On 12/7/21 18:34, Matthew Wilcox wrote:
> On Tue, Dec 07, 2021 at 05:40:13PM -0500, Nico Pache wrote:
>> +++ b/mm/vmscan.c
>> @@ -222,13 +222,16 @@ static int expand_one_shrinker_info(struct mem_cgroup *memcg,
>> int size = map_size + defer_size;
>>
>> for_each_node(nid) {
>> + int tmp = nid;
>> pn = memcg->nodeinfo[nid];
>> old = shrinker_info_protected(memcg, nid);
>> /* Not yet online memcg */
>> if (!old)
>> return 0;
>>
>> - new = kvmalloc_node(sizeof(*new) + size, GFP_KERNEL, nid);
>> + if(!node_online(nid))
>> + tmp = numa_mem_id();
>> + new = kvmalloc_node(sizeof(*new) + size, GFP_KERNEL, tmp);
>> if (!new)
>
> Why should this be fixed here and not in, say, kvmalloc_node()?
according to Michal, the caller should be responsible for making sure it is
allocating on a correct node. This avoids adding branches to hot-paths and
wasting cycles. Im not opposed to moving it to kvmalloc_node, but it may result
in masking other issues from other callers.
>
