diff options
| -rw-r--r-- | include/linux/mempolicy.h | 2 | ||||
| -rw-r--r-- | mm/mempolicy.c | 68 |
2 files changed, 49 insertions, 21 deletions
diff --git a/include/linux/mempolicy.h b/include/linux/mempolicy.h index 92bc9988a180..0d7df39a5885 100644 --- a/include/linux/mempolicy.h +++ b/include/linux/mempolicy.h @@ -123,7 +123,7 @@ struct sp_node { struct shared_policy { struct rb_root root; - struct mutex mutex; + spinlock_t lock; }; void mpol_shared_policy_init(struct shared_policy *sp, struct mempolicy *mpol); diff --git a/mm/mempolicy.c b/mm/mempolicy.c index 1cb200af3828..e2df1c1fb41f 100644 --- a/mm/mempolicy.c +++ b/mm/mempolicy.c @@ -2132,7 +2132,7 @@ bool __mpol_equal(struct mempolicy *a, struct mempolicy *b) */ /* lookup first element intersecting start-end */ -/* Caller holds sp->mutex */ +/* Caller holds sp->lock */ static struct sp_node * sp_lookup(struct shared_policy *sp, unsigned long start, unsigned long end) { @@ -2196,13 +2196,13 @@ mpol_shared_policy_lookup(struct shared_policy *sp, unsigned long idx) if (!sp->root.rb_node) return NULL; - mutex_lock(&sp->mutex); + spin_lock(&sp->lock); sn = sp_lookup(sp, idx, idx+1); if (sn) { mpol_get(sn->policy); pol = sn->policy; } - mutex_unlock(&sp->mutex); + spin_unlock(&sp->lock); return pol; } @@ -2328,6 +2328,14 @@ static void sp_delete(struct shared_policy *sp, struct sp_node *n) sp_free(n); } +static void sp_node_init(struct sp_node *node, unsigned long start, + unsigned long end, struct mempolicy *pol) +{ + node->start = start; + node->end = end; + node->policy = pol; +} + static struct sp_node *sp_alloc(unsigned long start, unsigned long end, struct mempolicy *pol) { @@ -2344,10 +2352,7 @@ static struct sp_node *sp_alloc(unsigned long start, unsigned long end, return NULL; } newpol->flags |= MPOL_F_SHARED; - - n->start = start; - n->end = end; - n->policy = newpol; + sp_node_init(n, start, end, newpol); return n; } @@ -2357,9 +2362,12 @@ static int shared_policy_replace(struct shared_policy *sp, unsigned long start, unsigned long end, struct sp_node *new) { struct sp_node *n; + struct sp_node *n_new = NULL; + struct mempolicy *mpol_new = NULL; int ret = 0; - mutex_lock(&sp->mutex); +restart: + spin_lock(&sp->lock); n = sp_lookup(sp, start, end); /* Take care of old policies in the same range. */ while (n && n->start < end) { @@ -2372,14 +2380,16 @@ static int shared_policy_replace(struct shared_policy *sp, unsigned long start, } else { /* Old policy spanning whole new range. */ if (n->end > end) { - struct sp_node *new2; - new2 = sp_alloc(end, n->end, n->policy); - if (!new2) { - ret = -ENOMEM; - goto out; - } + if (!n_new) + goto alloc_new; + + *mpol_new = *n->policy; + atomic_set(&mpol_new->refcnt, 1); + sp_node_init(n_new, n->end, end, mpol_new); + sp_insert(sp, n_new); n->end = start; - sp_insert(sp, new2); + n_new = NULL; + mpol_new = NULL; break; } else n->end = start; @@ -2390,9 +2400,27 @@ static int shared_policy_replace(struct shared_policy *sp, unsigned long start, } if (new) sp_insert(sp, new); -out: - mutex_unlock(&sp->mutex); + spin_unlock(&sp->lock); + ret = 0; + +err_out: + if (mpol_new) + mpol_put(mpol_new); + if (n_new) + kmem_cache_free(sn_cache, n_new); + return ret; + +alloc_new: + spin_unlock(&sp->lock); + ret = -ENOMEM; + n_new = kmem_cache_alloc(sn_cache, GFP_KERNEL); + if (!n_new) + goto err_out; + mpol_new = kmem_cache_alloc(policy_cache, GFP_KERNEL); + if (!mpol_new) + goto err_out; + goto restart; } /** @@ -2410,7 +2438,7 @@ void mpol_shared_policy_init(struct shared_policy *sp, struct mempolicy *mpol) int ret; sp->root = RB_ROOT; /* empty tree == default mempolicy */ - mutex_init(&sp->mutex); + spin_lock_init(&sp->lock); if (mpol) { struct vm_area_struct pvma; @@ -2476,14 +2504,14 @@ void mpol_free_shared_policy(struct shared_policy *p) if (!p->root.rb_node) return; - mutex_lock(&p->mutex); + spin_lock(&p->lock); next = rb_first(&p->root); while (next) { n = rb_entry(next, struct sp_node, nd); next = rb_next(&n->nd); sp_delete(p, n); } - mutex_unlock(&p->mutex); + spin_unlock(&p->lock); } #ifdef CONFIG_NUMA_BALANCING |