From 4eba7bbb739f5e7b95c4909d1cee2a437d8c6eb3 Mon Sep 17 00:00:00 2001 From: test Date: Sun, 3 May 2026 00:40:17 +0200 Subject: [PATCH 1/2] add fast parameter to enable/disable checksums XXX Should this default to true or false? Most production systems would probably want 'false' to reduce impact, but PG19 does fast checkpoints by default. --- doc/src/sgml/func/func-admin.sgml | 14 ++++++++++-- src/backend/access/transam/xlog.c | 23 ++++++++++++++------ src/backend/postmaster/datachecksum_state.c | 24 +++++++++++++++------ src/include/access/xlog.h | 4 ++-- src/include/catalog/pg_proc.dat | 11 +++++----- src/include/postmaster/datachecksum_state.h | 3 ++- 6 files changed, 56 insertions(+), 23 deletions(-) diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml index 24ecb46542e..06360ea1b95 100644 --- a/doc/src/sgml/func/func-admin.sgml +++ b/doc/src/sgml/func/func-admin.sgml @@ -3158,7 +3158,7 @@ SELECT convert_from(pg_read_binary_file('file_in_utf8.txt'), 'UTF8'); pg_enable_data_checksums - pg_enable_data_checksums ( cost_delay int, cost_limit int ) + pg_enable_data_checksums ( cost_delay int, cost_limit int, fast bool ) void @@ -3175,6 +3175,11 @@ SELECT convert_from(pg_read_binary_file('file_in_utf8.txt'), 'UTF8'); specified, the process is throttled using the same principles as Cost-based Vacuum Delay. + + If fast is specified as true + then a fast checkpoint will be issued when data checksums have been + enabled, which may cause a spike in I/O. + @@ -3183,7 +3188,7 @@ SELECT convert_from(pg_read_binary_file('file_in_utf8.txt'), 'UTF8'); pg_disable_data_checksums - pg_disable_data_checksums () + pg_disable_data_checksums ( fast bool ) void @@ -3193,6 +3198,11 @@ SELECT convert_from(pg_read_binary_file('file_in_utf8.txt'), 'UTF8'); stopped validating data checksums, the data checksum state will be set to off. + + If fast is specified as true + then a fast checkpoint will be issued when data checksums have been + enabled, which may cause a spike in I/O. + diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 18d5dee06e0..6b8b48fa4ce 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -4803,9 +4803,10 @@ SetDataChecksumsOnInProgress(void) * state transition. */ void -SetDataChecksumsOn(void) +SetDataChecksumsOn(bool fast) { uint64 barrier; + int flags; SpinLockAcquire(&XLogCtl->info_lck); @@ -4820,7 +4821,7 @@ SetDataChecksumsOn(void) SpinLockRelease(&XLogCtl->info_lck); elog(WARNING, "cannot set data checksums to \"on\", current state is not \"inprogress-on\", disabling"); - SetDataChecksumsOff(); + SetDataChecksumsOff(fast); return; } @@ -4850,7 +4851,11 @@ SetDataChecksumsOn(void) MyProc->delayChkptFlags &= ~DELAY_CHKPT_START; END_CRIT_SECTION(); - RequestCheckpoint(CHECKPOINT_FORCE | CHECKPOINT_WAIT | CHECKPOINT_FAST); + flags = CHECKPOINT_FORCE | CHECKPOINT_WAIT; + if (fast) + flags |= CHECKPOINT_FAST; + + RequestCheckpoint(flags); WaitForProcSignalBarrier(barrier); } @@ -4868,9 +4873,15 @@ SetDataChecksumsOn(void) * state transition. */ void -SetDataChecksumsOff(void) +SetDataChecksumsOff(bool fast) { uint64 barrier; + int flags; + + /* determine flags for the checkpoint(s) */ + flags = CHECKPOINT_FORCE | CHECKPOINT_WAIT; + if (fast) + flags |= CHECKPOINT_FAST; SpinLockAcquire(&XLogCtl->info_lck); @@ -4912,7 +4923,7 @@ SetDataChecksumsOff(void) MyProc->delayChkptFlags &= ~DELAY_CHKPT_START; END_CRIT_SECTION(); - RequestCheckpoint(CHECKPOINT_FORCE | CHECKPOINT_WAIT | CHECKPOINT_FAST); + RequestCheckpoint(flags); WaitForProcSignalBarrier(barrier); /* @@ -4950,7 +4961,7 @@ SetDataChecksumsOff(void) MyProc->delayChkptFlags &= ~DELAY_CHKPT_START; END_CRIT_SECTION(); - RequestCheckpoint(CHECKPOINT_FORCE | CHECKPOINT_WAIT | CHECKPOINT_FAST); + RequestCheckpoint(flags); WaitForProcSignalBarrier(barrier); } diff --git a/src/backend/postmaster/datachecksum_state.c b/src/backend/postmaster/datachecksum_state.c index d0d6acdd6a2..286096217d9 100644 --- a/src/backend/postmaster/datachecksum_state.c +++ b/src/backend/postmaster/datachecksum_state.c @@ -291,6 +291,7 @@ typedef struct DataChecksumsStateStruct DataChecksumsWorkerOperation launch_operation; int launch_cost_delay; int launch_cost_limit; + bool launch_fast_checkpoint; /* * Is a launcher process currently running? This is set by the main @@ -318,6 +319,7 @@ typedef struct DataChecksumsStateStruct DataChecksumsWorkerOperation operation; int cost_delay; int cost_limit; + bool fast_checkpoint; /* * Signaling between the launcher and the worker process. @@ -509,6 +511,8 @@ AbsorbDataChecksumsBarrier(ProcSignalBarrierType barrier) Datum disable_data_checksums(PG_FUNCTION_ARGS) { + bool fast = PG_GETARG_BOOL(0); + PreventCommandDuringRecovery("pg_disable_data_checksums()"); if (!superuser()) @@ -516,7 +520,7 @@ disable_data_checksums(PG_FUNCTION_ARGS) errcode(ERRCODE_INSUFFICIENT_PRIVILEGE), errmsg("must be superuser to change data checksum state")); - StartDataChecksumsWorkerLauncher(DISABLE_DATACHECKSUMS, 0, 0); + StartDataChecksumsWorkerLauncher(DISABLE_DATACHECKSUMS, 0, 0, fast); PG_RETURN_VOID(); } @@ -530,6 +534,7 @@ enable_data_checksums(PG_FUNCTION_ARGS) { int cost_delay = PG_GETARG_INT32(0); int cost_limit = PG_GETARG_INT32(1); + bool fast = PG_GETARG_BOOL(2); PreventCommandDuringRecovery("pg_enable_data_checksums()"); @@ -548,7 +553,7 @@ enable_data_checksums(PG_FUNCTION_ARGS) errcode(ERRCODE_INVALID_PARAMETER_VALUE), errmsg("cost limit must be greater than zero")); - StartDataChecksumsWorkerLauncher(ENABLE_DATACHECKSUMS, cost_delay, cost_limit); + StartDataChecksumsWorkerLauncher(ENABLE_DATACHECKSUMS, cost_delay, cost_limit, fast); PG_RETURN_VOID(); } @@ -568,7 +573,8 @@ enable_data_checksums(PG_FUNCTION_ARGS) void StartDataChecksumsWorkerLauncher(DataChecksumsWorkerOperation op, int cost_delay, - int cost_limit) + int cost_limit, + bool fast) { BackgroundWorker bgw; BackgroundWorkerHandle *bgw_handle; @@ -588,6 +594,7 @@ StartDataChecksumsWorkerLauncher(DataChecksumsWorkerOperation op, DataChecksumState->launch_operation = op; DataChecksumState->launch_cost_delay = cost_delay; DataChecksumState->launch_cost_limit = cost_limit; + DataChecksumState->launch_fast_checkpoint = fast; /* Is the launcher already running? If so, what is it doing? */ running = DataChecksumState->launcher_running; @@ -938,7 +945,7 @@ launcher_exit(int code, Datum arg) * the state to off since processing cannot be resumed. */ if (DataChecksumsInProgressOn()) - SetDataChecksumsOff(); + SetDataChecksumsOff(DataChecksumState->fast_checkpoint); LWLockAcquire(DataChecksumsWorkerLock, LW_EXCLUSIVE); launcher_running = false; @@ -1081,6 +1088,7 @@ DataChecksumsWorkerLauncherMain(Datum arg) DataChecksumState->operation = operation; DataChecksumState->cost_delay = DataChecksumState->launch_cost_delay; DataChecksumState->cost_limit = DataChecksumState->launch_cost_limit; + DataChecksumState->fast_checkpoint = DataChecksumState->launch_fast_checkpoint; LWLockRelease(DataChecksumsWorkerLock); /* @@ -1139,7 +1147,7 @@ again: * Data checksums have been set on all pages, set the state to on in * order to instruct backends to validate checksums on reading. */ - SetDataChecksumsOn(); + SetDataChecksumsOn(DataChecksumState->fast_checkpoint); ereport(LOG, errmsg("data checksums are now enabled")); @@ -1151,7 +1159,7 @@ again: pgstat_progress_update_param(PROGRESS_DATACHECKSUMS_PHASE, PROGRESS_DATACHECKSUMS_PHASE_DISABLING); - SetDataChecksumsOff(); + SetDataChecksumsOff(DataChecksumState->fast_checkpoint); ereport(LOG, errmsg("data