oomd: make it more clear when a kill happens

Improve the logging to only print if systemd-oomd killed something. And
also print which cgroup was targeted.
Demote general swap above/pressure above messages to debug.

[zjs: fix some issuelets found in review]

1 files changed, 4 insertions, 3 deletions

diff --git a/src/oom/oomd-util.h b/src/oom/oomd-util.h
index 560697a4f4..51423130d1 100644
--- a/src/oom/oomd-util.h
+++ b/src/oom/oomd-util.h
@@ -122,9 +122,10 @@ int oomd_cgroup_kill(const char *path, bool recurse, bool dry_run);
 
 /* The following oomd_kill_by_* functions return 1 if processes were killed, or negative otherwise. */
 /* If `prefix` is supplied, only cgroups whose paths start with `prefix` are eligible candidates. Otherwise,
- * everything in `h` is a candidate. */
-int oomd_kill_by_pgscan_rate(Hashmap *h, const char *prefix, bool dry_run);
-int oomd_kill_by_swap_usage(Hashmap *h, bool dry_run);
+ * everything in `h` is a candidate.
+ * Returns the killed cgroup in ret_selected. */
+int oomd_kill_by_pgscan_rate(Hashmap *h, const char *prefix, bool dry_run, char **ret_selected);
+int oomd_kill_by_swap_usage(Hashmap *h, bool dry_run, char **ret_selected);
 
 int oomd_cgroup_context_acquire(const char *path, OomdCGroupContext **ret);
 int oomd_system_context_acquire(const char *proc_swaps_path, OomdSystemContext *ret);