diff options
Diffstat (limited to 'mm/mempolicy.c')
| -rw-r--r-- | mm/mempolicy.c | 130 |
1 files changed, 72 insertions, 58 deletions
diff --git a/mm/mempolicy.c b/mm/mempolicy.c index d1b315e98627..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 @@ -2595,8 +2623,7 @@ void numa_default_policy(void) */ /* - * "local" is pseudo-policy: MPOL_PREFERRED with MPOL_F_LOCAL flag - * Used only for mpol_parse_str() and mpol_to_str() + * "local" is implemented internally by MPOL_PREFERRED with MPOL_F_LOCAL flag. */ static const char * const policy_modes[] = { @@ -2610,28 +2637,20 @@ static const char * const policy_modes[] = #ifdef CONFIG_TMPFS /** - * mpol_parse_str - parse string to mempolicy + * mpol_parse_str - parse string to mempolicy, for tmpfs mpol mount option. * @str: string containing mempolicy to parse * @mpol: pointer to struct mempolicy pointer, returned on success. - * @no_context: flag whether to "contextualize" the mempolicy * * Format of input: * <mode>[=<flags>][:<nodelist>] * - * if @no_context is true, save the input nodemask in w.user_nodemask in - * the returned mempolicy. This will be used to "clone" the mempolicy in - * a specific context [cpuset] at a later time. Used to parse tmpfs mpol - * mount option. Note that if 'static' or 'relative' mode flags were - * specified, the input nodemask will already have been saved. Saving - * it again is redundant, but safe. - * * On success, returns 0, else 1 */ -int mpol_parse_str(char *str, struct mempolicy **mpol, int no_context) +int mpol_parse_str(char *str, struct mempolicy **mpol) { struct mempolicy *new = NULL; unsigned short mode; - unsigned short uninitialized_var(mode_flags); + unsigned short mode_flags; nodemask_t nodes; char *nodelist = strchr(str, ':'); char *flags = strchr(str, '='); @@ -2719,24 +2738,23 @@ int mpol_parse_str(char *str, struct mempolicy **mpol, int no_context) if (IS_ERR(new)) goto out; - if (no_context) { - /* save for contextualization */ - new->w.user_nodemask = nodes; - } else { - int ret; - NODEMASK_SCRATCH(scratch); - if (scratch) { - task_lock(current); - ret = mpol_set_nodemask(new, &nodes, scratch); - task_unlock(current); - } else - ret = -ENOMEM; - NODEMASK_SCRATCH_FREE(scratch); - if (ret) { - mpol_put(new); - goto out; - } - } + /* + * Save nodes for mpol_to_str() to show the tmpfs mount options + * for /proc/mounts, /proc/pid/mounts and /proc/pid/mountinfo. + */ + if (mode != MPOL_PREFERRED) + new->v.nodes = nodes; + else if (nodelist) + new->v.preferred_node = first_node(nodes); + else + new->flags |= MPOL_F_LOCAL; + + /* + * Save nodes for contextualization: this will be used to "clone" + * the mempolicy in a specific context [cpuset] at a later time. + */ + new->w.user_nodemask = nodes; + err = 0; out: @@ -2756,13 +2774,12 @@ out: * @buffer: to contain formatted mempolicy string * @maxlen: length of @buffer * @pol: pointer to mempolicy to be formatted - * @no_context: "context free" mempolicy - use nodemask in w.user_nodemask * * Convert a mempolicy into a string. * Returns the number of characters in buffer (if positive) * or an error (negative) */ -int mpol_to_str(char *buffer, int maxlen, struct mempolicy *pol, int no_context) +int mpol_to_str(char *buffer, int maxlen, struct mempolicy *pol) { char *p = buffer; int l; @@ -2788,7 +2805,7 @@ int mpol_to_str(char *buffer, int maxlen, struct mempolicy *pol, int no_context) case MPOL_PREFERRED: nodes_clear(nodes); if (flags & MPOL_F_LOCAL) - mode = MPOL_LOCAL; /* pseudo-policy */ + mode = MPOL_LOCAL; else node_set(pol->v.preferred_node, nodes); break; @@ -2796,10 +2813,7 @@ int mpol_to_str(char *buffer, int maxlen, struct mempolicy *pol, int no_context) case MPOL_BIND: /* Fall through */ case MPOL_INTERLEAVE: - if (no_context) - nodes = pol->w.user_nodemask; - else - nodes = pol->v.nodes; + nodes = pol->v.nodes; break; default: |