On Fri, Jan 14, 2022 at 09:51:31AM +0100, Michal Hocko wrote: >On Fri 14-01-22 00:29:37, Wei Yang wrote: >> On Wed, Jan 12, 2022 at 09:56:15AM +0100, Michal Hocko wrote: >> >On Wed 12-01-22 00:46:34, Wei Yang wrote: >> >> On Tue, Jan 11, 2022 at 09:40:20AM +0100, Michal Hocko wrote: >> >> >On Tue 11-01-22 01:02:59, Wei Yang wrote: >> >> >> Instead of use "-1", let's use NUMA_NO_NODE for consistency. >> >> >> >> >> >> Signed-off-by: Wei Yang <richard.weiyang@xxxxxxxxx> >> >> > >> >> >I am not really sure this is worth it. After the merge window I plan to >> >> >post http://lkml.kernel.org/r/20211214100732.26335-1-mhocko@xxxxxxxxxx. >> >> >> >> Give me some time to understand it :-) >> > >> >Just for the record, here is what I have put on top of that series: >> >> Ok, I got what you try to resolve. I am ok with the following change except >> one point. >> >> >--- >> >>From b7195eba02fe6308a6927450f4630057c05e808e Mon Sep 17 00:00:00 2001 >> >From: Wei Yang <richard.weiyang@xxxxxxxxx> >> >Date: Tue, 11 Jan 2022 09:45:25 +0100 >> >Subject: [PATCH] memcg: do not tweak node in alloc_mem_cgroup_per_node_info >> > >> >alloc_mem_cgroup_per_node_info is allocated for each possible node and >> >this used to be a problem because not !node_online nodes didn't have >> >appropriate data structure allocated. This has changed by "mm: handle >> >uninitialized numa nodes gracefully" so we can drop the special casing >> >here. >> > >> >Signed-off-by: Wei Yang <richard.weiyang@xxxxxxxxx> >> >Signed-off-by: Michal Hocko <mhocko@xxxxxxxx> >> >--- >> > mm/memcontrol.c | 14 ++------------ >> > 1 file changed, 2 insertions(+), 12 deletions(-) >> > >> >diff --git a/mm/memcontrol.c b/mm/memcontrol.c >> >index 781605e92015..ed19a21ee14e 100644 >> >--- a/mm/memcontrol.c >> >+++ b/mm/memcontrol.c >> >@@ -5044,18 +5044,8 @@ struct mem_cgroup *mem_cgroup_from_id(unsigned short id) >> > static int alloc_mem_cgroup_per_node_info(struct mem_cgroup *memcg, int node) >> > { >> > struct mem_cgroup_per_node *pn; >> >- int tmp = node; >> >- /* >> >- * This routine is called against possible nodes. >> >- * But it's BUG to call kmalloc() against offline node. >> >- * >> >- * TODO: this routine can waste much memory for nodes which will >> >- * never be onlined. It's better to use memory hotplug callback >> >- * function. >> >- */ >> >> Do you think this TODO is not related to this change? > >It is not really related but I am not sure how useful it is. Essentially >any allocation that is per-possible node is in the same situation and if >we really need to deal with large and sparse possible nodes masks. > Sounds reasonable :-) >If you want me to keep the TODO I will do it though. > >-- >Michal Hocko >SUSE Labs -- Wei Yang Help you, Help me
