diff options
| -rw-r--r-- | include/linux/mempolicy.h | 6 | ||||
| -rw-r--r-- | include/uapi/linux/mempolicy.h | 8 | ||||
| -rw-r--r-- | kernel/cgroup/cpuset.c | 4 | ||||
| -rw-r--r-- | mm/mempolicy.c | 102 |
4 files changed, 21 insertions, 99 deletions
diff --git a/include/linux/mempolicy.h b/include/linux/mempolicy.h index ecb6cbe..3a58b4b 100644 --- a/include/linux/mempolicy.h +++ b/include/linux/mempolicy.h @@ -142,8 +142,7 @@ bool vma_policy_mof(struct vm_area_struct *vma); extern void numa_default_policy(void); extern void numa_policy_init(void); -extern void mpol_rebind_task(struct task_struct *tsk, const nodemask_t *new, - enum mpol_rebind_step step); +extern void mpol_rebind_task(struct task_struct *tsk, const nodemask_t *new); extern void mpol_rebind_mm(struct mm_struct *mm, nodemask_t *new); extern int huge_node(struct vm_area_struct *vma, @@ -260,8 +259,7 @@ static inline void numa_default_policy(void) } static inline void mpol_rebind_task(struct task_struct *tsk, - const nodemask_t *new, - enum mpol_rebind_step step) + const nodemask_t *new) { } diff --git a/include/uapi/linux/mempolicy.h b/include/uapi/linux/mempolicy.h index 9cd8b21..2a4d895 100644 --- a/include/uapi/linux/mempolicy.h +++ b/include/uapi/linux/mempolicy.h @@ -24,13 +24,6 @@ enum { MPOL_MAX, /* always last member of enum */ }; -enum mpol_rebind_step { - MPOL_REBIND_ONCE, /* do rebind work at once(not by two step) */ - MPOL_REBIND_STEP1, /* first step(set all the newly nodes) */ - MPOL_REBIND_STEP2, /* second step(clean all the disallowed nodes)*/ - MPOL_REBIND_NSTEP, -}; - /* Flags for set_mempolicy */ #define MPOL_F_STATIC_NODES (1 << 15) #define MPOL_F_RELATIVE_NODES (1 << 14) @@ -65,7 +58,6 @@ enum mpol_rebind_step { */ #define MPOL_F_SHARED (1 << 0) /* identify shared policies */ #define MPOL_F_LOCAL (1 << 1) /* preferred local allocation */ -#define MPOL_F_REBINDING (1 << 2) /* identify policies in rebinding */ #define MPOL_F_MOF (1 << 3) /* this policy wants migrate on fault */ #define MPOL_F_MORON (1 << 4) /* Migrate On protnone Reference On Node */ diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c index ae64341..5fd1bdb 100644 --- a/kernel/cgroup/cpuset.c +++ b/kernel/cgroup/cpuset.c @@ -1063,9 +1063,7 @@ static void cpuset_change_task_nodemask(struct task_struct *tsk, } nodes_or(tsk->mems_allowed, tsk->mems_allowed, *newmems); - mpol_rebind_task(tsk, newmems, MPOL_REBIND_STEP1); - - mpol_rebind_task(tsk, newmems, MPOL_REBIND_STEP2); + mpol_rebind_task(tsk, newmems); tsk->mems_allowed = *newmems; if (need_loop) { diff --git a/mm/mempolicy.c b/mm/mempolicy.c index c608076..0471814 100644 --- a/mm/mempolicy.c +++ b/mm/mempolicy.c @@ -146,22 +146,7 @@ struct mempolicy *get_task_policy(struct task_struct *p) static const struct mempolicy_operations { int (*create)(struct mempolicy *pol, const nodemask_t *nodes); - /* - * If read-side task has no lock to protect task->mempolicy, write-side - * task will rebind the task->mempolicy by two step. The first step is - * setting all the newly nodes, and the second step is cleaning all the - * disallowed nodes. In this way, we can avoid finding no node to alloc - * page. - * If we have a lock to protect task->mempolicy in read-side, we do - * rebind directly. - * - * step: - * MPOL_REBIND_ONCE - do rebind work at once - * MPOL_REBIND_STEP1 - set all the newly nodes - * MPOL_REBIND_STEP2 - clean all the disallowed nodes - */ - void (*rebind)(struct mempolicy *pol, const nodemask_t *nodes, - enum mpol_rebind_step step); + void (*rebind)(struct mempolicy *pol, const nodemask_t *nodes); } mpol_ops[MPOL_MAX]; static inline int mpol_store_user_nodemask(const struct mempolicy *pol) @@ -304,19 +289,11 @@ void __mpol_put(struct mempolicy *p) kmem_cache_free(policy_cache, p); } -static void mpol_rebind_default(struct mempolicy *pol, const nodemask_t *nodes, - enum mpol_rebind_step step) +static void mpol_rebind_default(struct mempolicy *pol, const nodemask_t *nodes) { } -/* - * step: - * MPOL_REBIND_ONCE - do rebind work at once - * MPOL_REBIND_STEP1 - set all the newly nodes - * MPOL_REBIND_STEP2 - clean all the disallowed nodes - */ -static void