>From bccfdcce4fff4e89ba6dd6779a449ec875f6b03f Mon Sep 17 00:00:00 2001 From: Andres Freund Date: Wed, 27 Nov 2013 17:24:13 +0100 Subject: [PATCH 3/3] Debugging tool for burning mxact ids. Do not apply for real. --- contrib/pageinspect/heapfuncs.c | 34 ++++++++++++++++++++++++++++++++ contrib/pageinspect/pageinspect--1.1.sql | 5 +++++ src/backend/access/transam/multixact.c | 16 ++++++++------- src/backend/utils/misc/guc.c | 2 +- src/include/access/multixact.h | 1 + 5 files changed, 50 insertions(+), 8 deletions(-) diff --git a/contrib/pageinspect/heapfuncs.c b/contrib/pageinspect/heapfuncs.c index 6d8f6f1..c021739 100644 --- a/contrib/pageinspect/heapfuncs.c +++ b/contrib/pageinspect/heapfuncs.c @@ -29,6 +29,8 @@ #include "funcapi.h" #include "utils/builtins.h" #include "miscadmin.h" +#include "access/multixact.h" +#include "access/transam.h" Datum heap_page_items(PG_FUNCTION_ARGS); @@ -224,3 +226,35 @@ heap_page_items(PG_FUNCTION_ARGS) else SRF_RETURN_DONE(fctx); } + +extern Datum +pg_burn_multixact(PG_FUNCTION_ARGS); +PG_FUNCTION_INFO_V1(pg_burn_multixact); + +Datum +pg_burn_multixact(PG_FUNCTION_ARGS) +{ + int rep = PG_GETARG_INT32(0); + MultiXactMember members[2]; + MultiXactId ret; + TransactionId id = FirstNormalTransactionId; + int i; + + if (rep < 1) + elog(ERROR, "need to burn, burn, burn"); + + for (i = 0; i < 2; i++) + { + members[i].xid = id++; + members[i].status = MultiXactStatusForShare; + } + + MultiXactIdSetOldestMember(); + + for (i = 0; i < rep; i++) + { + ret = CreateMultiXactId(2, members, true); + } + + PG_RETURN_INT64((int64)ret); +} diff --git a/contrib/pageinspect/pageinspect--1.1.sql b/contrib/pageinspect/pageinspect--1.1.sql index 22a47d5..14f87fb 100644 --- a/contrib/pageinspect/pageinspect--1.1.sql +++ b/contrib/pageinspect/pageinspect--1.1.sql @@ -105,3 +105,8 @@ CREATE FUNCTION fsm_page_contents(IN page bytea) RETURNS text AS 'MODULE_PATHNAME', 'fsm_page_contents' LANGUAGE C STRICT; + +CREATE FUNCTION pg_burn_multixact(num int4) +RETURNS int4 +AS 'MODULE_PATHNAME', 'pg_burn_multixact' +LANGUAGE C STRICT; diff --git a/src/backend/access/transam/multixact.c b/src/backend/access/transam/multixact.c index 9e071b4..63fcd8c 100644 --- a/src/backend/access/transam/multixact.c +++ b/src/backend/access/transam/multixact.c @@ -286,7 +286,6 @@ static MemoryContext MXactContext = NULL; /* internal MultiXactId management */ static void MultiXactIdSetOldestVisible(void); -static MultiXactId CreateMultiXactId(int nmembers, MultiXactMember *members); static void RecordNewMultiXact(MultiXactId multi, MultiXactOffset offset, int nmembers, MultiXactMember *members); static MultiXactId GetNewMultiXactId(int nmembers, MultiXactOffset *offset); @@ -344,7 +343,7 @@ MultiXactIdCreate(TransactionId xid1, MultiXactStatus status1, members[1].xid = xid2; members[1].status = status2; - newMulti = CreateMultiXactId(2, members); + newMulti = CreateMultiXactId(2, members, false); debug_elog3(DEBUG2, "Create: %s", mxid_to_string(newMulti, 2, members)); @@ -407,7 +406,7 @@ MultiXactIdExpand(MultiXactId multi, TransactionId xid, MultiXactStatus status) */ member.xid = xid; member.status = status; - newMulti = CreateMultiXactId(1, &member); + newMulti = CreateMultiXactId(1, &member, false); debug_elog4(DEBUG2, "Expand: %u has no members, create singleton %u", multi, newMulti); @@ -456,7 +455,7 @@ MultiXactIdExpand(MultiXactId multi, TransactionId xid, MultiXactStatus status) newMembers[j].xid = xid; newMembers[j++].status = status; - newMulti = CreateMultiXactId(j, newMembers); + newMulti = CreateMultiXactId(j, newMembers, false); pfree(members); pfree(newMembers); @@ -669,8 +668,8 @@ ReadNextMultiXactId(void) * * NB: the passed members[] array will be sorted in-place. */ -static MultiXactId -CreateMultiXactId(int nmembers, MultiXactMember *members) +MultiXactId +CreateMultiXactId(int nmembers, MultiXactMember *members, bool nocache) { MultiXactId multi; MultiXactOffset offset; @@ -690,7 +689,10 @@ CreateMultiXactId(int nmembers, MultiXactMember *members) * corner cases where someone else added us to a MultiXact without our * knowledge, but it's not worth checking for.) */ - multi = mXactCacheGetBySet(nmembers, members); + if (nocache) + multi = InvalidMultiXactId; + else + multi = mXactCacheGetBySet(nmembers, members); if (MultiXactIdIsValid(multi)) { debug_elog2(DEBUG2, "Create: in cache!"); diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c index cbf3186..c139597 100644 --- a/src/backend/utils/misc/guc.c +++ b/src/backend/utils/misc/guc.c @@ -2332,7 +2332,7 @@ static struct config_int ConfigureNamesInt[] = }, &autovacuum_freeze_max_age, /* see pg_resetxlog if you change the upper-limit value */ - 200000000, 100000000, 2000000000, + 200000000, 50000000, 2000000000, NULL, NULL, NULL }, { diff --git a/src/include/access/multixact.h b/src/include/access/multixact.h index 348f84e..d7c7e45 100644 --- a/src/include/access/multixact.h +++ b/src/include/access/multixact.h @@ -79,6 +79,7 @@ typedef struct xl_multixact_create extern MultiXactId MultiXactIdCreate(TransactionId xid1, MultiXactStatus status1, TransactionId xid2, MultiXactStatus status2); +extern MultiXactId CreateMultiXactId(int nmembers, MultiXactMember *members, bool nocache); extern MultiXactId MultiXactIdExpand(MultiXactId multi, TransactionId xid, MultiXactStatus status); extern MultiXactId ReadNextMultiXactId(void); -- 1.8.5.rc2.dirty