X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=mm%2Fmempolicy.c;h=f11fdad06204c01f447d4bd7053ac930b7b636a4;hb=4f0ddfdffc8bef3a5eb9154734d68a6053194948;hp=c6c61ea6bb8ca827ea308dcf71ca51d398337a0f;hpb=f4e53d910b7dde2685b177f1e7c3e3e0b4a42f7b;p=safe%2Fjmp%2Flinux-2.6 diff --git a/mm/mempolicy.c b/mm/mempolicy.c index c6c61ea..f11fdad 100644 --- a/mm/mempolicy.c +++ b/mm/mempolicy.c @@ -88,10 +88,14 @@ #include #include #include +#include +#include #include #include +#include "internal.h" + /* Internal flags */ #define MPOL_MF_DISCONTIG_OK (MPOL_MF_INTERNAL << 0) /* Skip checks for continuous vmas */ #define MPOL_MF_INVERT (MPOL_MF_INTERNAL << 1) /* Invert check for nodemask */ @@ -104,9 +108,13 @@ static struct kmem_cache *sn_cache; policied. */ enum zone_type policy_zone = 0; +/* + * run-time system-wide default policy => local allocation + */ struct mempolicy default_policy = { .refcnt = ATOMIC_INIT(1), /* never free it */ - .policy = MPOL_DEFAULT, + .mode = MPOL_PREFERRED, + .flags = MPOL_F_LOCAL, }; static const struct mempolicy_operations { @@ -159,7 +167,7 @@ static int mpol_new_interleave(struct mempolicy *pol, const nodemask_t *nodes) static int mpol_new_preferred(struct mempolicy *pol, const nodemask_t *nodes) { if (!nodes) - pol->v.preferred_node = -1; /* local allocation */ + pol->flags |= MPOL_F_LOCAL; /* local allocation */ else if (nodes_empty(*nodes)) return -EINVAL; /* no allowed nodes */ else @@ -175,13 +183,58 @@ static int mpol_new_bind(struct mempolicy *pol, const nodemask_t *nodes) return 0; } -/* Create a new policy */ +/* + * mpol_set_nodemask is called after mpol_new() to set up the nodemask, if + * any, for the new policy. mpol_new() has already validated the nodes + * parameter with respect to the policy mode and flags. But, we need to + * handle an empty nodemask with MPOL_PREFERRED here. + * + * Must be called holding task's alloc_lock to protect task's mems_allowed + * and mempolicy. May also be called holding the mmap_semaphore for write. + */ +static int mpol_set_nodemask(struct mempolicy *pol, + const nodemask_t *nodes, struct nodemask_scratch *nsc) +{ + int ret; + + /* if mode is MPOL_DEFAULT, pol is NULL. This is right. */ + if (pol == NULL) + return 0; + /* Check N_HIGH_MEMORY */ + nodes_and(nsc->mask1, + cpuset_current_mems_allowed, node_states[N_HIGH_MEMORY]); + + VM_BUG_ON(!nodes); + if (pol->mode == MPOL_PREFERRED && nodes_empty(*nodes)) + nodes = NULL; /* explicit local allocation */ + else { + if (pol->flags & MPOL_F_RELATIVE_NODES) + mpol_relative_nodemask(&nsc->mask2, nodes,&nsc->mask1); + else + nodes_and(nsc->mask2, *nodes, nsc->mask1); + + if (mpol_store_user_nodemask(pol)) + pol->w.user_nodemask = *nodes; + else + pol->w.cpuset_mems_allowed = + cpuset_current_mems_allowed; + } + + if (nodes) + ret = mpol_ops[pol->mode].create(pol, &nsc->mask2); + else + ret = mpol_ops[pol->mode].create(pol, NULL); + return ret; +} + +/* + * This function just creates a new policy, does some check and simple + * initialization. You must invoke mpol_set_nodemask() to set nodes. + */ static struct mempolicy *mpol_new(unsigned short mode, unsigned short flags, nodemask_t *nodes) { struct mempolicy *policy; - nodemask_t cpuset_context_nmask; - int ret; pr_debug("setting mode %d flags %d nodes[0] %lx\n", mode, flags, nodes ? nodes_addr(*nodes)[0] : -1); @@ -189,7 +242,7 @@ static struct mempolicy *mpol_new(unsigned short mode, unsigned short flags, if (mode == MPOL_DEFAULT) { if (nodes && !nodes_empty(*nodes)) return ERR_PTR(-EINVAL); - return NULL; + return NULL; /* simply delete any existing policy */ } VM_BUG_ON(!nodes); @@ -203,7 +256,6 @@ static struct mempolicy *mpol_new(unsigned short mode, unsigned short flags, if (((flags & MPOL_F_STATIC_NODES) || (flags & MPOL_F_RELATIVE_NODES))) return ERR_PTR(-EINVAL); - nodes = NULL; /* flag local alloc */ } } else if (nodes_empty(*nodes)) return ERR_PTR(-EINVAL); @@ -211,36 +263,20 @@ static struct mempolicy *mpol_new(unsigned short mode, unsigned short flags, if (!policy) return ERR_PTR(-ENOMEM); atomic_set(&policy->refcnt, 1); - policy->policy = mode; + policy->mode = mode; policy->flags = flags; - if (nodes) { - /* - * cpuset related setup doesn't apply to local allocation - */ - cpuset_update_task_memory_state(); - if (flags & MPOL_F_RELATIVE_NODES) - mpol_relative_nodemask(&cpuset_context_nmask, nodes, - &cpuset_current_mems_allowed); - else - nodes_and(cpuset_context_nmask, *nodes, - cpuset_current_mems_allowed); - if (mpol_store_user_nodemask(policy)) - policy->w.user_nodemask = *nodes; - else - policy->w.cpuset_mems_allowed = - cpuset_mems_allowed(current); - } - - ret = mpol_ops[mode].create(policy, - nodes ? &cpuset_context_nmask : NULL); - if (ret < 0) { - kmem_cache_free(policy_cache, policy); - return ERR_PTR(ret); - } return policy; } +/* Slow path of a mpol destructor. */ +void __mpol_put(struct mempolicy *p) +{ + if (!atomic_dec_and_test(&p->refcnt)) + return; + kmem_cache_free(policy_cache, p); +} + static void mpol_rebind_default(struct mempolicy *pol, const nodemask_t *nodes) { } @@ -278,14 +314,15 @@ static void mpol_rebind_preferred(struct mempolicy *pol, if (pol->flags & MPOL_F_STATIC_NODES) { int node = first_node(pol->w.user_nodemask); - if (node_isset(node, *nodes)) + if (node_isset(node, *nodes)) { pol->v.preferred_node = node; - else - pol->v.preferred_node = -1; + pol->flags &= ~MPOL_F_LOCAL; + } else + pol->flags |= MPOL_F_LOCAL; } else if (pol->flags & MPOL_F_RELATIVE_NODES) { mpol_relative_nodemask(&tmp, &pol->w.user_nodemask, nodes); pol->v.preferred_node = first_node(tmp); - } else if (pol->v.preferred_node != -1) { + } else if (!(pol->flags & MPOL_F_LOCAL)) { pol->v.preferred_node = node_remap(pol->v.preferred_node, pol->w.cpuset_mems_allowed, *nodes); @@ -302,12 +339,14 @@ static void mpol_rebind_policy(struct mempolicy *pol, if (!mpol_store_user_nodemask(pol) && nodes_equal(pol->w.cpuset_mems_allowed, *newmask)) return; - mpol_ops[pol->policy].rebind(pol, newmask); + mpol_ops[pol->mode].rebind(pol, newmask); } /* * Wrapper for mpol_rebind_policy() that just requires task * pointer, and updates task mempolicy. + * + * Called with task's alloc_lock held. */ void mpol_rebind_task(struct task_struct *tsk, const nodemask_t *new) @@ -473,12 +512,6 @@ check_range(struct mm_struct *mm, unsigned long start, unsigned long end, int err; struct vm_area_struct *first, *vma, *prev; - if (flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL)) { - - err = migrate_prep(); - if (err) - return ERR_PTR(err); - } first = find_vma(mm, start); if (!first) @@ -590,13 +623,19 @@ static void mpol_set_task_struct_flag(void) static long do_set_mempolicy(unsigned short mode, unsigned short flags, nodemask_t *nodes) { - struct mempolicy *new; + struct mempolicy *new, *old; struct mm_struct *mm = current->mm; + NODEMASK_SCRATCH(scratch); + int ret; - new = mpol_new(mode, flags, nodes); - if (IS_ERR(new)) - return PTR_ERR(new); + if (!scratch) + return -ENOMEM; + new = mpol_new(mode, flags, nodes); + if (IS_ERR(new)) { + ret = PTR_ERR(new); + goto out; + } /* * prevent changing our mempolicy while show_numa_maps() * is using it. @@ -605,36 +644,53 @@ static long do_set_mempolicy(unsigned short mode, unsigned short flags, */ if (mm) down_write(&mm->mmap_sem); - mpol_put(current->mempolicy); + task_lock(current); + ret = mpol_set_nodemask(new, nodes, scratch); + if (ret) { + task_unlock(current); + if (mm) + up_write(&mm->mmap_sem); + mpol_put(new); + goto out; + } + old = current->mempolicy; current->mempolicy = new; mpol_set_task_struct_flag(); - if (new && new->policy == MPOL_INTERLEAVE && + if (new && new->mode == MPOL_INTERLEAVE && nodes_weight(new->v.nodes)) current->il_next = first_node(new->v.nodes); + task_unlock(current); if (mm) up_write(&mm->mmap_sem); - return 0; + mpol_put(old); + ret = 0; +out: + NODEMASK_SCRATCH_FREE(scratch); + return ret; } -/* Fill a zone bitmap for a policy */ -static void get_zonemask(struct mempolicy *p, nodemask_t *nodes) +/* + * Return nodemask for policy for get_mempolicy() query + * + * Called with task's alloc_lock held + */ +static void get_policy_nodemask(struct mempolicy *p, nodemask_t *nodes) { nodes_clear(*nodes); - switch (p->policy) { - case MPOL_DEFAULT: - break; + if (p == &default_policy) + return; + + switch (p->mode) { case MPOL_BIND: /* Fall through */ case MPOL_INTERLEAVE: *nodes = p->v.nodes; break; case MPOL_PREFERRED: - /* or use current node instead of memory_map? */ - if (p->v.preferred_node < 0) - *nodes = node_states[N_HIGH_MEMORY]; - else + if (!