mm/zswap: NUMA aware allocation for zswap_dstmem

zswap_dstmem is a percpu block of memory, which should be allocated using
kmalloc_node(), to get better NUMA locality.

Without it, all the blocks are allocated from a single node.

Signed-off-by: Eric Dumazet <[e-mail]>
Acked-by: Seth Jennings <[e-mail]>
Acked-by: David Rientjes <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
Signed-off-by: Linus Torvalds <[e-mail]>

mm/zswap.c

···
 			return NOTIFY_BAD;
 		}
 		*per_cpu_ptr(zswap_comp_pcpu_tfms, cpu) = tfm;
-		dst = kmalloc(PAGE_SIZE * 2, GFP_KERNEL);
+		dst = kmalloc_node(PAGE_SIZE * 2, GFP_KERNEL, cpu_to_node(cpu));
 		if (!dst) {
 			pr_err("can't allocate compressor buffer\n");
 			crypto_free_comp(tfm);