From: Luca Boccassi <luca.boccassi@microsoft.com>
Date: Tue, 21 Apr 2020 16:28:01 +0000 (+0100)
Subject: core: add debug log when a job in the activation queue is not runnable
X-Git-Tag: v246-rc1~535^2
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=refs%2Fpull%2F15526%2Fhead;p=thirdparty%2Fsystemd.git

core: add debug log when a job in the activation queue is not runnable

When a job is skipped due its dependencies not being ready, log
a debug message saying what is holding it back.
This was very useful with transient units timing out to figure
out where the problem was.
---

diff --git a/src/core/job.c b/src/core/job.c
index 2114889d326..cf3bca88d63 100644
--- a/src/core/job.c
+++ b/src/core/job.c
@@ -516,12 +516,20 @@ static bool job_is_runnable(Job *j) {
                 return true;
 
         HASHMAP_FOREACH_KEY(v, other, j->unit->dependencies[UNIT_AFTER], i)
-                if (other->job && job_compare(j, other->job, UNIT_AFTER) > 0)
+                if (other->job && job_compare(j, other->job, UNIT_AFTER) > 0) {
+                        log_unit_debug(j->unit,
+                                       "starting held back, waiting for: %s",
+                                       other->id);
                         return false;
+                }
 
         HASHMAP_FOREACH_KEY(v, other, j->unit->dependencies[UNIT_BEFORE], i)
-                if (other->job && job_compare(j, other->job, UNIT_BEFORE) > 0)
+                if (other->job && job_compare(j, other->job, UNIT_BEFORE) > 0) {
+                        log_unit_debug(j->unit,
+                                       "stopping held back, waiting for: %s",
+                                       other->id);
                         return false;
+                }
 
         return true;
 }