(p->flags & MPOL_F_LOCAL)) node_set(p->v.preferred_node, *nodes); + /* else return empty node mask for local allocation */ break; default: BUG(); @@ -663,7 +719,6 @@ static long do_get_mempolicy(int *policy, nodemask_t *nmask, struct vm_area_struct *vma = NULL; struct mempolicy *pol = current->mempolicy; - cpuset_update_task_memory_state(); if (flags & ~(unsigned long)(MPOL_F_NODE|MPOL_F_ADDR|MPOL_F_MEMS_ALLOWED)) return -EINVAL; @@ -672,11 +727,18 @@ static long do_get_mempolicy(int *policy, nodemask_t *nmask, if (flags & (MPOL_F_NODE|MPOL_F_ADDR)) return -EINVAL; *policy = 0; /* just so it's initialized */ + task_lock(current); *nmask = cpuset_current_mems_allowed; + task_unlock(current); return 0; } if (flags & MPOL_F_ADDR) { + /* + * Do NOT fall back to task policy if the + * vma/shared policy at addr is NULL. We + * want to return MPOL_DEFAULT in this case. + */ down_read(&mm->mmap_sem); vma = find_vma_intersection(mm, addr, addr+1); if (!vma) { @@ -691,7 +753,7 @@ static long do_get_mempolicy(int *policy, nodemask_t *nmask, return -EINVAL; if (!pol) - pol = &default_policy; + pol = &default_policy; /* indicates default behavior */ if (flags & MPOL_F_NODE) { if (flags & MPOL_F_ADDR) { @@ -700,14 +762,21 @@ static long do_get_mempolicy(int *policy, nodemask_t *nmask, goto out; *policy = err; } else if (pol == current->mempolicy && - pol->policy == MPOL_INTERLEAVE) { + pol->mode == MPOL_INTERLEAVE) { *policy = current->il_next; } else { err = -EINVAL; goto out; } - } else - *policy = pol->policy | pol->flags; + } else { + *policy = pol == &default_policy ? MPOL_DEFAULT : + pol->mode; + /* + * Internal mempolicy flags must be masked off before exposing + * the policy to userspace. + */ + *policy |= (pol->flags & MPOL_MODE_FLAGS); + } if (vma) { up_read(¤t->mm->mmap_sem); @@ -715,10 +784,14 @@ static long do_get_mempolicy(int *policy, nodemask_t *nmask, } err = 0; - if (nmask) - get_zonemask(pol, nmask); + if (nmask) { + task_lock(current); + get_policy_nodemask(pol, nmask); + task_unlock(current); + } out: + mpol_cond_put(pol); if (vma) up_read(¤t->mm->mmap_sem); return err; @@ -734,13 +807,18 @@ static void migrate_page_add(struct page *page, struct list_head *pagelist, /* * Avoid migrating a page that is shared with others. */ - if ((flags & MPOL_MF_MOVE_ALL) || page_mapcount(page) == 1) - isolate_lru_page(page, pagelist); + if ((flags & MPOL_MF_MOVE_ALL) || page_mapcount(page) == 1) { + if (!isolate_lru_page(page)) { + list_add_tail(&page->lru, pagelist); + inc_zone_page_state(page, NR_ISOLATED_ANON + + page_is_file_cache(page)); + } + } } static struct page *new_node_page(struct page *page, unsigned long node, int **x) { - return alloc_pages_node(node, GFP_HIGHUSER_MOVABLE, 0); + return alloc_pages_exact_node(node, GFP_HIGHUSER_MOVABLE, 0); } /* @@ -775,12 +853,15 @@ static int migrate_to_node(struct mm_struct *mm, int source, int dest, int do_migrate_pages(struct mm_struct *mm, const nodemask_t *from_nodes, const nodemask_t *to_nodes, int flags) { - LIST_HEAD(pagelist); int busy = 0; - int err = 0; + int err; nodemask_t tmp; - down_read(&mm->mmap_sem); + err = migrate_prep(); + if (err) + return err; + + down_read(&mm->mmap_sem); err = migrate_vmas(mm, from_nodes, to_nodes, flags); if (err) @@ -942,7 +1023,28 @@ static long do_mbind(unsigned long start, unsigned long len, start, start + len, mode, mode_flags, nmask ? nodes_addr(*nmask)[0] : -1); - down_write(&mm->mmap_sem); + if (flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL)) { + + err = migrate_prep(); + if (err) + goto mpol_out; + } + { + NODEMASK_SCRATCH(scratch); + if (scratch) { + down_write(&mm->mmap_sem); + task_lock(current); + err = mpol_set_nodemask(new, nmask, scratch); + task_unlock(current); + if (err) + up_write(&mm->mmap_sem); + } else + err = -ENOMEM; + NODEMASK_SCRATCH_FREE(scratch); + } + if (err) + goto mpol_out; + vma = check_range(mm, start, end, nmask, flags | MPOL_MF_INVERT, &pagelist); @@ -958,9 +1060,11 @@ static long do_mbind(unsigned long start, unsigned long len, if (!err && nr_failed && (flags & MPOL_MF_STRICT)) err = -EIO; - } + } else + putback_lru_pages(&pagelist); up_write(&mm->mmap_sem); + mpol_out: mpol_put(new); return err; } @@ -1032,10 +1136,9 @@ static int copy_nodes_to_user(unsigned long __user *mask, unsigned long maxnode, return copy_to_user(mask, nodes_addr(*nodes), copy) ? -EFAULT : 0; } -asmlinkage long sys_mbind(unsigned long start, unsigned long len, - unsigned long mode, - unsigned long __user *nmask, unsigned long maxnode, - unsigned flags) +SYSCALL_DEFINE6(mbind, unsigned long, start, unsigned long, len, + unsigned long, mode, unsigned long __user *, nmask, + unsigned long, maxnode, unsigned, flags) { nodemask_t nodes; int err; @@ -1055,8 +1158,8 @@ asmlinkage long sys_mbind(unsigned long start, unsigned long len, } /* Set the process memory policy */ -asmlinkage long sys_set_mempolicy(int mode, unsigned long __user *nmask, - unsigned long maxnode) +SYSCALL_DEFINE3(set_mempolicy, int, mode, unsigned long __user *, nmask, + unsigned long, maxnode) { int err; nodemask_t nodes; @@ -1074,10 +1177,11 @@ asmlinkage long sys_set_mempolicy(int mode, unsigned long __user *nmask, return do_set_mempolicy(mode, flags, &nodes); } -asmlinkage