mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-23 17:30:02 +00:00
![Tejun Heo](/assets/img/avatar_default.png)
Currently, when a cpu goes down, cpu_active is cleared before CPU_DOWN_PREPARE starts and cpuset configuration is updated from a default priority cpu notifier. When a cpu is coming up, it's set before CPU_ONLINE but cpuset configuration again is updated from the same cpu notifier. For cpu notifiers, this presents an inconsistent state. Threads which a CPU_DOWN_PREPARE notifier expects to be bound to the CPU can be migrated to other cpus because the cpu is no more inactive. Fix it by updating cpu_active in the highest priority cpu notifier and cpuset configuration in the second highest when a cpu is coming up. Down path is updated similarly. This guarantees that all other cpu notifiers see consistent cpu_active and cpuset configuration. cpuset_track_online_cpus() notifier is converted to cpuset_update_active_cpus() which just updates the configuration and now called from cpuset_cpu_[in]active() notifiers registered from sched_init_smp(). If cpuset is disabled, cpuset_update_active_cpus() degenerates into partition_sched_domains() making separate notifier for !CONFIG_CPUSETS unnecessary. This problem is triggered by cmwq. During CPU_DOWN_PREPARE, hotplug callback creates a kthread and kthread_bind()s it to the target cpu, and the thread is expected to run on that cpu. * Ingo's test discovered __cpuinit/exit markups were incorrect. Fixed. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Ingo Molnar <mingo@elte.hu> Cc: Paul Menage <menage@google.com>
247 lines
5.7 KiB
C
247 lines
5.7 KiB
C
#ifndef _LINUX_CPUSET_H
|
|
#define _LINUX_CPUSET_H
|
|
/*
|
|
* cpuset interface
|
|
*
|
|
* Copyright (C) 2003 BULL SA
|
|
* Copyright (C) 2004-2006 Silicon Graphics, Inc.
|
|
*
|
|
*/
|
|
|
|
#include <linux/sched.h>
|
|
#include <linux/cpumask.h>
|
|
#include <linux/nodemask.h>
|
|
#include <linux/cgroup.h>
|
|
#include <linux/mm.h>
|
|
|
|
#ifdef CONFIG_CPUSETS
|
|
|
|
extern int number_of_cpusets; /* How many cpusets are defined in system? */
|
|
|
|
extern int cpuset_init(void);
|
|
extern void cpuset_init_smp(void);
|
|
extern void cpuset_update_active_cpus(void);
|
|
extern void cpuset_cpus_allowed(struct task_struct *p, struct cpumask *mask);
|
|
extern int cpuset_cpus_allowed_fallback(struct task_struct *p);
|
|
extern nodemask_t cpuset_mems_allowed(struct task_struct *p);
|
|
#define cpuset_current_mems_allowed (current->mems_allowed)
|
|
void cpuset_init_current_mems_allowed(void);
|
|
int cpuset_nodemask_valid_mems_allowed(nodemask_t *nodemask);
|
|
|
|
extern int __cpuset_node_allowed_softwall(int node, gfp_t gfp_mask);
|
|
extern int __cpuset_node_allowed_hardwall(int node, gfp_t gfp_mask);
|
|
|
|
static inline int cpuset_node_allowed_softwall(int node, gfp_t gfp_mask)
|
|
{
|
|
return number_of_cpusets <= 1 ||
|
|
__cpuset_node_allowed_softwall(node, gfp_mask);
|
|
}
|
|
|
|
static inline int cpuset_node_allowed_hardwall(int node, gfp_t gfp_mask)
|
|
{
|
|
return number_of_cpusets <= 1 ||
|
|
__cpuset_node_allowed_hardwall(node, gfp_mask);
|
|
}
|
|
|
|
static inline int cpuset_zone_allowed_softwall(struct zone *z, gfp_t gfp_mask)
|
|
{
|
|
return cpuset_node_allowed_softwall(zone_to_nid(z), gfp_mask);
|
|
}
|
|
|
|
static inline int cpuset_zone_allowed_hardwall(struct zone *z, gfp_t gfp_mask)
|
|
{
|
|
return cpuset_node_allowed_hardwall(zone_to_nid(z), gfp_mask);
|
|
}
|
|
|
|
extern int cpuset_mems_allowed_intersects(const struct task_struct *tsk1,
|
|
const struct task_struct *tsk2);
|
|
|
|
#define cpuset_memory_pressure_bump() \
|
|
do { \
|
|
if (cpuset_memory_pressure_enabled) \
|
|
__cpuset_memory_pressure_bump(); \
|
|
} while (0)
|
|
extern int cpuset_memory_pressure_enabled;
|
|
extern void __cpuset_memory_pressure_bump(void);
|
|
|
|
extern const struct file_operations proc_cpuset_operations;
|
|
struct seq_file;
|
|
extern void cpuset_task_status_allowed(struct seq_file *m,
|
|
struct task_struct *task);
|
|
|
|
extern int cpuset_mem_spread_node(void);
|
|
extern int cpuset_slab_spread_node(void);
|
|
|
|
static inline int cpuset_do_page_mem_spread(void)
|
|
{
|
|
return current->flags & PF_SPREAD_PAGE;
|
|
}
|
|
|
|
static inline int cpuset_do_slab_mem_spread(void)
|
|
{
|
|
return current->flags & PF_SPREAD_SLAB;
|
|
}
|
|
|
|
extern int current_cpuset_is_being_rebound(void);
|
|
|
|
extern void rebuild_sched_domains(void);
|
|
|
|
extern void cpuset_print_task_mems_allowed(struct task_struct *p);
|
|
|
|
/*
|
|
* reading current mems_allowed and mempolicy in the fastpath must protected
|
|
* by get_mems_allowed()
|
|
*/
|
|
static inline void get_mems_allowed(void)
|
|
{
|
|
current->mems_allowed_change_disable++;
|
|
|
|
/*
|
|
* ensure that reading mems_allowed and mempolicy happens after the
|
|
* update of ->mems_allowed_change_disable.
