From: Heikki Linnakangas <heikki.linnakangas@iki.fi>
Date: Thu, 25 Jan 2024 23:04:58 +0000 (+0200)
Subject: Update comment, generation mem contexts have a "keeper" block
X-Git-Tag: REL_17_BETA1~1008
X-Git-Url: http://git.postgresql.org/gitweb/?a=commitdiff_plain;h=376c216138c75e161d39767650ea30536f23b482;p=postgresql.git

Update comment, generation mem contexts have a "keeper" block

The keeper block was introduced in commit 1b0d9aa4f7, but it forgot
to update this comment.
---

diff --git a/src/backend/utils/mmgr/generation.c b/src/backend/utils/mmgr/generation.c
index 65fd00d0137..f9016a7ed72 100644
--- a/src/backend/utils/mmgr/generation.c
+++ b/src/backend/utils/mmgr/generation.c
@@ -271,8 +271,10 @@ GenerationContextCreate(MemoryContext parent,
  * GenerationReset
  *		Frees all memory which is allocated in the given set.
  *
- * The code simply frees all the blocks in the context - we don't keep any
- * keeper blocks or anything like that.
+ * The initial "keeper" block (which shares a malloc chunk with the context
+ * header) is not given back to the operating system though.  In this way, we
+ * don't thrash malloc() when a context is repeatedly reset after small
+ * allocations.
  */
 void
 GenerationReset(MemoryContext context)