diff options
| -rw-r--r-- | fs/exec.c | 1 | ||||
| -rw-r--r-- | include/linux/cgroup.h | 15 | ||||
| -rw-r--r-- | include/linux/memcontrol.h | 16 | ||||
| -rw-r--r-- | include/linux/mm_types.h | 5 | ||||
| -rw-r--r-- | include/linux/sched.h | 13 | ||||
| -rw-r--r-- | init/Kconfig | 7 | ||||
| -rw-r--r-- | init/main.c | 1 | ||||
| -rw-r--r-- | kernel/cgroup.c | 30 | ||||
| -rw-r--r-- | kernel/exit.c | 83 | ||||
| -rw-r--r-- | kernel/fork.c | 11 | ||||
| -rw-r--r-- | mm/memcontrol.c | 28 |
11 files changed, 169 insertions, 41 deletions
@@ -735,6 +735,7 @@ static int exec_mmap(struct mm_struct *mm) tsk->active_mm = mm; activate_mm(active_mm, mm); task_unlock(tsk); + mm_update_next_owner(mm); arch_pick_mmap_layout(mm); if (old_mm) { up_read(&old_mm->mmap_sem); diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h index 0952480..e155aa7 100644 --- a/include/linux/cgroup.h +++ b/include/linux/cgroup.h @@ -305,6 +305,12 @@ struct cgroup_subsys { struct cgroup *cgrp); void (*post_clone)(struct cgroup_subsys *ss, struct cgroup *cgrp); void (*bind)(struct cgroup_subsys *ss, struct cgroup *root); + /* + * This routine is called with the task_lock of mm->owner held + */ + void (*mm_owner_changed)(struct cgroup_subsys *ss, + struct cgroup *old, + struct cgroup *new); int subsys_id; int active; int disabled; @@ -390,4 +396,13 @@ static inline int cgroupstats_build(struct cgroupstats *stats, #endif /* !CONFIG_CGROUPS */ +#ifdef CONFIG_MM_OWNER +extern void +cgroup_mm_owner_callbacks(struct task_struct *old, struct task_struct *new); +#else /* !CONFIG_MM_OWNER */ +static inline void +cgroup_mm_owner_callbacks(struct task_struct *old, struct task_struct *new) +{ +} +#endif /* CONFIG_MM_OWNER */ #endif /* _LINUX_CGROUP_H */ diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h index 8b1c429..e660877 100644 --- a/include/linux/memcontrol.h +++ b/include/linux/memcontrol.h @@ -27,9 +27,6 @@ struct mm_struct; #ifdef CONFIG_CGROUP_MEM_RES_CTLR -extern void mm_init_cgroup(struct mm_struct *mm, struct task_struct *p); -extern void mm_free_cgroup(struct mm_struct *mm); - #define page_reset_bad_cgroup(page) ((page)->page_cgroup = 0) extern struct page_cgroup *page_get_page_cgroup(struct page *page); @@ -48,8 +45,10 @@ extern unsigned long mem_cgroup_isolate_pages(unsigned long nr_to_scan, extern void mem_cgroup_out_of_memory(struct mem_cgroup *mem, gfp_t gfp_mask); int task_in_mem_cgroup(struct task_struct *task, const struct mem_cgroup *mem); +extern struct mem_cgroup *mem_cgroup_from_task(struct task_struct *p); + #define mm_match_cgroup(mm, cgroup) \ - ((cgroup) == rcu_dereference((mm)->mem_cgroup)) + ((cgroup) == mem_cgroup_from_task((mm)->owner)) extern int mem_cgroup_prepare_migration(struct page *page); extern void mem_cgroup_end_migration(struct page *page); @@ -73,15 +72,6 @@ extern long mem_cgroup_calc_reclaim_inactive(struct mem_cgroup *mem, struct zone *zone, int priority); #else /* CONFIG_CGROUP_MEM_RES_CTLR */ -static inline void mm_init_cgroup(struct mm_struct *mm, - struct task_struct *p) -{ -} - -static inline void mm_free_cgroup(struct mm_struct *mm) -{ -} - static inline void page_reset_bad_cgroup(struct page *page) { } diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h index e2bae8d..bc97bd5 100644 --- a/include/linux/mm_types.h +++ b/include/linux/mm_types.h @@ -225,8 +225,9 @@ struct mm_struct { /* aio bits */ rwlock_t ioctx_list_lock; /* aio lock */ struct kioctx *ioctx_list; -#ifdef CONFIG_CGROUP_MEM_RES_CTLR - struct mem_cgroup *mem_cgroup; +#ifdef CONFIG_MM_OWNER + struct task_struct *owner; /* The thread group leader that */ + /* owns the mm_struct. */ #endif }; diff --git a/include/linux/sched.h b/include/linux/sched.h index 024d72b..1d02bab 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -2148,6 +2148,19 @@ static inline void migration_init(void) #define TASK_SIZE_OF(tsk) TASK_SIZE #endif +#ifdef CONFIG_MM_OWNER +extern void mm_update_next_owner(struct mm_struct *mm); +extern void mm_init_owner(struct mm_struct *mm, struct