long sys_migrate_pages(pid_t pid, unsigned long maxnode, - const unsigned long __user *old_nodes, - const unsigned long __user *new_nodes) +SYSCALL_DEFINE4(migrate_pages, pid_t, pid, unsigned long, maxnode, + const unsigned long __user *, old_nodes, + const unsigned long __user *, new_nodes) { + const struct cred *cred = current_cred(), *tcred; struct mm_struct *mm; struct task_struct *task; nodemask_t old; @@ -1112,12 +1216,16 @@ asmlinkage long sys_migrate_pages(pid_t pid, unsigned long maxnode, * capabilities, superuser privileges or the same * userid as the target process. */ - if ((current->euid != task->suid) && (current->euid != task->uid) && - (current->uid != task->suid) && (current->uid != task->uid) && + rcu_read_lock(); + tcred = __task_cred(task); + if (cred->euid != tcred->suid && cred->euid != tcred->uid && + cred->uid != tcred->suid && cred->uid != tcred->uid && !capable(CAP_SYS_NICE)) { + rcu_read_unlock(); err = -EPERM; goto out; } + rcu_read_unlock(); task_nodes = cpuset_mems_allowed(task); /* Is the user allowed to access the target nodes? */ @@ -1144,10 +1252,9 @@ out: /* Retrieve NUMA policy */ -asmlinkage long sys_get_mempolicy(int __user *policy, - unsigned long __user *nmask, - unsigned long maxnode, - unsigned long addr, unsigned long flags) +SYSCALL_DEFINE5(get_mempolicy, int __user *, policy, + unsigned long __user *, nmask, unsigned long, maxnode, + unsigned long, addr, unsigned long, flags) { int err; int uninitialized_var(pval); @@ -1257,37 +1364,41 @@ asmlinkage long compat_sys_mbind(compat_ulong_t start, compat_ulong_t len, * * Returns effective policy for a VMA at specified address. * Falls back to @task or system default policy, as necessary. - * Returned policy has extra reference count if shared, vma, - * or some other task's policy [show_numa_maps() can pass - * @task != current]. It is the caller's responsibility to - * free the reference in these cases. + * Current or other task's task mempolicy and non-shared vma policies + * are protected by the task's mmap_sem, which must be held for read by + * the caller. + * Shared policies [those marked as MPOL_F_SHARED] require an extra reference + * count--added by the get_policy() vm_op, as appropriate--to protect against + * freeing by another task. It is the caller's responsibility to free the + * extra reference for shared policies. */ -static struct mempolicy * get_vma_policy(struct task_struct *task, +static struct mempolicy *get_vma_policy(struct task_struct *task, struct vm_area_struct *vma, unsigned long addr) { struct mempolicy *pol = task->mempolicy; - int shared_pol = 0; if (vma) { if (vma->vm_ops && vma->vm_ops->get_policy) { - pol = vma->vm_ops->get_policy(vma, addr); - shared_pol = 1; /* if pol non-NULL, add ref below */ - } else if (vma->vm_policy && - vma->vm_policy->policy != MPOL_DEFAULT) + struct mempolicy *vpol = vma->vm_ops->get_policy(vma, + addr); + if (vpol) + pol = vpol; + } else if (vma->vm_policy) pol = vma->vm_policy; } if (!pol) pol = &default_policy; - else if (!shared_pol && pol != current->mempolicy) - mpol_get(pol); /* vma or other task's policy */ return pol; } -/* Return a nodemask representing a mempolicy */ -static nodemask_t *nodemask_policy(gfp_t gfp, struct mempolicy *policy) +/* + * Return a nodemask representing a mempolicy for filtering nodes for + * page allocation + */ +static nodemask_t *policy_nodemask(gfp_t gfp, struct mempolicy *policy) { /* Lower zones don't get a nodemask applied for MPOL_BIND */ - if (unlikely(policy->policy == MPOL_BIND) && + if (unlikely(policy->mode == MPOL_BIND) && gfp_zone(gfp) >= policy_zone && cpuset_nodemask_valid_mems_allowed(&policy->v.nodes)) return &policy->v.nodes; @@ -1295,35 +1406,30 @@ static nodemask_t *nodemask_policy(gfp_t gfp, struct mempolicy *policy) return NULL; } -/* Return a zonelist representing a mempolicy */ -static struct zonelist *zonelist_policy(gfp_t gfp, struct mempolicy *policy) +/* Return a zonelist indicated by gfp for node representing a mempolicy */ +static struct zonelist *policy_zonelist(gfp_t gfp, struct mempolicy *policy) { - int nd; + int nd = numa_node_id(); - switch (policy->policy) { + switch (policy->mode) { case MPOL_PREFERRED: - nd = policy->v.preferred_node; - if (nd < 0) - nd = numa_node_id(); + if (!