Re: [RFC PATCH bpf-next v3 12/12] samples/bpf: Add memcg priority control example
From: bot+bpf-ci@kernel.org
Date: 2026-01-23 09:19:01
Also in:
bpf, cgroups, linux-kselftest, linux-mm, lkml
quoted hunk ↗ jump to hunk
diff --git a/samples/bpf/Makefile b/samples/bpf/Makefile index 95a4fa1f1e44..6416c8aa3034 100644
[ ... ]
quoted hunk ↗ jump to hunk
@@ -360,6 +366,7 @@ BPF_SKELS_LINKED := $(addprefix $(obj)/,$(LINKED_SKELS)) $(BPF_SKELS_LINKED): $(BPF_OBJS_LINKED) $(BPFTOOL) @echo " BPF GEN-OBJ " $(@:.skel.h=) + echo $(Q)$(BPFTOOL) gen object $(@:.skel.h=.lbpf.o) $(addprefix $(obj)/,$($(@F)-deps)) $(Q)$(BPFTOOL) gen object $(@:.skel.h=.lbpf.o) $(addprefix $(obj)/,$($(@F)-deps))
Was this debug echo intended to be left in? The line without the @ prefix will print the unexpanded command during the build, which looks like leftover debug output.
quoted hunk ↗ jump to hunk
diff --git a/samples/bpf/memcg.c b/samples/bpf/memcg.c new file mode 100644 index 000000000000..85432cb01c27 --- /dev/null +++ b/samples/bpf/memcg.c
[ ... ]
+ high_cgroup_id = get_cgroup_id(high_path);
+ if (!high_cgroup_id)
+ goto out;
+ high_cgroup_fd = open(high_path, O_RDONLY);
+ if (high_cgroup_fd < 0) {
+ fprintf(stderr,
+ "ERROR: open high cgroup '%s' failed: %d\n",
+ low_path, errno);^^^^^^^^ Should this be high_path instead of low_path? The error message says "open high cgroup" but prints low_path. [ ... ]
+ struct bpf_link *link = NULL, *link_low = NULL, *link_high = NULL;
[ ... ]
+ if (over_high_ms) {[ ... ]
+ link_low = bpf_map__attach_struct_ops_opts(map, &opts);
[ ... ]
+ if (use_below_low || use_below_min) {
+ map = bpf_object__find_map_by_name(obj, "high_mcg_ops");[ ... ]
+ link_low = bpf_map__attach_struct_ops_opts(map, &opts);
^^^^^^^^ This assigns to link_low again, overwriting the previous link if both over_high_ms and (use_below_low || use_below_min) are set. Should this be link_high instead? The link_high variable is declared but never assigned, and the first bpf_link would be leaked in this scenario. [ ... ]
+out: + bpf_link__destroy(link); + bpf_link__destroy(link_low); + bpf_link__destroy(link_high);
Here link_high is always NULL since it was never assigned above. --- AI reviewed your patch. Please fix the bug or email reply why it's not a bug. See: https://github.com/kernel-patches/vmtest/blob/master/ci/claude/README.md CI run summary: https://github.com/kernel-patches/bpf/actions/runs/21280790825