v20251126-0009-mbind-procs.patch

From 6a7b5f0c48b861a78baafad699802752edfce669 Mon Sep 17 00:00:00 2001
From: Tomas Vondra <tomas@vondra.me>
Date: Wed, 26 Nov 2025 17:13:09 +0100
Subject: [PATCH v20251126 9/9] mbind: procs

---
 src/backend/storage/lmgr/proc.c | 17 ++++++++++++++---
 1 file changed, 14 insertions(+), 3 deletions(-)

diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c
index 0a0ce98b725..3d76a3a6429 100644
--- a/src/backend/storage/lmgr/proc.c
+++ b/src/backend/storage/lmgr/proc.c
@@ -206,11 +206,14 @@ FastPathLockShmemSize(void)
 	 * when not strictly needed (if it's already aligned). And we always
 	 * assume we'll add a whole page, even if the alignment needs only less
 	 * memory.
+	 *
+	 * XXX We need two extra pages. One for the non-NUMA part (aux processes),
+	 * and one to keep the size of the last chunk aligned too.
 	 */
 	if (((numa_flags & NUMA_PROCS) != 0) && numa_can_partition)
 	{
 		Assert(numa_nodes > 0);
-		size = add_size(size, mul_size((numa_nodes + 1), numa_page_size));
+		size = add_size(size, mul_size((numa_nodes + 2), numa_page_size));
 	}
 
 	return size;
@@ -324,6 +327,7 @@ InitProcGlobal(void)
 
 	/* Used for setup of per-backend fast-path slots. */
 	char	   *fpPtr,
+			   *fpPtrOrig,
 			   *fpEndPtr PG_USED_FOR_ASSERTS_ONLY;
 	Size		fpLockBitsSize,
 				fpRelIdSize;
@@ -507,7 +511,7 @@ InitProcGlobal(void)
 							requestSize,
 							&found);
 
-	MemSet(fpPtr, 0, requestSize);
+	fpPtrOrig = fpPtr;
 
 	/* For asserts checking we did not overflow. */
 	fpEndPtr = fpPtr + requestSize;
@@ -595,6 +599,9 @@ InitProcGlobal(void)
 		Assert(fpPtr <= fpEndPtr);
 	}
 
+	/* zero the memory only after locating the memory to NUMA nodes */
+	MemSet(fpPtrOrig, 0, requestSize);
+
 	for (i = 0; i < TotalProcs; i++)
 	{
 		PGPROC	   *proc = procs[i];
@@ -2521,7 +2528,10 @@ fastpath_partition_init(char *ptr, int num_procs, int allprocs_index, int node,
 	 * memory, to make sure it's not mapped to any node yet
 	 */
 	if (node != -1)
+	{
+		endptr = (char *) TYPEALIGN(numa_page_size, endptr);
 		pg_numa_move_to_node(ptr, endptr, node);
+	}
 
 	/*
 	 * Now point the PGPROC entries to the fast-path arrays, and also advance
@@ -2550,7 +2560,8 @@ fastpath_partition_init(char *ptr, int num_procs, int allprocs_index, int node,
 		allprocs_index++;
 	}
 
-	Assert(ptr == endptr);
+	Assert(ptr <= endptr);
+	Assert((node == -1) || (char *) TYPEALIGN(numa_page_size, ptr) == endptr);
 
 	return endptr;
 }
-- 
2.51.1