(policy->flags & MPOL_F_LOCAL)) + nd = policy->v.preferred_node; break; case MPOL_BIND: /* - * Normally, MPOL_BIND allocations node-local are node-local - * within the allowed nodemask. However, if __GFP_THISNODE is - * set and the current node is part of the mask, we use the - * the zonelist for the first node in the mask instead. + * Normally, MPOL_BIND allocations are node-local within the + * allowed nodemask. However, if __GFP_THISNODE is set and the + * current node is part of the mask, we use the zonelist for + * the first node in the mask instead. */ - nd = numa_node_id(); if (unlikely(gfp & __GFP_THISNODE) && unlikely(!node_isset(nd, policy->v.nodes))) nd = first_node(policy->v.nodes); break; case MPOL_INTERLEAVE: /* should not happen */ - case MPOL_DEFAULT: - nd = numa_node_id(); break; default: - nd = 0; BUG(); } return node_zonelist(nd, gfp); @@ -1347,12 +1453,23 @@ static unsigned interleave_nodes(struct mempolicy *policy) /* * Depending on the memory policy provide a node from which to allocate the * next slab entry. + * @policy must be protected by freeing by the caller. If @policy is + * the current task's mempolicy, this protection is implicit, as only the + * task can change it's policy. The system default policy requires no + * such protection. */ unsigned slab_node(struct mempolicy *policy) { - unsigned short pol = policy ? policy->policy : MPOL_DEFAULT; + if (!policy || policy->flags & MPOL_F_LOCAL) + return numa_node_id(); + + switch (policy->mode) { + case MPOL_PREFERRED: + /* + * handled MPOL_F_LOCAL above + */ + return policy->v.preferred_node; - switch (pol) { case MPOL_INTERLEAVE: return interleave_nodes(policy); @@ -1371,13 +1488,8 @@ unsigned slab_node(struct mempolicy *policy) return zone->node; } - case MPOL_PREFERRED: - if (policy->v.preferred_node >= 0) - return policy->v.preferred_node; - /* Fall through */ - default: - return numa_node_id(); + BUG(); } } @@ -1432,45 +1544,76 @@ static inline unsigned interleave_nid(struct mempolicy *pol, * @mpol = pointer to mempolicy pointer for reference counted mempolicy * @nodemask = pointer to nodemask pointer for MPOL_BIND nodemask * - * Returns a zonelist suitable for a huge page allocation. - * If the effective policy is 'BIND, returns pointer to local node's zonelist, - * and a pointer to the mempolicy's @nodemask for filtering the zonelist. - * If it is also a policy for which get_vma_policy() returns an extra - * reference, we must hold that reference until after the allocation. - * In that case, return policy via @mpol so hugetlb allocation can drop - * the reference. For non-'BIND referenced policies, we can/do drop the - * reference here, so the caller doesn't need to know about the special case - * for default and current task policy. + * Returns a zonelist suitable for a huge page allocation and a pointer + * to the struct mempolicy for conditional unref after allocation. + * If the effective policy is 'BIND, returns a pointer to the mempolicy's + * @nodemask for filtering the zonelist. */ struct zonelist *huge_zonelist(struct vm_area_struct *vma, unsigned long addr, gfp_t gfp_flags, struct mempolicy **mpol, nodemask_t **nodemask) { - struct mempolicy *pol = get_vma_policy(current, vma, addr); struct zonelist *zl; - *mpol = NULL; /* probably no unref needed */ + *mpol = get_vma_policy(current, vma, addr); *nodemask = NULL; /* assume !MPOL_BIND */ - if (pol->policy == MPOL_BIND) { - *nodemask = &pol->v.nodes; - } else if (pol->policy == MPOL_INTERLEAVE) { - unsigned nid; - nid = interleave_nid(pol, vma, addr, HPAGE_SHIFT); - if (unlikely(pol != &default_policy && - pol != current->mempolicy)) - __mpol_put(pol); /* finished with pol */ - return node_zonelist(nid, gfp_flags); + if (unlikely((*mpol)->mode == MPOL_INTERLEAVE)) { + zl = node_zonelist(interleave_nid(*mpol, vma, addr, + huge_page_shift(hstate_vma(vma))), gfp_flags); + } else { + zl = policy_zonelist(gfp_flags, *mpol); + if ((*mpol)->mode == MPOL_BIND) + *nodemask = &(*mpol)->v.nodes; } + return zl; +} - zl = zonelist_policy(GFP_HIGHUSER, pol); - if (unlikely(pol != &default_policy && pol != current->mempolicy)) { - if (pol->policy != MPOL_BIND) - __mpol_put(pol); /* finished with pol */ +/* + * init_nodemask_of_mempolicy + * + * If the current task's mempolicy is "default" [NULL], return 'false' + * to indicate default policy. Otherwise, extract the policy nodemask + * for 'bind' or 'interleave' policy into the argument nodemask, or + * initialize the argument nodemask to contain the single node for + * 'preferred' or 'local' policy and return 'true' to indicate presence + * of non-default mempolicy. + * + * We don't bother with reference counting the mempolicy [mpol_get/put] + * because the current task is examining it's own mempolicy and a task's + * mempolicy is only ever changed by the task itself. + * + * N.B., it is the caller's responsibility to free a returned nodemask. + */ +bool init_nodemask_of_mempolicy(nodemask_t *mask) +{ + struct mempolicy *mempolicy; + int nid; + + if (!