0001-injection_points-Tweak-variable-numbered-stats-to-wo.patch

From d0aae1f873ec4f0cde91d851d131767e7ca66171 Mon Sep 17 00:00:00 2001
From: Michael Paquier <michael@paquier.xyz>
Date: Fri, 27 Dec 2024 09:16:02 +0900
Subject: [PATCH] injection_points: Tweak variable-numbered stats to work with
 pending data

As coded, the module was not using pending entries to store its data
locally before a flush to the central dshash is done with a timed
pgstat_report_stat() call.  Hence, the flush callback was defined, but
finished by being not used.  As a template, this is more efficient than
the original logic of updating directly the shared memory entries as
this reduces the interactions that need to be done with the pgstats
hash table in shared memory.

injection_stats_flush_cb() was also missing a pgstat_unlock_entry(), so
add one, while on it.
---
 .../modules/injection_points/injection_stats.c    | 15 ++++++++-------
 1 file changed, 8 insertions(+), 7 deletions(-)

diff --git a/src/test/modules/injection_points/injection_stats.c b/src/test/modules/injection_points/injection_stats.c
index e16b9db284..21d5c10f39 100644
--- a/src/test/modules/injection_points/injection_stats.c
+++ b/src/test/modules/injection_points/injection_stats.c
@@ -80,6 +80,9 @@ injection_stats_flush_cb(PgStat_EntryRef *entry_ref, bool nowait)
 		return false;
 
 	shfuncent->stats.numcalls += localent->numcalls;
+
+	pgstat_unlock_entry(entry_ref);
+
 	return true;
 }
 
@@ -127,13 +130,13 @@ pgstat_create_inj(const char *name)
 	if (!inj_stats_loaded || !inj_stats_enabled)
 		return;
 
-	entry_ref = pgstat_get_entry_ref_locked(PGSTAT_KIND_INJECTION, InvalidOid,
-											PGSTAT_INJ_IDX(name), false);
+	entry_ref = pgstat_prep_pending_entry(PGSTAT_KIND_INJECTION, InvalidOid,
+										  PGSTAT_INJ_IDX(name), NULL);
+
 	shstatent = (PgStatShared_InjectionPoint *) entry_ref->shared_stats;
 
 	/* initialize shared memory data */
 	memset(&shstatent->stats, 0, sizeof(shstatent->stats));
-	pgstat_unlock_entry(entry_ref);
 }
 
 /*
@@ -168,16 +171,14 @@ pgstat_report_inj(const char *name)
 	if (!inj_stats_loaded || !inj_stats_enabled)
 		return;
 
-	entry_ref = pgstat_get_entry_ref_locked(PGSTAT_KIND_INJECTION, InvalidOid,
-											PGSTAT_INJ_IDX(name), false);
+	entry_ref = pgstat_prep_pending_entry(PGSTAT_KIND_INJECTION, InvalidOid,
+										  PGSTAT_INJ_IDX(name), NULL);
 
 	shstatent = (PgStatShared_InjectionPoint *) entry_ref->shared_stats;
 	statent = &shstatent->stats;
 
 	/* Update the injection point statistics */
 	statent->numcalls++;
-
-	pgstat_unlock_entry(entry_ref);
 }
 
 /*
-- 
2.45.2