diff options
| -rw-r--r-- | src/backend/storage/buffer/bufmgr.c | 13 |
1 files changed, 12 insertions, 1 deletions
diff --git a/src/backend/storage/buffer/bufmgr.c b/src/backend/storage/buffer/bufmgr.c index 4c7cfb0b404..d07c997d47c 100644 --- a/src/backend/storage/buffer/bufmgr.c +++ b/src/backend/storage/buffer/bufmgr.c @@ -1474,7 +1474,18 @@ BgBufferSync(void) smoothing_samples; /* Scale the estimate by a GUC to allow more aggressive tuning. */ - upcoming_alloc_est = smoothed_alloc * bgwriter_lru_multiplier; + upcoming_alloc_est = (int) (smoothed_alloc * bgwriter_lru_multiplier); + + /* + * If recent_alloc remains at zero for many cycles, smoothed_alloc will + * eventually underflow to zero, and the underflows produce annoying + * kernel warnings on some platforms. Once upcoming_alloc_est has gone + * to zero, there's no point in tracking smaller and smaller values of + * smoothed_alloc, so just reset it to exactly zero to avoid this + * syndrome. It will pop back up as soon as recent_alloc increases. + */ + if (upcoming_alloc_est == 0) + smoothed_alloc = 0; /* * Even in cases where there's been little or no buffer allocation |