On Wed, May 20, 2020 at 11:15:02AM +0800, Huang Ying wrote:
> @@ -2827,6 +2865,11 @@ static struct swap_info_struct *alloc_swap_info(void)
> p = kvzalloc(struct_size(p, avail_lists, nr_node_ids), GFP_KERNEL);
> if (!p)
> return ERR_PTR(-ENOMEM);
> + p->cluster_next_cpu = alloc_percpu(unsigned int);
> + if (!p->cluster_next_cpu) {
> + kvfree(p);
> + return ERR_PTR(-ENOMEM);
> + }
There should be free_percpu()s at two places after this, but I think the
allocation really belongs right...
> @@ -3202,7 +3245,10 @@ SYSCALL_DEFINE2(swapon, const char __user *,
> specialfile, int, swap_flags)
> * select a random position to start with to help wear leveling
> * SSD
> */
> - p->cluster_next = 1 + prandom_u32_max(p->highest_bit);
...here because then it's only allocated when it's actually used.
> + for_each_possible_cpu(cpu) {
> + per_cpu(*p->cluster_next_cpu, cpu) =
> + 1 + prandom_u32_max(p->highest_bit);
> + }
> nr_cluster = DIV_ROUND_UP(maxpages, SWAPFILE_CLUSTER);
>
> cluster_info = kvcalloc(nr_cluster, sizeof(*cluster_info),
> --
> 2.26.2
>
>