mpol_rebind_nodemask(struct mempolicy *pol, const nodemask_t *nodes, - enum mpol_rebind_step step) +static void mpol_rebind_nodemask(struct mempolicy *pol, const nodemask_t *nodes) { nodemask_t tmp; @@ -325,35 +302,19 @@ static void mpol_rebind_nodemask(struct mempolicy *pol, const nodemask_t *nodes, else if (pol->flags & MPOL_F_RELATIVE_NODES) mpol_relative_nodemask(&tmp, &pol->w.user_nodemask, nodes); else { - /* - * if step == 1, we use ->w.cpuset_mems_allowed to cache the - * result - */ - if (step == MPOL_REBIND_ONCE || step == MPOL_REBIND_STEP1) { - nodes_remap(tmp, pol->v.nodes, - pol->w.cpuset_mems_allowed, *nodes); - pol->w.cpuset_mems_allowed = step ? tmp : *nodes; - } else if (step == MPOL_REBIND_STEP2) { - tmp = pol->w.cpuset_mems_allowed; - pol->w.cpuset_mems_allowed = *nodes; - } else - BUG(); + nodes_remap(tmp, pol->v.nodes,pol->w.cpuset_mems_allowed, + *nodes); + pol->w.cpuset_mems_allowed = tmp; } if (nodes_empty(tmp)) tmp = *nodes; - if (step == MPOL_REBIND_STEP1) - nodes_or(pol->v.nodes, pol->v.nodes, tmp); - else if (step == MPOL_REBIND_ONCE || step == MPOL_REBIND_STEP2) - pol->v.nodes = tmp; - else - BUG(); + pol->v.nodes = tmp; } static void mpol_rebind_preferred(struct mempolicy *pol, - const nodemask_t *nodes, - enum mpol_rebind_step step) + const nodemask_t *nodes) { nodemask_t tmp; @@ -379,42 +340,19 @@ static void mpol_rebind_preferred(struct mempolicy *pol, /* * mpol_rebind_policy - Migrate a policy to a different set of nodes * - * If read-side task has no lock to protect task->mempolicy, write-side - * task will rebind the task->mempolicy by two step. The first step is - * setting all the newly nodes, and the second step is cleaning all the - * disallowed nodes. In this way, we can avoid finding no node to alloc - * page. - * If we have a lock to protect task->mempolicy in read-side, we do - * rebind directly. - * - * step: - * MPOL_REBIND_ONCE - do rebind work at once - * MPOL_REBIND_STEP1 - set all the newly nodes - * MPOL_REBIND_STEP2 - clean all the disallowed nodes + * Per-vma policies are protected by mmap_sem. Allocations using per-task + * policies are protected by task->mems_allowed_seq to prevent a premature + * OOM/allocation failure due to parallel nodemask modification. */ -static void mpol_rebind_policy(struct mempolicy *pol, const nodemask_t *newmask, - enum mpol_rebind_step step) +static void mpol_rebind_policy(struct mempolicy *pol, const nodemask_t *newmask) { if (!pol) return; - if (!mpol_store_user_nodemask(pol) && step == MPOL_REBIND_ONCE && + if (!mpol_store_user_nodemask(pol) && nodes_equal(pol->w.cpuset_mems_allowed, *newmask)) return; - if (step == MPOL_REBIND_STEP1 && (pol->flags & MPOL_F_REBINDING)) - return; - - if (step == MPOL_REBIND_STEP2 && !(pol->flags & MPOL_F_REBINDING)) - BUG(); - - if (step == MPOL_REBIND_STEP1) - pol->flags |= MPOL_F_REBINDING; - else if (step == MPOL_REBIND_STEP2) - pol->flags &= ~MPOL_F_REBINDING; - else if (step >= MPOL_REBIND_NSTEP) - BUG(); - - mpol_ops[pol->mode].rebind(pol, newmask, step); + mpol_ops[pol->mode].rebind(pol, newmask); } /* @@ -424,10 +362,9 @@ static void mpol_rebind_policy(struct mempolicy *pol, const nodemask_t *newmask, * Called with task's alloc_lock held. */ -void mpol_rebind_task(struct task_struct *tsk, const nodemask_t *new, - enum mpol_rebind_step step) +void mpol_rebind_task(struct task_struct *tsk, const nodemask_t *new) { - mpol_rebind_policy(tsk->mempolicy, new, step); + mpol_rebind_policy(tsk->mempolicy, new); } /* @@ -442,7 +379,7 @@ void mpol_rebind_mm(struct mm_struct *mm, nodemask_t *new) down_write(&mm->mmap_sem); for (vma = mm->mmap; vma; vma = vma->vm_next) - mpol_rebind_policy(vma->vm_policy, new, MPOL_REBIND_ONCE); + mpol_rebind_policy(vma->vm_policy, new); up_write(&mm->mmap_sem); } @@ -2101,10 +2038,7 @@ struct mempolicy *__mpol_dup(struct mempolicy *old) if (current_cpuset_is_being_rebound()) { nodemask_t mems = cpuset_mems_allowed(current); - if (new->flags & MPOL_F_REBINDING) - mpol_rebind_policy(new, &mems, MPOL_REBIND_STEP2); - else - mpol_rebind_policy(new, &mems, MPOL_REBIND_ONCE); + mpol_rebind_policy(new, &mems); } atomic_set(&new->refcnt, 1); return new; |
