X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=mm%2Fmempolicy.c;h=008fb32936ebfbc99ff737ff66ff177243c8a930;hb=3193913ce62c63056bc67a6ae378beaf494afa66;hp=8f5330d74f47bded6c1119b49fe34c2ba2573029;hpb=8d2d441ac4af223eae466c3c31ff737cc31a1411;p=firefly-linux-kernel-4.4.55.git diff --git a/mm/mempolicy.c b/mm/mempolicy.c index 8f5330d74f47..008fb32936eb 100644 --- a/mm/mempolicy.c +++ b/mm/mempolicy.c @@ -123,25 +123,23 @@ static struct mempolicy default_policy = { static struct mempolicy preferred_node_policy[MAX_NUMNODES]; -static struct mempolicy *get_task_policy(struct task_struct *p) +struct mempolicy *get_task_policy(struct task_struct *p) { struct mempolicy *pol = p->mempolicy; + int node; - if (!pol) { - int node = numa_node_id(); + if (pol) + return pol; - if (node != NUMA_NO_NODE) { - pol = &preferred_node_policy[node]; - /* - * preferred_node_policy is not initialised early in - * boot - */ - if (!pol->mode) - pol = NULL; - } + node = numa_node_id(); + if (node != NUMA_NO_NODE) { + pol = &preferred_node_policy[node]; + /* preferred_node_policy is not initialised early in boot */ + if (pol->mode) + return pol; } - return pol; + return &default_policy; } static const struct mempolicy_operations { @@ -804,7 +802,6 @@ static long do_set_mempolicy(unsigned short mode, unsigned short flags, nodemask_t *nodes) { struct mempolicy *new, *old; - struct mm_struct *mm = current->mm; NODEMASK_SCRATCH(scratch); int ret; @@ -816,20 +813,11 @@ static long do_set_mempolicy(unsigned short mode, unsigned short flags, ret = PTR_ERR(new); goto out; } - /* - * prevent changing our mempolicy while show_numa_maps() - * is using it. - * Note: do_set_mempolicy() can be called at init time - * with no 'mm'. - */ - if (mm) - down_write(&mm->mmap_sem); + 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; } @@ -839,9 +827,6 @@ static long do_set_mempolicy(unsigned short mode, unsigned short flags, nodes_weight(new->v.nodes)) current->il_next = first_node(new->v.nodes); task_unlock(current); - if (mm) - up_write(&mm->mmap_sem); - mpol_put(old); ret = 0; out: @@ -1605,32 +1590,14 @@ COMPAT_SYSCALL_DEFINE6(mbind, compat_ulong_t, start, compat_ulong_t, len, #endif -/* - * get_vma_policy(@task, @vma, @addr) - * @task: task for fallback if vma policy == default - * @vma: virtual memory area whose policy is sought - * @addr: address in @vma for shared policy lookup - * - * Returns effective policy for a VMA at specified address. - * Falls back to @task or system default policy, as necessary. - * Current or other task's task mempolicy and non-shared vma policies must be - * protected by task_lock(task) 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. - */ -struct mempolicy *get_vma_policy(struct task_struct *task, - struct vm_area_struct *vma, unsigned long addr) +struct mempolicy *__get_vma_policy(struct vm_area_struct *vma, + unsigned long addr) { - struct mempolicy *pol = get_task_policy(task); + struct mempolicy *pol = NULL; if (vma) { if (vma->vm_ops && vma->vm_ops->get_policy) { - struct mempolicy *vpol = vma->vm_ops->get_policy(vma, - addr); - if (vpol) - pol = vpol; + pol = vma->vm_ops->get_policy(vma, addr); } else if (vma->vm_policy) { pol = vma->vm_policy; @@ -1644,31 +1611,51 @@ struct mempolicy *get_vma_policy(struct task_struct *task, mpol_get(pol); } } + + return pol; +} + +/* + * get_vma_policy(@vma, @addr) + * @vma: virtual memory area whose policy is sought + * @addr: address in @vma for shared policy lookup + * + * Returns effective policy for a VMA at specified address. + * Falls back to current->mempolicy or system default policy, as necessary. + * 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 vm_area_struct *vma, + unsigned long addr) +{ + struct mempolicy *pol = __get_vma_policy(vma, addr); + if (!pol) - pol = &default_policy; + pol = get_task_policy(current); + return pol; } -bool vma_policy_mof(struct task_struct *task, struct vm_area_struct *vma) +bool vma_policy_mof(struct vm_area_struct *vma) { - struct mempolicy *pol = get_task_policy(task); - if (vma) { - if (vma->vm_ops && vma->vm_ops->get_policy) { - bool ret = false; + struct mempolicy *pol; - pol = vma->vm_ops->get_policy(vma, vma->vm_start); - if (pol && (pol->flags & MPOL_F_MOF)) - ret = true; - mpol_cond_put(pol); + if (vma->vm_ops && vma->vm_ops->get_policy) { + bool ret = false; - return ret; - } else if (vma->vm_policy) { - pol = vma->vm_policy; - } + pol = vma->vm_ops->get_policy(vma, vma->vm_start); + if (pol && (pol->flags & MPOL_F_MOF)) + ret = true; + mpol_cond_put(pol); + + return ret; } + pol = vma->vm_policy; if (!pol) - return default_policy.flags & MPOL_F_MOF; + pol = get_task_policy(current); return pol->flags & MPOL_F_MOF; } @@ -1874,7 +1861,7 @@ struct zonelist *huge_zonelist(struct vm_area_struct *vma, unsigned long addr, { struct zonelist *zl; - *mpol = get_vma_policy(current, vma, addr); + *mpol = get_vma_policy(vma, addr); *nodemask = NULL; /* assume !MPOL_BIND */ if (unlikely((*mpol)->mode == MPOL_INTERLEAVE)) { @@ -2029,7 +2016,7 @@ alloc_pages_vma(gfp_t gfp, int order, struct vm_area_struct *vma, unsigned int cpuset_mems_cookie; retry_cpuset: - pol = get_vma_policy(current, vma, addr); + pol = get_vma_policy(vma, addr); cpuset_mems_cookie = read_mems_allowed_begin(); if (unlikely(pol->mode == MPOL_INTERLEAVE)) { @@ -2046,8 +2033,7 @@ retry_cpuset: page = __alloc_pages_nodemask(gfp, order, policy_zonelist(gfp, pol, node), policy_nodemask(gfp, pol)); - if (unlikely(mpol_needs_cond_ref(pol))) - __mpol_put(pol); + mpol_cond_put(pol); if (unlikely(!page && read_mems_allowed_retry(cpuset_mems_cookie))) goto retry_cpuset; return page; @@ -2074,12 +2060,12 @@ retry_cpuset: */ struct page *alloc_pages_current(gfp_t gfp, unsigned order) { - struct mempolicy *pol = get_task_policy(current); + struct mempolicy *pol = &default_policy; struct page *page; unsigned int cpuset_mems_cookie; - if (!pol || in_interrupt() || (gfp & __GFP_THISNODE)) - pol = &default_policy; + if (!in_interrupt() && !(gfp & __GFP_THISNODE)) + pol = get_task_policy(current); retry_cpuset: cpuset_mems_cookie = read_mems_allowed_begin(); @@ -2296,7 +2282,7 @@ int mpol_misplaced(struct page *page, struct vm_area_struct *vma, unsigned long BUG_ON(!vma); - pol = get_vma_policy(current, vma, addr); + pol = get_vma_policy(vma, addr); if (!(pol->flags & MPOL_F_MOF)) goto out;