(mask && current->mempolicy)) + return false; + + mempolicy = current->mempolicy; + switch (mempolicy->mode) { + case MPOL_PREFERRED: + if (mempolicy->flags & MPOL_F_LOCAL) + nid = numa_node_id(); else - *mpol = pol; /* unref needed after allocation */ + nid = mempolicy->v.preferred_node; + init_nodemask_of_node(mask, nid); + break; + + case MPOL_BIND: + /* Fall through */ + case MPOL_INTERLEAVE: + *mask = mempolicy->v.nodes; + break; + + default: + BUG(); } - return zl; + + return true; } #endif @@ -1517,31 +1660,27 @@ alloc_page_vma(gfp_t gfp, struct vm_area_struct *vma, unsigned long addr) struct mempolicy *pol = get_vma_policy(current, vma, addr); struct zonelist *zl; - cpuset_update_task_memory_state(); - - if (unlikely(pol->policy == MPOL_INTERLEAVE)) { + if (unlikely(pol->mode == MPOL_INTERLEAVE)) { unsigned nid; nid = interleave_nid(pol, vma, addr, PAGE_SHIFT); - if (unlikely(pol != &default_policy && - pol != current->mempolicy)) - __mpol_put(pol); /* finished with pol */ + mpol_cond_put(pol); return alloc_page_interleave(gfp, 0, nid); } - zl = zonelist_policy(gfp, pol); - if (pol != &default_policy && pol != current->mempolicy) { + zl = policy_zonelist(gfp, pol); + if (unlikely(mpol_needs_cond_ref(pol))) { /* - * slow path: ref counted policy -- shared or vma + * slow path: ref counted shared policy */ struct page *page = __alloc_pages_nodemask(gfp, 0, - zl, nodemask_policy(gfp, pol)); + zl, policy_nodemask(gfp, pol)); __mpol_put(pol); return page; } /* * fast path: default or task policy */ - return __alloc_pages_nodemask(gfp, 0, zl, nodemask_policy(gfp, pol)); + return __alloc_pages_nodemask(gfp, 0, zl, policy_nodemask(gfp, pol)); } /** @@ -1567,14 +1706,17 @@ struct page *alloc_pages_current(gfp_t gfp, unsigned order) { struct mempolicy *pol = current->mempolicy; - if ((gfp & __GFP_WAIT) && !in_interrupt()) - cpuset_update_task_memory_state(); if (!pol || in_interrupt() || (gfp & __GFP_THISNODE)) pol = &default_policy; - if (pol->policy == MPOL_INTERLEAVE) + + /* + * No reference counting needed for current->mempolicy + * nor system default_policy + */ + if (pol->mode == MPOL_INTERLEAVE) return alloc_page_interleave(gfp, order, interleave_nodes(pol)); return __alloc_pages_nodemask(gfp, order, - zonelist_policy(gfp, pol), nodemask_policy(gfp, pol)); + policy_zonelist(gfp, pol), policy_nodemask(gfp, pol)); } EXPORT_SYMBOL(alloc_pages_current); @@ -1602,6 +1744,28 @@ struct mempolicy *__mpol_dup(struct mempolicy *old) return new; } +/* + * If *frompol needs [has] an extra ref, copy *frompol to *tompol , + * eliminate the * MPOL_F_* flags that require conditional ref and + * [NOTE!!!] drop the extra ref. Not safe to reference *frompol directly + * after return. Use the returned value. + * + * Allows use of a mempolicy for, e.g., multiple allocations with a single + * policy lookup, even if the policy needs/has extra ref on lookup. + * shmem_readahead needs this. + */ +struct mempolicy *__mpol_cond_copy(struct mempolicy *tompol, + struct mempolicy *frompol) +{ + if (!mpol_needs_cond_ref(frompol)) + return frompol; + + *tompol = *frompol; + tompol->flags &= ~MPOL_F_SHARED; /* copy doesn't need unref */ + __mpol_put(frompol); + return tompol; +} + static int mpol_match_intent(const struct mempolicy *a, const struct mempolicy *b) { @@ -1617,34 +1781,24 @@ int __mpol_equal(struct mempolicy *a, struct mempolicy *b) { if (!a || !b) return 0; - if (a->policy != b->policy) + if (a->mode != b->mode) return 0; - if (a->policy != MPOL_DEFAULT && !mpol_match_intent(a, b)) + if (a->mode != MPOL_DEFAULT && !mpol_match_intent(a, b)) return 0; - switch (a->policy) { - case MPOL_DEFAULT: - return 1; + switch (a->mode) { case MPOL_BIND: /* Fall through */ case MPOL_INTERLEAVE: return nodes_equal(a->v.nodes, b->v.nodes); case MPOL_PREFERRED: - return a->v.preferred_node == b->v.preferred_node; + return a->v.preferred_node == b->v.preferred_node && + a->flags == b->flags; default: BUG(); return 0; } } -/* Slow path of a mpol destructor. */ -void __mpol_put(struct mempolicy *p) -{ - if (!atomic_dec_and_test(&p->refcnt)) - return; - p->policy = MPOL_DEFAULT; - kmem_cache_free(policy_cache, p); -} - /* * Shared memory backing store policy support. * @@ -1707,7 +1861,7 @@ static void sp_insert(struct shared_policy *sp, struct sp_node *new) rb_link_node(&new->nd, parent, p); rb_insert_color(&new->nd, &sp->root); pr_debug("inserting %lx-%lx: %d\n", new->start, new->end, - new->policy ? new->policy->policy : 0); + new->policy ? new->policy->mode : 0); } /* Find shared policy intersecting idx */ @@ -1747,6 +1901,7 @@ static struct sp_node *sp_alloc(unsigned long start, unsigned long end, n->start = start; n->end = end; mpol_get(pol); + pol->flags |= MPOL_F_SHARED; /* for unref */ n->policy = pol; return n; } @@ -1799,27 +1954,54 @@ restart: return 0; } -void mpol_shared_policy_init(struct shared_policy *info, unsigned short policy, - unsigned short flags, nodemask_t *policy_nodes) +/** + * mpol_shared_policy_init - initialize shared policy for inode + * @sp: pointer to inode shared policy + * @mpol: struct mempolicy to install + * + * Install non-NULL @mpol in inode's shared policy rb-tree. + * On entry, the current task has a reference on a non-NULL @mpol. + * This must be released on exit. + * This is called at get_inode() calls and we can use GFP_KERNEL. + */ +void mpol_shared_policy_init(struct shared_policy *sp, struct mempolicy *mpol) { - info->root = RB_ROOT; - spin_lock_init(&info->lock); - - if (policy != MPOL_DEFAULT) { - struct mempolicy *newpol; + int ret; - /* Falls back to MPOL_DEFAULT on any error */ - newpol = mpol_new(policy, flags, policy_nodes); - if (!IS_ERR(newpol)) { - /* Create pseudo-vma that contains just the policy */ - struct vm_area_struct pvma; + sp->root = RB_ROOT; /* empty tree == default mempolicy */ + spin_lock_init(&sp->lock); + + if (mpol) { + struct vm_area_struct pvma; + struct mempolicy *new; + NODEMASK_SCRATCH(scratch); + + if (!scratch) + return; + /* contextualize the tmpfs mount point mempolicy */ + new = mpol_new(mpol->mode, mpol->flags, &mpol->w.user_nodemask); + if (IS_ERR(new)) { + mpol_put(mpol); /* drop our ref on sb mpol */ + NODEMASK_SCRATCH_FREE(scratch); + return; /* no valid nodemask intersection */ + } - memset(&pvma, 0, sizeof(struct vm_area_struct)); - /* Policy covers entire file */ - pvma.vm_end = TASK_SIZE; - mpol_set_shared_policy(info, &pvma, newpol); - mpol_put(newpol); + task_lock(current); + ret = mpol_set_nodemask(new, &mpol->w.user_nodemask, scratch); + task_unlock(current); + mpol_put(mpol); /* drop our ref on sb mpol */ + if (ret) { + NODEMASK_SCRATCH_FREE(scratch); + mpol_put(new); + return; } + + /* Create pseudo-vma that contains just the policy */ + memset(&pvma, 0, sizeof(struct vm_area_struct)); + pvma.vm_end = TASK_SIZE; /* policy covers entire file */ + mpol_set_shared_policy(sp, &pvma, new); /* adds ref */ + mpol_put(new); /* drop initial ref */ + NODEMASK_SCRATCH_FREE(scratch); } } @@ -1832,7 +2014,7 @@ int mpol_set_shared_policy(struct shared_policy *info, pr_debug("set_shared_policy %lx sz %lu %d %d %lx\n", vma->vm_pgoff, - sz, npol ? npol->policy : -1, + sz, npol ? npol->mode : -1, npol ? npol->flags : -1, npol ? nodes_addr(npol->v.nodes)[0] : -1); @@ -1917,24 +2099,183 @@ void numa_default_policy(void) } /* - * Display pages allocated per node and memory policy via /proc. + * Parse and format mempolicy from/to strings */ -static const char * const policy_types[] = - { "default", "prefer", "bind", "interleave" }; /* + * "local" is pseudo-policy: MPOL_PREFERRED with MPOL_F_LOCAL flag + * Used only for mpol_parse_str() and mpol_to_str() + */ +#define MPOL_LOCAL (MPOL_INTERLEAVE + 1) +static const char * const policy_types[] = + { "default", "prefer", "bind", "interleave", "local" }; + + +#ifdef CONFIG_TMPFS +/** + * mpol_parse_str - parse string to mempolicy + * @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: + * [=][:] + * + * 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) +{ + struct mempolicy *new = NULL; + unsigned short uninitialized_var(mode); + unsigned short uninitialized_var(mode_flags); + nodemask_t nodes; + char *nodelist = strchr(str, ':'); + char *flags = strchr(str, '='); + int i; + int err = 1; + + if (nodelist) { + /* NUL-terminate mode or flags string */ + *nodelist++ = '\0'; + if (nodelist_parse(nodelist, nodes)) + goto out; + if (!nodes_subset(nodes, node_states[N_HIGH_MEMORY])) + goto out; + } else + nodes_clear(nodes); + + if (flags) + *flags++ = '\0'; /* terminate mode string */ + + for (i = 0; i <= MPOL_LOCAL; i++) { + if (!strcmp(str, policy_types[i])) { + mode = i; + break; + } + } + if (i > MPOL_LOCAL) + goto out; + + switch (mode) { + case MPOL_PREFERRED: + /* + * Insist on a nodelist of one node only + */ + if (nodelist) { + char *rest = nodelist; + while (isdigit(*rest)) + rest++; + if (!