diff options
Diffstat (limited to 'src/backend/postmaster/bgwriter.c')
| -rw-r--r-- | src/backend/postmaster/bgwriter.c | 50 |
1 files changed, 33 insertions, 17 deletions
diff --git a/src/backend/postmaster/bgwriter.c b/src/backend/postmaster/bgwriter.c index 0cd694ef529..d826a6190de 100644 --- a/src/backend/postmaster/bgwriter.c +++ b/src/backend/postmaster/bgwriter.c @@ -37,7 +37,7 @@ * * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/postmaster/bgwriter.c,v 1.16 2005/05/28 17:21:32 tgl Exp $ + * $PostgreSQL: pgsql/src/backend/postmaster/bgwriter.c,v 1.17 2005/06/30 00:00:51 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -86,8 +86,14 @@ * 6. If ckpt_failed is different from the originally saved value, * assume request failed; otherwise it was definitely successful. * + * An additional field is ckpt_time_warn; this is also sig_atomic_t for + * simplicity, but is only used as a boolean. If a backend is requesting + * a checkpoint for which a checkpoints-too-close-together warning is + * reasonable, it should set this field TRUE just before sending the signal. + * * The requests array holds fsync requests sent by backends and not yet - * absorbed by the bgwriter. + * absorbed by the bgwriter. Unlike the checkpoint fields, the requests + * fields are protected by BgWriterCommLock. *---------- */ typedef struct @@ -105,6 +111,8 @@ typedef struct sig_atomic_t ckpt_done; /* advances when checkpoint done */ sig_atomic_t ckpt_failed; /* advances when checkpoint fails */ + sig_atomic_t ckpt_time_warn; /* warn if too soon since last ckpt? */ + int num_requests; /* current # of requests */ int max_requests; /* allocated array size */ BgWriterRequest requests[1]; /* VARIABLE LENGTH ARRAY */ @@ -319,20 +327,20 @@ BackgroundWriterMain(void) */ if (do_checkpoint) { - if (CheckPointWarning != 0) - { - /* - * Ideally we should only warn if this checkpoint was - * requested due to running out of segment files, and not - * if it was manually requested. However we can't tell - * the difference with the current signalling mechanism. - */ - if (elapsed_secs < CheckPointWarning) - ereport(LOG, - (errmsg("checkpoints are occurring too frequently (%d seconds apart)", - elapsed_secs), - errhint("Consider increasing the configuration parameter \"checkpoint_segments\"."))); - } + /* + * We will warn if (a) too soon since last checkpoint (whatever + * caused it) and (b) somebody has set the ckpt_time_warn flag + * since the last checkpoint start. Note in particular that + * this implementation will not generate warnings caused by + * CheckPointTimeout < CheckPointWarning. + */ + if (BgWriterShmem->ckpt_time_warn && + elapsed_secs < CheckPointWarning) + ereport(LOG, + (errmsg("checkpoints are occurring too frequently (%d seconds apart)", + elapsed_secs), + errhint("Consider increasing the configuration parameter \"checkpoint_segments\"."))); + BgWriterShmem->ckpt_time_warn = false; /* * Indicate checkpoint start to any waiting backends. @@ -497,9 +505,13 @@ BgWriterShmemInit(void) * If waitforit is true, wait until the checkpoint is completed * before returning; otherwise, just signal the request and return * immediately. + * + * If warnontime is true, and it's "too soon" since the last checkpoint, + * the bgwriter will log a warning. This should be true only for checkpoints + * caused due to xlog filling, else the warning will be misleading. */ void -RequestCheckpoint(bool waitforit) +RequestCheckpoint(bool waitforit, bool warnontime) { /* use volatile pointer to prevent code rearrangement */ volatile BgWriterShmemStruct *bgs = BgWriterShmem; @@ -523,6 +535,10 @@ RequestCheckpoint(bool waitforit) return; } + /* Set warning request flag if appropriate */ + if (warnontime) + bgs->ckpt_time_warn = true; + /* * Send signal to request checkpoint. When waitforit is false, we * consider failure to send the signal to be nonfatal. |