, &flags, HK_TYPE_MAX)
+ housekeeping_setup_type(type, housekeeping_staging);
} else {
- if (!cpumask_equal(housekeeping_staging, housekeeping_mask)) {
- pr_warn("Housekeeping: nohz_full= must match isolcpus=\n");
- goto free_housekeeping_staging;
+ /* Second setup call ("nohz_full=" after "isolcpus=" or the reverse) */
+ enum hk_type type;
+ unsigned long iter_flags = flags & housekeeping.flags;
+
+ for_each_set_bit(type, &iter_flags, HK_TYPE_MAX) {
+ if (!cpumask_equal(housekeeping_staging,
+ housekeeping.cpumasks[type])) {
+ pr_warn("Housekeeping: nohz_full= must match isolcpus=\n");
+ goto free_housekeeping_staging;
+ }
}
+
+ iter_flags = flags & ~housekeeping.flags;
+
+ for_each_set_bit(type, &iter_flags, HK_TYPE_MAX)
+ housekeeping_setup_type(type, housekeeping_staging);
}
- if ((flags & HK_FLAG_TICK) && !(housekeeping_flags & HK_FLAG_TICK))
+ if ((flags & HK_FLAG_TICK) && !(housekeeping.flags & HK_FLAG_TICK))
tick_nohz_full_setup(non_housekeeping_mask);
- housekeeping_flags |= flags;
+ housekeeping.flags |= flags;
err = 1;
free_housekeeping_staging:
@@ -147,7 +180,7 @@ static int __init housekeeping_setup(char *str, enum hk_flags flags)
static int __init housekeeping_nohz_full_setup(char *str)
{
- unsigned int flags;
+ unsigned long flags;
flags = HK_FLAG_TICK | HK_FLAG_WQ | HK_FLAG_TIMER | HK_FLAG_RCU |
HK_FLAG_MISC | HK_FLAG_KTHREAD;
@@ -158,7 +191,7 @@ __setup("nohz_full=", housekeeping_nohz_full_setup);
static int __init housekeeping_isolcpus_setup(char *str)
{
- unsigned int flags = 0;
+ unsigned long flags = 0;
bool illegal = false;
char *par;
int len;
--
2.25.1
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