v4-0006-wait_event_arg-expose-buffer-for-Buffer-type-wait.patch

From 43c9a437a61970216f97ed6161c04da48a1a505f Mon Sep 17 00:00:00 2001
From: Jakub Wartak <jakub.wartak@enterprisedb.com>
Date: Wed, 11 Feb 2026 15:01:17 +0100
Subject: [PATCH v4 6/6] wait_event_arg: expose buffer# for Buffer-type wait
 events

---
 src/backend/storage/buffer/bufmgr.c             | 11 ++++++++---
 src/backend/utils/activity/wait_event_names.txt | 11 ++++++-----
 2 files changed, 14 insertions(+), 8 deletions(-)

diff --git a/src/backend/storage/buffer/bufmgr.c b/src/backend/storage/buffer/bufmgr.c
index 92c924bc64e..52f54b191c4 100644
--- a/src/backend/storage/buffer/bufmgr.c
+++ b/src/backend/storage/buffer/bufmgr.c
@@ -5831,7 +5831,9 @@ BufferLockAcquire(Buffer buffer, BufferDesc *buf_hdr, BufferLockMode mode)
 				pg_unreachable();
 
 		}
-		pgstat_report_wait_start(wait_event);
+		/* Local buffers can get negative */
+		pgstat_report_wait_start(wait_event |
+						   (uint32) ((buffer>=0) ? buffer : UINT32_MAX));
 
 		/*
 		 * Wait until awakened.
@@ -6643,7 +6645,9 @@ LockBufferForCleanup(Buffer buffer)
 			SetStartupBufferPinWaitBufId(-1);
 		}
 		else
-			ProcWaitForSignal(WAIT_EVENT_BUFFER_CLEANUP);
+			/* Local buffers can get negative */
+			ProcWaitForSignal(WAIT_EVENT_BUFFER_CLEANUP |
+					 (uint32) ((buffer>=0) ? buffer : UINT32_MAX));
 
 		/*
 		 * Remove flag marking us as waiter. Normally this will not be set
@@ -6858,7 +6862,8 @@ WaitIO(BufferDesc *buf)
 		}
 
 		/* wait on BufferDesc->cv, e.g. for concurrent synchronous IO */
-		ConditionVariableSleep(cv, WAIT_EVENT_BUFFER_IO);
+		ConditionVariableSleep(cv, WAIT_EVENT_BUFFER_IO |
+					 (uint32) ((buf->buf_id>=0) ? buf->buf_id : UINT32_MAX));
 	}
 	ConditionVariableCancelSleep();
 }
diff --git a/src/backend/utils/activity/wait_event_names.txt b/src/backend/utils/activity/wait_event_names.txt
index b86ebd3b2c2..b1442680882 100644
--- a/src/backend/utils/activity/wait_event_names.txt
+++ b/src/backend/utils/activity/wait_event_names.txt
@@ -114,7 +114,7 @@ BACKUP_WAIT_WAL_ARCHIVE	"Waiting for WAL files required for a backup to be succe
 BGWORKER_SHUTDOWN	"Waiting for background worker to shut down."
 BGWORKER_STARTUP	"Waiting for background worker to start up."
 BTREE_PAGE	"Waiting for the page number needed to continue a parallel B-tree scan to become available."
-BUFFER_IO	"Waiting for buffer I/O to complete."
+BUFFER_IO	"Waiting for buffer I/O to complete."	"Buffer# or UINT32_MAX for local(temporary) buffers."
 CHECKPOINT_DELAY_COMPLETE	"Waiting for a backend that blocks a checkpoint from completing."
 CHECKPOINT_DELAY_START	"Waiting for a backend that blocks a checkpoint from starting."
 CHECKPOINT_DONE	"Waiting for a checkpoint to complete."
@@ -288,10 +288,11 @@ ABI_compatibility:
 
 Section: ClassName - WaitEventBuffer
 
-BUFFER_CLEANUP	"Waiting to acquire an exclusive pin on a buffer. Buffer pin waits can be protracted if another process holds an open cursor that last read data from the buffer in question."
-BUFFER_SHARED	"Waiting to acquire a shared lock on a buffer."
-BUFFER_SHARE_EXCLUSIVE	"Waiting to acquire a share exclusive lock on a buffer."
-BUFFER_EXCLUSIVE	"Waiting to acquire a exclusive lock on a buffer."
+BUFFER_CLEANUP	"Waiting to acquire an exclusive pin on a buffer. Buffer pin waits can be protracted if another process holds an open cursor that last read data from the buffer in question."	"Buffer# or UINT32_MAX for local(temporary) buffers."
+BUFFER_SHARED	"Waiting to acquire a shared lock on a buffer."	"Buffer# or UINT32_MAX for local(temporary) buffers."
+BUFFER_SHARE_EXCLUSIVE	"Waiting to acquire a share exclusive lock on a buffer."	"Buffer# or UINT32_MAX for local(temporary) buffers."
+BUFFER_EXCLUSIVE	"Waiting to acquire a exclusive lock on a buffer."	"Buffer# or UINT32_MAX for local(temporary) buffers."
+
 
 ABI_compatibility:
 
-- 
2.43.0