manager: free the jobs hashmap after we have no jobs

After a larger transaction, e.g. after bootup, we're left with an empty hashmap
with hundreds of buckets. Long-term, it'd be better to size hashmaps down when
they are less than 1/4 full, but even if we implement that, jobs hashmap is
likely to be empty almost always, so it seems useful to deallocate it once the
jobs count reaches 0.

1 files changed, 4 insertions, 0 deletions

diff --git a/src/core/job.c b/src/core/job.c
index cf3bca88d6..d518ac8969 100644
--- a/src/core/job.c
+++ b/src/core/job.c
@@ -263,6 +263,10 @@ int job_install_deserialized(Job *j) {
                 return log_unit_debug_errno(j->unit, SYNTHETIC_ERRNO(EEXIST),
                                             "Unit already has a job installed. Not installing deserialized job.");
 
+        r = hashmap_ensure_allocated(&j->manager->jobs, NULL);
+        if (r < 0)
+                return r;
+
         r = hashmap_put(j->manager->jobs, UINT32_TO_PTR(j->id), j);
         if (r == -EEXIST)
                 return log_unit_debug_errno(j->unit, r, "Job ID %" PRIu32 " already used, cannot deserialize job.", j->id);