diff options
Diffstat (limited to 'include/linux/cpuset.h')
| -rw-r--r-- | include/linux/cpuset.h | 49 |
1 files changed, 49 insertions, 0 deletions
diff --git a/include/linux/cpuset.h b/include/linux/cpuset.h index a73454aec333..457ed765a116 100644 --- a/include/linux/cpuset.h +++ b/include/linux/cpuset.h @@ -69,6 +69,7 @@ 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) { @@ -86,9 +87,44 @@ 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 */ @@ -159,6 +195,11 @@ 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; @@ -187,6 +228,14 @@ 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 */ |