task_struct *p); +#else +static inline void mm_update_next_owner(struct mm_struct *mm) +{ +} + +static inline void mm_init_owner(struct mm_struct *mm, struct task_struct *p) +{ +} +#endif /* CONFIG_MM_OWNER */ + #endif /* __KERNEL__ */ #endif diff --git a/init/Kconfig b/init/Kconfig index a345792..98fa96e 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -378,9 +378,13 @@ config RESOURCE_COUNTERS infrastructure that works with cgroups depends on CGROUPS +config MM_OWNER + bool + config CGROUP_MEM_RES_CTLR bool "Memory Resource Controller for Control Groups" depends on CGROUPS && RESOURCE_COUNTERS + select MM_OWNER help Provides a memory resource controller that manages both page cache and RSS memory. @@ -393,6 +397,9 @@ config CGROUP_MEM_RES_CTLR Only enable when you're ok with these trade offs and really sure you need the memory resource controller. + This config option also selects MM_OWNER config option, which + could in turn add some fork/exit overhead. + config SYSFS_DEPRECATED bool diff --git a/init/main.c b/init/main.c index 1116d2f..c62c98f 100644 --- a/init/main.c +++ b/init/main.c @@ -559,6 +559,7 @@ asmlinkage void __init start_kernel(void) printk(KERN_NOTICE); printk(linux_banner); setup_arch(&command_line); + mm_init_owner(&init_mm, &init_task); setup_command_line(command_line); unwind_setup(); setup_per_cpu_areas(); diff --git a/kernel/cgroup.c b/kernel/cgroup.c index abc4337..b9d467d 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -119,6 +119,7 @@ static int root_count; * be called. */ static int need_forkexit_callback; +static int need_mm_owner_callback __read_mostly; /* convenient tests for these bits */ inline int cgroup_is_removed(const struct cgroup *cgrp) @@ -2498,6 +2499,7 @@ static void __init cgroup_init_subsys(struct cgroup_subsys *ss) init_css_set.subsys[ss->subsys_id] = dummytop->subsys[ss->subsys_id]; need_forkexit_callback |= ss->fork || ss->exit; + need_mm_owner_callback |= !!ss->mm_owner_changed; /* At system boot, before all subsystems have been * registered, no tasks have been forked, so we don't @@ -2748,6 +2750,34 @@ void cgroup_fork_callbacks(struct task_struct *child) } } +#ifdef CONFIG_MM_OWNER +/** + * cgroup_mm_owner_callbacks - run callbacks when the mm->owner changes + * @p: the new owner + * + * Called on every change to mm->owner. mm_init_owner() does not + * invoke this routine, since it assigns the mm->owner the first time + * and does not change it. + */ +void cgroup_mm_owner_callbacks(struct task_struct *old, struct task_struct *new) +{ + struct cgroup *oldcgrp, *newcgrp; + + if (need_mm_owner_callback) { + int i; + for (i = 0; i < CGROUP_SUBSYS_COUNT; i++) { + struct cgroup_subsys *ss = subsys[i]; + oldcgrp = task_cgroup(old, ss->subsys_id); + newcgrp = task_cgroup(new, ss->subsys_id); + if (oldcgrp == newcgrp) + continue; + if (ss->mm_owner_changed) + ss->mm_owner_changed(ss, oldcgrp, newcgrp); + } + } +} +#endif /* CONFIG_MM_OWNER */ + /** * cgroup_post_fork - called on a new task after adding it to the task list * @child: the task in question diff --git a/kernel/exit.c b/kernel/exit.c index 2a9d98c..ae0f2c4 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -557,6 +557,88 @@ void exit_fs(struct task_struct *tsk) EXPORT_SYMBOL_GPL(exit_fs); +#ifdef CONFIG_MM_OWNER +/* + * Task p is exiting and it owned mm, lets find a new owner for it + */ +static inline int +mm_need_new_owner(struct mm_struct *mm, struct task_struct *p) +{ + /* + * If there are other users of the mm and the owner (us) is exiting + * we need to find a new owner to take on the responsibility. + */ + if (!mm) + return 0; + if (atomic_read(&mm->mm_users) <= 1) + return 0; + if (mm->owner != p) + return 0; + return 1; +} + +void mm_update_next_owner(struct mm_struct *mm) +{ + struct task_struct *c, *g, *p = current; + +retry: + if (!mm_need_new_owner(mm, p)) + return; + + read_lock(&tasklist_lock); + /* + * Search in the children + */ + list_for_each_entry(c, &p->children, sibling) { + if (c->mm == mm) + goto