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-rw-r--r--include/linux/mempolicy.h6
-rw-r--r--include/uapi/linux/mempolicy.h8
-rw-r--r--kernel/cgroup/cpuset.c4
-rw-r--r--mm/mempolicy.c102
4 files changed, 21 insertions, 99 deletions
diff --git a/include/linux/mempolicy.h b/include/linux/mempolicy.h
index ecb6cbeede5a..3a58b4be1b0c 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 9cd8b21dddbe..2a4d89508fec 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 ae643412948a..5fd1bdbaa381 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 c60807625fd5..047181452040 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;
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-07 03:37:24 +0000