From 05b4293bd82035b22d673da90e64eae38beb4ceb Mon Sep 17 00:00:00 2001 From: Tom Lane Date: Sat, 14 May 2005 20:29:13 +0000 Subject: [PATCH] Minor speed hacks in AllocSetReset: avoid clearing the freelist headers when the blocks list is empty (there can surely be no freelist items if the context contains no memory), and use MemSetAligned not MemSet to clear the headers (we assume alignof(pointer) >= alignof(int32)). Per discussion with Atsushi Ogawa. He proposes some further hacking that I'm not yet sold on, but these two changes are unconditional wins since there is no case in which they make things slower. --- src/backend/utils/mmgr/aset.c | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-) diff --git a/src/backend/utils/mmgr/aset.c b/src/backend/utils/mmgr/aset.c index 386d4508b3..4f60b186c2 100644 --- a/src/backend/utils/mmgr/aset.c +++ b/src/backend/utils/mmgr/aset.c @@ -11,7 +11,7 @@ * Portions Copyright (c) 1994, Regents of the University of California * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/utils/mmgr/aset.c,v 1.59 2004/12/31 22:02:48 pgsql Exp $ + * $PostgreSQL: pgsql/src/backend/utils/mmgr/aset.c,v 1.60 2005/05/14 20:29:13 tgl Exp $ * * NOTE: * This is a new (Feb. 05, 1999) implementation of the allocation set @@ -395,12 +395,17 @@ AllocSetReset(MemoryContext context) AllocSetCheck(context); #endif + /* Nothing to do if context has never contained any data */ + if (block == NULL) + return; + /* Clear chunk freelists */ - MemSet(set->freelist, 0, sizeof(set->freelist)); + MemSetAligned(set->freelist, 0, sizeof(set->freelist)); + /* New blocks list is either empty or just the keeper block */ set->blocks = set->keeper; - while (block != NULL) + do { AllocBlock next = block->next; @@ -427,6 +432,7 @@ AllocSetReset(MemoryContext context) } block = next; } + while (block != NULL); } /* @@ -451,7 +457,7 @@ AllocSetDelete(MemoryContext context) #endif /* Make it look empty, just in case... */ - MemSet(set->freelist, 0, sizeof(set->freelist)); + MemSetAligned(set->freelist, 0, sizeof(set->freelist)); set->blocks = NULL; set->keeper = NULL; -- 2.40.0