diff options
author | Frederic Weisbecker <frederic@kernel.org> | 2017-10-27 04:42:35 +0200 |
---|---|---|
committer | Ingo Molnar <mingo@kernel.org> | 2017-10-27 09:55:29 +0200 |
commit | de201559df872f83d0c08fb4effe3efd28e6cbc8 (patch) | |
tree | 6d23d89a604b67b2cb1d216515f4ce4ab3cd9f41 /kernel | |
parent | 5c4991e24c69737bd41fc2737b1e3980abbf73f9 (diff) | |
download | linux-de201559df872f83d0c08fb4effe3efd28e6cbc8.tar.gz linux-de201559df872f83d0c08fb4effe3efd28e6cbc8.tar.bz2 linux-de201559df872f83d0c08fb4effe3efd28e6cbc8.zip |
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.h | 2 | ||||
-rw-r--r-- | kernel/rcu/update.c | 2 | ||||
-rw-r--r-- | kernel/sched/core.c | 8 | ||||
-rw-r--r-- | kernel/sched/fair.c | 2 | ||||
-rw-r--r-- | kernel/sched/isolation.c | 26 | ||||
-rw-r--r-- | kernel/watchdog.c | 3 |
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; |