|
|
*
|
|
* the write-side task finds ->mems_allowed_change_disable is not 0,
|
|
* and knows the read-side task is reading mems_allowed or mempolicy,
|
|
* so it will clear old bits lazily.
|
|
*/
|
|
smp_mb();
|
|
}
|
|
|
|
static inline void put_mems_allowed(void)
|
|
{
|
|
/*
|
|
* ensure that reading mems_allowed and mempolicy before reducing
|
|
* mems_allowed_change_disable.
|
|
*
|
|
* the write-side task will know that the read-side task is still
|
|
* reading mems_allowed or mempolicy, don't clears old bits in the
|
|
* nodemask.
|
|
*/
|
|
smp_mb();
|
|
--ACCESS_ONCE(current->mems_allowed_change_disable);
|
|
}
|
|
|
|
static inline void set_mems_allowed(nodemask_t nodemask)
|
|
{
|
|
task_lock(current);
|
|
current->mems_allowed = nodemask;
|
|
task_unlock(current);
|
|
}
|
|
|
|
#else /* !CONFIG_CPUSETS */
|
|
|
|
static inline int cpuset_init(void) { return 0; }
|
|
static inline void cpuset_init_smp(void) {}
|
|
|
|
static inline void cpuset_update_active_cpus(void)
|
|
{
|
|
partition_sched_domains(1, NULL, NULL);
|
|
}
|
|
|
|
static inline void cpuset_cpus_allowed(struct task_struct *p,
|
|
struct cpumask *mask)
|
|
{
|
|
cpumask_copy(mask, cpu_possible_mask);
|
|
}
|
|
|
|
static inline int cpuset_cpus_allowed_fallback(struct task_struct *p)
|
|
{
|
|
cpumask_copy(&p->cpus_allowed, cpu_possible_mask);
|
|
return cpumask_any(cpu_active_mask);
|
|
}
|
|
|
|
static inline nodemask_t cpuset_mems_allowed(struct task_struct *p)
|
|
{
|
|
return node_possible_map;
|
|
}
|
|
|
|
#define cpuset_current_mems_allowed (node_states[N_HIGH_MEMORY])
|
|
static inline void cpuset_init_current_mems_allowed(void) {}
|
|
|
|
static inline int cpuset_nodemask_valid_mems_allowed(nodemask_t *nodemask)
|
|
{
|
|
return 1;
|
|
}
|
|
|
|
static inline int cpuset_node_allowed_softwall(int node, gfp_t gfp_mask)
|
|
{
|
|
return 1;
|
|
}
|
|
|
|
static inline int cpuset_node_allowed_hardwall(int node, gfp_t gfp_mask)
|
|
{
|
|
return 1;
|
|
}
|
|
|
|
static inline int cpuset_zone_allowed_softwall(struct zone *z, gfp_t gfp_mask)
|
|
{
|
|
return 1;
|
|
}
|
|
|
|
static inline int cpuset_zone_allowed_hardwall(struct zone *z, gfp_t gfp_mask)
|
|
{
|
|
return 1;
|
|
}
|
|
|
|
static inline int cpuset_mems_allowed_intersects(const struct task_struct *tsk1,
|
|
const struct task_struct *tsk2)
|
|
{
|
|
return 1;
|
|
}
|
|
|
|
static inline void cpuset_memory_pressure_bump(void) {}
|
|
|
|
static inline void cpuset_task_status_allowed(struct seq_file *m,
|
|
struct task_struct *task)
|
|
{
|
|
}
|
|
|
|
static inline int cpuset_mem_spread_node(void)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static inline int cpuset_slab_spread_node(void)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static inline int cpuset_do_page_mem_spread(void)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static inline int cpuset_do_slab_mem_spread(void)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static inline int current_cpuset_is_being_rebound(void)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static inline void rebuild_sched_domains(void)
|
|
{
|
|
partition_sched_domains(1, NULL, NULL);
|
|
}
|
|
|
|
static inline void cpuset_print_task_mems_allowed(struct task_struct *p)
|
|
{
|
|
}
|
|
|
|
static inline void set_mems_allowed(nodemask_t nodemask)
|
|
{
|
|
}
|
|
|
|
static inline void get_mems_allowed(void)
|
|
{
|
|
}
|
|
|
|
static inline void put_mems_allowed(void)
|
|
{
|
|
}
|
|
|
|
#endif /* !CONFIG_CPUSETS */
|
|
|
|
#endif /* _LINUX_CPUSET_H */
|