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authorFrederic Weisbecker <frederic@kernel.org>2017-10-27 05:42:35 +0300
committerIngo Molnar <mingo@kernel.org>2017-10-27 10:55:29 +0300
commitde201559df872f83d0c08fb4effe3efd28e6cbc8 (patch)
tree6d23d89a604b67b2cb1d216515f4ce4ab3cd9f41 /kernel
parent5c4991e24c69737bd41fc2737b1e3980abbf73f9 (diff)
downloadlinux-de201559df872f83d0c08fb4effe3efd28e6cbc8.tar.xz
sched/isolation: Introduce housekeeping flags
Before we implement isolcpus under housekeeping, we need the isolation features to be more finegrained. For example some people want NOHZ_FULL without the full scheduler isolation, others want full scheduler isolation without NOHZ_FULL. So let's cut all these isolation features piecewise, at the risk of overcutting it right now. We can still merge some flags later if they always make sense together. Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Acked-by: Thomas Gleixner <tglx@linutronix.de> Cc: Chris Metcalf <cmetcalf@mellanox.com> Cc: Christoph Lameter <cl@linux.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Luiz Capitulino <lcapitulino@redhat.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Wanpeng Li <kernellwp@gmail.com> Link: http://lkml.kernel.org/r/1509072159-31808-9-git-send-email-frederic@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/rcu/tree_plugin.h2
-rw-r--r--kernel/rcu/update.c2
-rw-r--r--kernel/sched/core.c8
-rw-r--r--kernel/sched/fair.c2
-rw-r--r--kernel/sched/isolation.c26
-rw-r--r--kernel/watchdog.c3
6 files changed, 24 insertions, 19 deletions
diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h
index c7632f51c5a0..34125d23e58a 100644
--- a/kernel/rcu/tree_plugin.h
+++ b/kernel/rcu/tree_plugin.h
@@ -2584,7 +2584,7 @@ static void rcu_bind_gp_kthread(void)
if (!tick_nohz_full_enabled())
return;
- housekeeping_affine(current);
+ housekeeping_affine(current, HK_FLAG_RCU);
}
/* Record the current task on dyntick-idle entry. */
diff --git a/kernel/rcu/update.c b/kernel/rcu/update.c
index 79abeb0ca329..e3e60efaafee 100644
--- a/kernel/rcu/update.c
+++ b/kernel/rcu/update.c
@@ -719,7 +719,7 @@ static int __noreturn rcu_tasks_kthread(void *arg)
LIST_HEAD(rcu_tasks_holdouts);
/* Run on housekeeping CPUs by default. Sysadm can move if desired. */
- housekeeping_affine(current);
+ housekeeping_affine(current, HK_FLAG_RCU);
/*
* Each pass through the following loop makes one check for
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index d0fb448dd43a..2210c0203e51 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -527,7 +527,7 @@ int get_nohz_timer_target(void)
int i, cpu = smp_processor_id();
struct sched_domain *sd;
- if (!idle_cpu(cpu) && housekeeping_cpu(cpu))
+ if (!idle_cpu(cpu) && housekeeping_cpu(cpu, HK_FLAG_TIMER))
return cpu;
rcu_read_lock();
@@ -536,15 +536,15 @@ int get_nohz_timer_target(void)
if (cpu == i)
continue;
- if (!idle_cpu(i) && housekeeping_cpu(i)) {
+ if (!idle_cpu(i) && housekeeping_cpu(i, HK_FLAG_TIMER)) {
cpu = i;
goto unlock;
}
}
}
- if (!housekeeping_cpu(cpu))
- cpu = housekeeping_any_cpu();
+ if (!housekeeping_cpu(cpu, HK_FLAG_TIMER))
+ cpu = housekeeping_any_cpu(HK_FLAG_TIMER);
unlock:
rcu_read_unlock();
return cpu;
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index cdece8f967f0..f755de86a813 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -9027,7 +9027,7 @@ void nohz_balance_enter_idle(int cpu)
return;
/* Spare idle load balancing on CPUs that don't want to be disturbed: */
- if (!housekeeping_cpu(cpu))
+ if (!housekeeping_cpu(cpu, HK_FLAG_SCHED))
return;
if (test_bit(NOHZ_TICK_STOPPED, nohz_flags(cpu)))
diff --git a/kernel/sched/isolation.c b/kernel/sched/isolation.c
index bb8ba19a0235..37a138a780ff 100644
--- a/kernel/sched/isolation.c
+++ b/kernel/sched/isolation.c
@@ -15,37 +15,39 @@
DEFINE_STATIC_KEY_FALSE(housekeeping_overriden);
EXPORT_SYMBOL_GPL(housekeeping_overriden);
static cpumask_var_t housekeeping_mask;
+static unsigned int housekeeping_flags;
-int housekeeping_any_cpu(void)
+int housekeeping_any_cpu(enum hk_flags flags)
{
if (static_branch_unlikely(&housekeeping_overriden))
- return cpumask_any_and(housekeeping_mask, cpu_online_mask);
-
+ if (housekeeping_flags & flags)
+ return cpumask_any_and(housekeeping_mask, cpu_online_mask);
return smp_processor_id();
}
EXPORT_SYMBOL_GPL(housekeeping_any_cpu);
-const struct cpumask *housekeeping_cpumask(void)
+const struct cpumask *housekeeping_cpumask(enum hk_flags flags)
{
if (static_branch_unlikely(&housekeeping_overriden))
- return housekeeping_mask;
-
+ if (housekeeping_flags & flags)
+ return housekeeping_mask;
return cpu_possible_mask;
}
EXPORT_SYMBOL_GPL(housekeeping_cpumask);
-void housekeeping_affine(struct task_struct *t)
+void housekeeping_affine(struct task_struct *t, enum hk_flags flags)
{
if (static_branch_unlikely(&housekeeping_overriden))
- set_cpus_allowed_ptr(t, housekeeping_mask);
+ if (housekeeping_flags & flags)
+ set_cpus_allowed_ptr(t, housekeeping_mask);
}
EXPORT_SYMBOL_GPL(housekeeping_affine);
-bool housekeeping_test_cpu(int cpu)
+bool housekeeping_test_cpu(int cpu, enum hk_flags flags)
{
if (static_branch_unlikely(&housekeeping_overriden))
- return cpumask_test_cpu(cpu, housekeeping_mask);
-
+ if (housekeeping_flags & flags)
+ return cpumask_test_cpu(cpu, housekeeping_mask);
return true;
}
EXPORT_SYMBOL_GPL(housekeeping_test_cpu);
@@ -65,6 +67,8 @@ void __init housekeeping_init(void)
cpumask_andnot(housekeeping_mask,
cpu_possible_mask, tick_nohz_full_mask);
+ housekeeping_flags = HK_FLAG_TIMER | HK_FLAG_RCU | HK_FLAG_MISC;
+
static_branch_enable(&housekeeping_overriden);
/* We need at least one CPU to handle housekeeping work */
diff --git a/kernel/watchdog.c b/kernel/watchdog.c
index 562652c9c815..e9e2ebb3db29 100644
--- a/kernel/watchdog.c
+++ b/kernel/watchdog.c
@@ -777,7 +777,8 @@ void __init lockup_detector_init(void)
if (tick_nohz_full_enabled())
pr_info("Disabling watchdog on nohz_full cores by default\n");
- cpumask_copy(&watchdog_cpumask, housekeeping_cpumask());
+ cpumask_copy(&watchdog_cpumask,
+ housekeeping_cpumask(HK_FLAG_TIMER));
if (!watchdog_nmi_probe())
nmi_watchdog_available = true;