checksums are now disabled")); } @@ -1179,6 +1187,7 @@ done: operation = DataChecksumState->launch_operation; DataChecksumState->cost_delay = DataChecksumState->launch_cost_delay; DataChecksumState->cost_limit = DataChecksumState->launch_cost_limit; + DataChecksumState->fast_checkpoint = DataChecksumState->launch_fast_checkpoint; LWLockRelease(DataChecksumsWorkerLock); goto again; } @@ -1268,7 +1277,7 @@ ProcessAllDatabases(void) * Disable checksums on cluster, because we failed one of the * databases and this is an all or nothing process. */ - SetDataChecksumsOff(); + SetDataChecksumsOff(DataChecksumState->fast_checkpoint); ereport(ERROR, errcode(ERRCODE_INSUFFICIENT_RESOURCES), errmsg("data checksums failed to get enabled in all databases, aborting"), @@ -1606,6 +1615,7 @@ DataChecksumsWorkerMain(Datum arg) DataChecksumState->cost_delay = DataChecksumState->launch_cost_delay; DataChecksumState->cost_limit = DataChecksumState->launch_cost_limit; + DataChecksumState->fast_checkpoint = DataChecksumState->launch_fast_checkpoint; } else costs_updated = false; diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index 4dd98624204..8a9e8961a6a 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -253,8 +253,8 @@ extern bool DataChecksumsOn(void); extern bool DataChecksumsOff(void); extern bool DataChecksumsInProgressOn(void); extern void SetDataChecksumsOnInProgress(void); -extern void SetDataChecksumsOn(void); -extern void SetDataChecksumsOff(void); +extern void SetDataChecksumsOn(bool fast); +extern void SetDataChecksumsOff(bool fast); extern const char *show_data_checksums(void); extern const char *get_checksum_state_string(uint32 state); extern void InitLocalDataChecksumState(void); diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat index fa9ae79082b..fed5fba4c0c 100644 --- a/src/include/catalog/pg_proc.dat +++ b/src/include/catalog/pg_proc.dat @@ -12457,14 +12457,15 @@ { oid => '9258', descr => 'disable data checksums', proname => 'pg_disable_data_checksums', provolatile => 'v', prorettype => 'void', - proparallel => 'r', prosrc => 'disable_data_checksums', proargtypes => '', - proacl => '{POSTGRES=X}'}, + proparallel => 'r', prosrc => 'disable_data_checksums', proargtypes => 'bool', + proallargtypes => '{bool}', proargmodes => '{i}', proargnames => '{fast}', + proargdefaults => '{true}', proacl => '{POSTGRES=X}'}, { oid => '9257', descr => 'enable data checksums', proname => 'pg_enable_data_checksums', provolatile => 'v', prorettype => 'void', - proparallel => 'r', proargtypes => 'int4 int4', proallargtypes => '{int4,int4}', - proargmodes => '{i,i}', proargnames => '{cost_delay,cost_limit}', - proargdefaults => '{0,100}', prosrc => 'enable_data_checksums', + proparallel => 'r', proargtypes => 'int4 int4 bool', proallargtypes => '{int4,int4,bool}', + proargmodes => '{i,i,i}', proargnames => '{cost_delay,cost_limit,fast}', + proargdefaults => '{0,100,true}', prosrc => 'enable_data_checksums', proacl => '{POSTGRES=X}'}, # collation management functions diff --git a/src/include/postmaster/datachecksum_state.h b/src/include/postmaster/datachecksum_state.h index 2a1ae10d55d..6bd975c0670 100644 --- a/src/include/postmaster/datachecksum_state.h +++ b/src/include/postmaster/datachecksum_state.h @@ -45,7 +45,8 @@ void EmitAndWaitDataChecksumsBarrier(uint32 state); /* Start the background processes for enabling or disabling checksums */ void StartDataChecksumsWorkerLauncher(DataChecksumsWorkerOperation op, int cost_delay, - int cost_limit); + int cost_limit, + bool fast); /* Background worker entrypoints */ void DataChecksumsWorkerLauncherMain(Datum arg); -- 2.54.0