6f1982fedd
We want to centralize the isolation management, done by the housekeeping subsystem. Therefore we need to handle the nohz_full= parameter from there. Since nohz_full= so far has involved unbound timers, watchdog, RCU and tilegx NAPI isolation, we keep that default behaviour. nohz_full= will be deprecated in the future. We want to control the isolation features from the isolcpus= parameter. 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/1509072159-31808-10-git-send-email-frederic@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
95 lines
2.6 KiB
C
95 lines
2.6 KiB
C
/*
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* Housekeeping management. Manage the targets for routine code that can run on
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* any CPU: unbound workqueues, timers, kthreads and any offloadable work.
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*
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* Copyright (C) 2017 Red Hat, Inc., Frederic Weisbecker
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*
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*/
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#include <linux/sched/isolation.h>
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#include <linux/tick.h>
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#include <linux/init.h>
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#include <linux/kernel.h>
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#include <linux/static_key.h>
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DEFINE_STATIC_KEY_FALSE(housekeeping_overriden);
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EXPORT_SYMBOL_GPL(housekeeping_overriden);
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static cpumask_var_t housekeeping_mask;
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static unsigned int housekeeping_flags;
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int housekeeping_any_cpu(enum hk_flags flags)
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{
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if (static_branch_unlikely(&housekeeping_overriden))
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if (housekeeping_flags & flags)
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return cpumask_any_and(housekeeping_mask, cpu_online_mask);
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return smp_processor_id();
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}
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EXPORT_SYMBOL_GPL(housekeeping_any_cpu);
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const struct cpumask *housekeeping_cpumask(enum hk_flags flags)
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{
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if (static_branch_unlikely(&housekeeping_overriden))
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if (housekeeping_flags & flags)
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return housekeeping_mask;
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return cpu_possible_mask;
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}
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EXPORT_SYMBOL_GPL(housekeeping_cpumask);
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void housekeeping_affine(struct task_struct *t, enum hk_flags flags)
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{
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if (static_branch_unlikely(&housekeeping_overriden))
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if (housekeeping_flags & flags)
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set_cpus_allowed_ptr(t, housekeeping_mask);
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}
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EXPORT_SYMBOL_GPL(housekeeping_affine);
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bool housekeeping_test_cpu(int cpu, enum hk_flags flags)
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{
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if (static_branch_unlikely(&housekeeping_overriden))
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if (housekeeping_flags & flags)
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return cpumask_test_cpu(cpu, housekeeping_mask);
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return true;
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}
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EXPORT_SYMBOL_GPL(housekeeping_test_cpu);
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void __init housekeeping_init(void)
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{
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if (!housekeeping_flags)
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return;
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static_branch_enable(&housekeeping_overriden);
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/* We need at least one CPU to handle housekeeping work */
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WARN_ON_ONCE(cpumask_empty(housekeeping_mask));
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}
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#ifdef CONFIG_NO_HZ_FULL
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static int __init housekeeping_nohz_full_setup(char *str)
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{
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cpumask_var_t non_housekeeping_mask;
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alloc_bootmem_cpumask_var(&non_housekeeping_mask);
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if (cpulist_parse(str, non_housekeeping_mask) < 0) {
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pr_warn("Housekeeping: Incorrect nohz_full cpumask\n");
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free_bootmem_cpumask_var(non_housekeeping_mask);
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return 0;
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}
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alloc_bootmem_cpumask_var(&housekeeping_mask);
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cpumask_andnot(housekeeping_mask, cpu_possible_mask, non_housekeeping_mask);
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if (cpumask_empty(housekeeping_mask))
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cpumask_set_cpu(smp_processor_id(), housekeeping_mask);
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housekeeping_flags = HK_FLAG_TICK | HK_FLAG_TIMER |
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HK_FLAG_RCU | HK_FLAG_MISC;
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tick_nohz_full_setup(non_housekeeping_mask);
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free_bootmem_cpumask_var(non_housekeeping_mask);
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return 1;
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}
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__setup("nohz_full=", housekeeping_nohz_full_setup);
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#endif
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