Matthew Dobson <colpatch@us.ibm.com> wrote:
>
> +#define __NR_mbind 223
What was wrong with "membind"?
> +/* Translate a cpumask to a nodemask */
> +static inline void cpumask_to_nodemask(bitmap_t cpumask, bitmap_t nodemask)
> +{
> + int i;
> +
> + for (i = 0; i < NR_CPUS; i++)
> + if (test_bit(i, cpumask))
That's a bit weird. test_bit is only permitted on longs, so why introduce
bitmap_t?
> +/* Top-level function for allocating a binding for a region of memory */
> +static inline struct binding *alloc_binding(bitmap_t nodemask)
> +{
> + struct binding *binding;
> + int node, zone_num;
> +
> + binding = (struct binding *)kmalloc(sizeof(struct binding), GFP_KERNEL);
> + if (!binding)
> + return NULL;
> + memset(binding, 0, sizeof(struct binding));
> +
> + /* Build binding zonelist */
> + for (node = 0, zone_num = 0; node < MAX_NUMNODES; node++)
> + if (test_bit(node, nodemask) && node_online(node))
> + zone_num = add_node(NODE_DATA(node),
> + &binding->zonelist, zone_num);
> + binding->zonelist.zones[zone_num] = NULL;
> +
> + if (zone_num == 0) {
> + /* No zones were added to the zonelist. Let the caller know. */
> + kfree(binding);
> + binding = NULL;
> + }
> + return binding;
> +}
It looks like this function needs to be able to return a real errno (see
below).
> +asmlinkage unsigned long sys_mbind(unsigned long start, unsigned long len,
> + unsigned long *mask_ptr, unsigned int mask_len, unsigned long policy)
> +{
> + DECLARE_BITMAP(cpu_mask, NR_CPUS);
> + DECLARE_BITMAP(node_mask, MAX_NUMNODES);
Bah. Who cooked that up? It should be DEFINE_BITMAP. Oh well.
> + struct vm_area_struct *vma = NULL;
> + struct address_space *mapping;
> + int copy_len, error = 0;
> +
> + /* Deal with getting cpu_mask from userspace & translating to node_mask */
> + copy_len = min(mask_len, (unsigned int)NR_CPUS);
> + CLEAR_BITMAP(cpu_mask, NR_CPUS);
> + CLEAR_BITMAP(node_mask, MAX_NUMNODES);
> + if (copy_from_user(cpu_mask, mask_ptr, (copy_len+7)/8)) {
> + error = -EFAULT;
> + goto out;
> + }
> + cpumask_to_nodemask(cpu_mask, node_mask);
> +
> + vma = find_vma(current->mm, start);
> + if (!(vma && vma->vm_file && vma->vm_ops &&
> + vma->vm_ops->nopage == shmem_nopage)) {
> + /* This isn't a shm segment. For now, we bail. */
> + error = -EINVAL;
> + goto out;
> + }
> +
> + mapping = vma->vm_file->f_dentry->d_inode->i_mapping;
> + mapping->binding = alloc_binding(node_mask);
> + if (!mapping->binding)
> + error = -EFAULT;
It returns EFAULT on memory exhaustion?
btw, can you remind me again why this is only available to tmpfs pagecache?
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This archive was generated by hypermail 2b29 : Mon Apr 07 2003 - 22:00:19 EST