*rest) + err = 0; + } + break; + case MPOL_INTERLEAVE: + /* + * Default to online nodes with memory if no nodelist + */ + if (!nodelist) + nodes = node_states[N_HIGH_MEMORY]; + err = 0; + break; + case MPOL_LOCAL: + /* + * Don't allow a nodelist; mpol_new() checks flags + */ + if (nodelist) + goto out; + mode = MPOL_PREFERRED; + break; + + /* + * case MPOL_BIND: mpol_new() enforces non-empty nodemask. + * case MPOL_DEFAULT: mpol_new() enforces empty nodemask, ignores flags. + */ + } + + mode_flags = 0; + if (flags) { + /* + * Currently, we only support two mutually exclusive + * mode flags. + */ + if (!strcmp(flags, "static")) + mode_flags |= MPOL_F_STATIC_NODES; + else if (!strcmp(flags, "relative")) + mode_flags |= MPOL_F_RELATIVE_NODES; + else + err = 1; + } + + new = mpol_new(mode, mode_flags, &nodes); + if (IS_ERR(new)) + err = 1; + 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) { + err = 1; + mpol_put(new); + } else if (no_context) { + /* save for contextualization */ + new->w.user_nodemask = nodes; + } + } + +out: + /* Restore string for error message */ + if (nodelist) + *--nodelist = ':'; + if (flags) + *--flags = '='; + if (!err) + *mpol = new; + return err; +} +#endif /* CONFIG_TMPFS */ + +/** + * mpol_to_str - format a mempolicy structure for printing + * @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) */ -static inline int mpol_to_str(char *buffer, int maxlen, struct mempolicy *pol) +int mpol_to_str(char *buffer, int maxlen, struct mempolicy *pol, int no_context) { char *p = buffer; int l; nodemask_t nodes; - unsigned short mode = pol ? pol->policy : MPOL_DEFAULT; + unsigned short mode; unsigned short flags = pol ? pol->flags : 0; + /* + * Sanity check: room for longest mode, flag and some nodes + */ + VM_BUG_ON(maxlen < strlen("interleave") + strlen("relative") + 16); + + if (!pol || pol == &default_policy) + mode = MPOL_DEFAULT; + else + mode = pol->mode; + switch (mode) { case MPOL_DEFAULT: nodes_clear(nodes); @@ -1942,44 +2283,50 @@ static inline int mpol_to_str(char *buffer, int maxlen, struct mempolicy *pol) case MPOL_PREFERRED: nodes_clear(nodes); - node_set(pol->v.preferred_node, nodes); + if (flags & MPOL_F_LOCAL) + mode = MPOL_LOCAL; /* pseudo-policy */ + else + node_set(pol->v.preferred_node, nodes); break; case MPOL_BIND: /* Fall through */ case MPOL_INTERLEAVE: - nodes = pol->v.nodes; + if (no_context) + nodes = pol->w.user_nodemask; + else + nodes = pol->v.nodes; break; default: BUG(); - return -EFAULT; } l = strlen(policy_types[mode]); - if (buffer + maxlen < p + l + 1) - return -ENOSPC; + if (buffer + maxlen < p + l + 1) + return -ENOSPC; strcpy(p, policy_types[mode]); p += l; - if (flags) { - int need_bar = 0; - + if (flags & MPOL_MODE_FLAGS) { if (buffer + maxlen < p + 2) return -ENOSPC; *p++ = '='; + /* + * Currently, the only defined flags are mutually exclusive + */ if (flags & MPOL_F_STATIC_NODES) - p += sprintf(p, "%sstatic", need_bar++ ? "|" : ""); - if (flags & MPOL_F_RELATIVE_NODES) - p += sprintf(p, "%srelative", need_bar++ ? "|" : ""); + p += snprintf(p, buffer + maxlen - p, "static"); + else if (flags & MPOL_F_RELATIVE_NODES) + p += snprintf(p, buffer + maxlen - p, "relative"); } if (!nodes_empty(nodes)) { if (buffer + maxlen < p + 2) return -ENOSPC; - *p++ = '='; + *p++ = ':'; p += nodelist_scnprintf(p, buffer + maxlen - p, nodes); } return p - buffer; @@ -2008,7 +2355,7 @@ static void gather_stats(struct page *page, void *private, int pte_dirty) if (PageSwapCache(page)) md->swapcache++; - if (PageActive(page)) + if (PageActive(page) || PageUnevictable(page)) md->active++; if (PageWriteback(page)) @@ -2030,9 +2377,12 @@ static void check_huge_range(struct vm_area_struct *vma, { unsigned long addr; struct page *page; + struct hstate *h = hstate_vma(vma); + unsigned long sz = huge_page_size(h); - for (addr = start; addr < end; addr += HPAGE_SIZE) { - pte_t *ptep = huge_pte_offset(vma->vm_mm, addr & HPAGE_MASK); + for (addr = start; addr < end; addr += sz) { + pte_t *ptep = huge_pte_offset(vma->vm_mm, + addr & huge_page_mask(h)); pte_t pte; if (!ptep) @@ -2057,6 +2407,9 @@ static inline void check_huge_range(struct vm_area_struct *vma, } #endif +/* + * Display pages allocated per node and memory policy via /proc. + */ int show_numa_map(struct seq_file *m, void *v) { struct proc_maps_private *priv = m->private; @@ -2076,12 +2429,8 @@ int show_numa_map(struct seq_file *m, void *v) return 0; pol = get_vma_policy(priv->task, vma, vma->vm_start); - mpol_to_str(buffer, sizeof(buffer), pol); - /* - * unref shared or other task's mempolicy - */ - if (pol != &default_policy && pol != current->mempolicy) - __mpol_put(pol); + mpol_to_str(buffer, sizeof(buffer), pol, 0); + mpol_cond_put(pol); seq_printf(m, "%08lx %s", vma->vm_start, buffer);