From: Michael Tremer <michael.tremer@ipfire.org>
Date: Wed, 22 Oct 2025 10:37:37 +0000 (+0000)
Subject: daemon: Release memory when the system is under pressure
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=c88f973e0a13121f7ddfb4c6021de593a7d8dc44;p=telemetry.git

daemon: Release memory when the system is under pressure

Signed-off-by: Michael Tremer <michael.tremer@ipfire.org>
---

diff --git a/src/daemon/daemon.c b/src/daemon/daemon.c
index fab73f1..3ea05f3 100644
--- a/src/daemon/daemon.c
+++ b/src/daemon/daemon.c
@@ -53,6 +53,7 @@ struct td_daemon {
 		sd_event_source* sigchld;
 		sd_event_source* init;
 		sd_event_source* exit;
+		sd_event_source* memory_pressure;
 	} events;
 
 	// Bus
@@ -132,6 +133,25 @@ static int td_daemon_SIGCHLD(sd_event_source* source,
 	return 0;
 }
 
+static int td_daemon_release_memory(sd_event_source* source, void* data) {
+	td_daemon* self = data;
+	int r;
+
+	DEBUG(self->ctx, "Releasing memory...\n");
+
+	// Flush the queue to disk to free up memory
+	if (self->queue) {
+		r = td_queue_flush(self->queue);
+		if (r < 0) {
+			ERROR(self->ctx, "Failed to flush queue to release memory: %s\n", strerror(-r));
+			return r;
+		}
+	}
+
+	// Call the default operation
+	return sd_event_trim_memory();
+}
+
 static int td_daemon_setup_loop(td_daemon* self) {
 	int r;
 
@@ -195,6 +215,14 @@ static int td_daemon_setup_loop(td_daemon* self) {
 		return r;
 	}
 
+	// Release memory when asked to
+	r = sd_event_add_memory_pressure(self->loop, &self->events.memory_pressure,
+			td_daemon_release_memory, daemon);
+	if (r < 0) {
+		ERROR(self->ctx, "Failed to register memory pressure callback: %s\n", strerror(-r));
+		return r;
+	}
+
 	return 0;
 }
 
@@ -213,6 +241,8 @@ static int td_daemon_setup_udev(td_daemon* self) {
 }
 
 static void td_daemon_free(td_daemon* self) {
+	if (self->events.memory_pressure)
+		sd_event_source_unref(self->events.memory_pressure);
 	if (self->events.sigchld)
 		sd_event_source_unref(self->events.sigchld);
 	if (self->events.sigterm)