On Fri, May 20, 2022 at 01:21:33AM +0000, Yosry Ahmed <yosryahmed@xxxxxxxxxx> wrote: > +#define CGROUP_PATH(p, n) {.name = #n, .path = #p"/"#n} > + > +static struct { > + const char *name, *path; Please unify the order of path and name with the macro (slightly confusing ;-). > +SEC("tp_btf/mm_vmscan_memcg_reclaim_end") > +int BPF_PROG(vmscan_end, struct lruvec *lruvec, struct scan_control *sc) > +{ > [...] > + struct cgroup *cgrp = task_memcg(current); > [...] > + /* cgrp may not have memory controller enabled */ > + if (!cgrp) > + return 0; Yes, the controller may not be enabled (for a cgroup). Just noting that the task_memcg() implementation will fall back to root_mem_cgroup in such a case (or nearest ancestor), you may want to use cgroup_ss_mask() for proper detection. Regards, Michal