daandemeyer / rpms / systemd

Forked from rpms/systemd 2 years ago
Clone
ff6046
From 0412acb95ffac94d5916ee19991cc7194e55953c Mon Sep 17 00:00:00 2001
ff6046
From: Lennart Poettering <lennart@poettering.net>
ff6046
Date: Tue, 13 Nov 2018 12:48:49 +0100
ff6046
Subject: [PATCH] core: make sure we don't throttle change signal generator
ff6046
 when a reload is pending
ff6046
ff6046
Fixes: #10627
ff6046
(cherry picked from commit b8d381c47776ea0440af175cbe0c02cb743bde08)
ff6046
ff6046
Resolves: #1647359
ff6046
---
ff6046
 src/core/manager.c | 64 ++++++++++++++++++++++++++++------------------
ff6046
 1 file changed, 39 insertions(+), 25 deletions(-)
ff6046
ff6046
diff --git a/src/core/manager.c b/src/core/manager.c
ff6046
index a24bfcacdf..3b2fe11e87 100644
ff6046
--- a/src/core/manager.c
ff6046
+++ b/src/core/manager.c
ff6046
@@ -2074,56 +2074,70 @@ static unsigned manager_dispatch_dbus_queue(Manager *m) {
ff6046
 
ff6046
         assert(m);
ff6046
 
ff6046
+        /* Avoid recursion */
ff6046
         if (m->dispatching_dbus_queue)
ff6046
                 return 0;
ff6046
 
ff6046
-        /* Anything to do at all? */
ff6046
-        if (!m->dbus_unit_queue && !m->dbus_job_queue && !m->send_reloading_done && !m->pending_reload_message)
ff6046
-                return 0;
ff6046
+        /* When we are reloading, let's not wait with generating signals, since we need to exit the manager as quickly
ff6046
+         * as we can. There's no point in throttling generation of signals in that case. */
ff6046
+        if (MANAGER_IS_RELOADING(m) || m->send_reloading_done || m->pending_reload_message)
ff6046
+                budget = (unsigned) -1; /* infinite budget in this case */
ff6046
+        else {
ff6046
+                /* Anything to do at all? */
ff6046
+                if (!m->dbus_unit_queue && !m->dbus_job_queue)
ff6046
+                        return 0;
ff6046
 
ff6046
-        /* Do we have overly many messages queued at the moment? If so, let's not enqueue more on top, let's sit this
ff6046
-         * cycle out, and process things in a later cycle when the queues got a bit emptier. */
ff6046
-        if (manager_bus_n_queued_write(m) > MANAGER_BUS_BUSY_THRESHOLD)
ff6046
-                return 0;
ff6046
+                /* Do we have overly many messages queued at the moment? If so, let's not enqueue more on top, let's
ff6046
+                 * sit this cycle out, and process things in a later cycle when the queues got a bit emptier. */
ff6046
+                if (manager_bus_n_queued_write(m) > MANAGER_BUS_BUSY_THRESHOLD)
ff6046
+                        return 0;
ff6046
 
ff6046
-        /* Only process a certain number of units/jobs per event loop iteration. Even if the bus queue wasn't overly
ff6046
-         * full before this call we shouldn't increase it in size too wildly in one step, and we shouldn't monopolize
ff6046
-         * CPU time with generating these messages. Note the difference in counting of this "budget" and the
ff6046
-         * "threshold" above: the "budget" is decreased only once per generated message, regardless how many
ff6046
-         * busses/direct connections it is enqueued on, while the "threshold" is applied to each queued instance of bus
ff6046
-         * message, i.e. if the same message is enqueued to five busses/direct connections it will be counted five
ff6046
-         * times. This difference in counting ("references" vs. "instances") is primarily a result of the fact that
ff6046
-         * it's easier to implement it this way, however it also reflects the thinking that the "threshold" should put
ff6046
-         * a limit on used queue memory, i.e. space, while the "budget" should put a limit on time. Also note that
ff6046
-         * the "threshold" is currently chosen much higher than the "budget". */
ff6046
-        budget = MANAGER_BUS_MESSAGE_BUDGET;
ff6046
+                /* Only process a certain number of units/jobs per event loop iteration. Even if the bus queue wasn't
ff6046
+                 * overly full before this call we shouldn't increase it in size too wildly in one step, and we
ff6046
+                 * shouldn't monopolize CPU time with generating these messages. Note the difference in counting of
ff6046
+                 * this "budget" and the "threshold" above: the "budget" is decreased only once per generated message,
ff6046
+                 * regardless how many busses/direct connections it is enqueued on, while the "threshold" is applied to
ff6046
+                 * each queued instance of bus message, i.e. if the same message is enqueued to five busses/direct
ff6046
+                 * connections it will be counted five times. This difference in counting ("references"
ff6046
+                 * vs. "instances") is primarily a result of the fact that it's easier to implement it this way,
ff6046
+                 * however it also reflects the thinking that the "threshold" should put a limit on used queue memory,
ff6046
+                 * i.e. space, while the "budget" should put a limit on time. Also note that the "threshold" is
ff6046
+                 * currently chosen much higher than the "budget". */
ff6046
+                budget = MANAGER_BUS_MESSAGE_BUDGET;
ff6046
+        }
ff6046
 
ff6046
         m->dispatching_dbus_queue = true;
ff6046
 
ff6046
-        while (budget > 0 && (u = m->dbus_unit_queue)) {
ff6046
+        while (budget != 0 && (u = m->dbus_unit_queue)) {
ff6046
 
ff6046
                 assert(u->in_dbus_queue);
ff6046
 
ff6046
                 bus_unit_send_change_signal(u);
ff6046
-                n++, budget--;
ff6046
+                n++;
ff6046
+
ff6046
+                if (budget != (unsigned) -1)
ff6046
+                        budget--;
ff6046
         }
ff6046
 
ff6046
-        while (budget > 0 && (j = m->dbus_job_queue)) {
ff6046
+        while (budget != 0 && (j = m->dbus_job_queue)) {
ff6046
                 assert(j->in_dbus_queue);
ff6046
 
ff6046
                 bus_job_send_change_signal(j);
ff6046
-                n++, budget--;
ff6046
+                n++;
ff6046
+
ff6046
+                if (budget != (unsigned) -1)
ff6046
+                        budget--;
ff6046
         }
ff6046
 
ff6046
         m->dispatching_dbus_queue = false;
ff6046
 
ff6046
-        if (budget > 0 && m->send_reloading_done) {
ff6046
+        if (m->send_reloading_done) {
ff6046
                 m->send_reloading_done = false;
ff6046
                 bus_manager_send_reloading(m, false);
ff6046
-                n++, budget--;
ff6046
+                n++;
ff6046
         }
ff6046
 
ff6046
-        if (budget > 0 && m->pending_reload_message) {
ff6046
+        if (m->pending_reload_message) {
ff6046
                 bus_send_pending_reload_message(m);
ff6046
                 n++;
ff6046
         }