On Mon, Aug 21, 2023 at 05:20:51PM +0300, Anastasia Belova wrote: > kzalloc_node may return NULL. So rtpn should be > checked before dereference in mem_cgroup_init. What good will this do? > > rtpn = kzalloc_node(sizeof(*rtpn), GFP_KERNEL, node); > + WARN_ON(!rtpn); > > rtpn->rb_root = RB_ROOT; so you'll get a warning right before you get a crash, which will provide exactly the same information. And you'd already have a warning that the memory allocation had failed (because __GFP_NOWARN wasn't set). So you've increased the amount of data from 2 dumps to 3 without providing any neww information. If you _did_ something to avoid the crash, there might be a point to this, but the fact is that small GFP_KERNEL allocations _don't_ fail. You need to teach your tool that, or you'll be overwhelmed with false positives.