assign_new_owner; + } + + /* + * Search in the siblings + */ + list_for_each_entry(c, &p->parent->children, sibling) { + if (c->mm == mm) + goto assign_new_owner; + } + + /* + * Search through everything else. We should not get + * here often + */ + do_each_thread(g, c) { + if (c->mm == mm) + goto assign_new_owner; + } while_each_thread(g, c); + + read_unlock(&tasklist_lock); + return; + +assign_new_owner: + BUG_ON(c == p); + get_task_struct(c); + /* + * The task_lock protects c->mm from changing. + * We always want mm->owner->mm == mm + */ + task_lock(c); + /* + * Delay read_unlock() till we have the task_lock() + * to ensure that c does not slip away underneath us + */ + read_unlock(&tasklist_lock); + if (c->mm != mm) { + task_unlock(c); + put_task_struct(c); + goto retry; + } + cgroup_mm_owner_callbacks(mm->owner, c); + mm->owner = c; + task_unlock(c); + put_task_struct(c); +} +#endif /* CONFIG_MM_OWNER */ + /* * Turn us into a lazy TLB process if we * aren't already.. @@ -596,6 +678,7 @@ static void exit_mm(struct task_struct * tsk) /* We don't want this task to be frozen prematurely */ clear_freeze_flag(tsk); task_unlock(tsk); + mm_update_next_owner(mm); mmput(mm); } diff --git a/kernel/fork.c b/kernel/fork.c index 6067e42..156db96 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -381,14 +381,13 @@ static struct mm_struct * mm_init(struct mm_struct * mm, struct task_struct *p) mm->ioctx_list = NULL; mm->free_area_cache = TASK_UNMAPPED_BASE; mm->cached_hole_size = ~0UL; - mm_init_cgroup(mm, p); + mm_init_owner(mm, p); if (likely(!mm_alloc_pgd(mm))) { mm->def_flags = 0; return mm; } - mm_free_cgroup(mm); free_mm(mm); return NULL; } @@ -438,7 +437,6 @@ void mmput(struct mm_struct *mm) spin_unlock(&mmlist_lock); } put_swap_token(mm); - mm_free_cgroup(mm); mmdrop(mm); } } @@ -982,6 +980,13 @@ static void rt_mutex_init_task(struct task_struct *p) #endif } +#ifdef CONFIG_MM_OWNER +void mm_init_owner(struct mm_struct *mm, struct task_struct *p) +{ + mm->owner = p; +} +#endif /* CONFIG_MM_OWNER */ + /* * This creates a new process as a copy of the old one, * but does not actually start it yet. diff --git a/mm/memcontrol.c b/mm/memcontrol.c index d12795c..49d8081 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -236,26 +236,12 @@ static struct mem_cgroup *mem_cgroup_from_cont(struct cgroup *cont) css); } -static struct mem_cgroup *mem_cgroup_from_task(struct task_struct *p) +struct mem_cgroup *mem_cgroup_from_task(struct task_struct *p) { return container_of(task_subsys_state(p, mem_cgroup_subsys_id), struct mem_cgroup, css); } -void mm_init_cgroup(struct mm_struct *mm, struct task_struct *p) -{ - struct mem_cgroup *mem; - - mem = mem_cgroup_from_task(p); - css_get(&mem->css); - mm->mem_cgroup = mem; -} - -void mm_free_cgroup(struct mm_struct *mm) -{ - css_put(&mm->mem_cgroup->css); -} - static inline int page_cgroup_locked(struct page *page) { return bit_spin_is_locked(PAGE_CGROUP_LOCK_BIT, &page->page_cgroup); @@ -476,6 +462,7 @@ unsigned long mem_cgroup_isolate_pages(unsigned long nr_to_scan, int zid = zone_idx(z); struct mem_cgroup_per_zone *mz; + BUG_ON(!mem_cont); mz = mem_cgroup_zoneinfo(mem_cont, nid, zid); if (active) src = &mz->active_list; @@ -574,7 +561,7 @@ retry: mm = &init_mm; rcu_read_lock(); - mem = rcu_dereference(mm->mem_cgroup); + mem = mem_cgroup_from_task(rcu_dereference(mm->owner)); /* * For every charge from the cgroup, increment reference count */ @@ -985,10 +972,9 @@ mem_cgroup_create(struct cgroup_subsys *ss, struct cgroup *cont) struct mem_cgroup *mem; int node; - if (unlikely((cont->parent) == NULL)) { + if (unlikely((cont->parent) == NULL)) mem = &init_mem_cgroup; - init_mm.mem_cgroup = mem; - } else + else mem = kzalloc(sizeof(struct mem_cgroup), GFP_KERNEL); if (mem == NULL) @@ -1067,10 +1053,6 @@ static void mem_cgroup_move_task(struct cgroup_subsys *ss, if (!thread_group_leader(p)) goto out; - css_get(&mem->css); - rcu_assign_pointer(mm->mem_cgroup, mem); - css_put(&old_mem->css); - out: mmput(mm); } |
