From a2fae8666985d0b4f4dbc157b603327a8594600c Mon Sep 17 00:00:00 2001
From: Nathan Bossart <bossartn@amazon.com>
Date: Fri, 11 Dec 2020 18:51:10 +0000
Subject: [PATCH v8 1/1] Add checkpoint/restartpoint status to ps display.

---
 src/backend/access/transam/xlog.c | 37 +++++++++++++++++++++++++++++++++++++
 1 file changed, 37 insertions(+)

diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c
index 7e81ce4f17..7f8934cfb8 100644
--- a/src/backend/access/transam/xlog.c
+++ b/src/backend/access/transam/xlog.c
@@ -8687,6 +8687,31 @@ UpdateCheckPointDistanceEstimate(uint64 nbytes)
 			(0.90 * CheckPointDistanceEstimate + 0.10 * (double) nbytes);
 }
 
+/*
+ * Update the ps display for a process running a checkpoint or restartpoint.
+ * Note that this routine cannot do any memory allocations, since it may be
+ * called within a critical section.
+ */
+static void
+set_ps_display_for_checkpoint(int flags, bool restartpoint)
+{
+	char activitymsg[128];
+
+	/*
+	 * The status is reported only for end-of-recovery/shutdown checkpoints and
+	 * shutdown restartpoints since it may not be possible to access
+	 * pg_stat_activity in those situations.
+	 */
+	if ((flags & (CHECKPOINT_END_OF_RECOVERY | CHECKPOINT_IS_SHUTDOWN)) == 0)
+		return;
+
+	snprintf(activitymsg, sizeof(activitymsg), "performing %s%s%s",
+			 (flags & CHECKPOINT_END_OF_RECOVERY) ? "end-of-recovery " : "",
+			 (flags & CHECKPOINT_IS_SHUTDOWN) ? "shutdown " : "",
+			 restartpoint ? "restartpoint" : "checkpoint");
+	set_ps_display(activitymsg);
+}
+
 /*
  * Perform a checkpoint --- either during shutdown, or on-the-fly
  *
@@ -8905,6 +8930,9 @@ CreateCheckPoint(int flags)
 	if (log_checkpoints)
 		LogCheckpointStart(flags, false);
 
+	/* Update the process title */
+	set_ps_display_for_checkpoint(flags, false);
+
 	TRACE_POSTGRESQL_CHECKPOINT_START(flags);
 
 	/*
@@ -9120,6 +9148,9 @@ CreateCheckPoint(int flags)
 	/* Real work is done, but log and update stats before releasing lock. */
 	LogCheckpointEnd(false);
 
+	/* Reset the process title */
+	set_ps_display("");
+
 	TRACE_POSTGRESQL_CHECKPOINT_DONE(CheckpointStats.ckpt_bufs_written,
 									 NBuffers,
 									 CheckpointStats.ckpt_segs_added,
@@ -9374,6 +9405,9 @@ CreateRestartPoint(int flags)
 	if (log_checkpoints)
 		LogCheckpointStart(flags, true);
 
+	/* Update the process title */
+	set_ps_display_for_checkpoint(flags, true);
+
 	CheckPointGuts(lastCheckPoint.redo, flags);
 
 	/*
@@ -9492,6 +9526,9 @@ CreateRestartPoint(int flags)
 	/* Real work is done, but log and update before releasing lock. */
 	LogCheckpointEnd(true);
 
+	/* Reset the process title */
+	set_ps_display("");
+
 	xtime = GetLatestXTime();
 	ereport((log_checkpoints ? LOG : DEBUG2),
 			(errmsg("recovery restart point at %X/%X",
-- 
2.16.6