diff options
| -rw-r--r-- | src/backend/storage/buffer/bufmgr.c | 18 |
1 files changed, 15 insertions, 3 deletions
diff --git a/src/backend/storage/buffer/bufmgr.c b/src/backend/storage/buffer/bufmgr.c index 2ca2ab9753c..2109cbf8587 100644 --- a/src/backend/storage/buffer/bufmgr.c +++ b/src/backend/storage/buffer/bufmgr.c @@ -1595,9 +1595,21 @@ PinBuffer(BufferDesc *buf, BufferAccessStrategy strategy) /* increase refcount */ buf_state += BUF_REFCOUNT_ONE; - /* increase usagecount unless already max */ - if (BUF_STATE_GET_USAGECOUNT(buf_state) != BM_MAX_USAGE_COUNT) - buf_state += BUF_USAGECOUNT_ONE; + if (strategy == NULL) + { + /* Default case: increase usagecount unless already max. */ + if (BUF_STATE_GET_USAGECOUNT(buf_state) < BM_MAX_USAGE_COUNT) + buf_state += BUF_USAGECOUNT_ONE; + } + else + { + /* + * Ring buffers shouldn't evict others from pool. Thus we + * don't make usagecount more than 1. + */ + if (BUF_STATE_GET_USAGECOUNT(buf_state) == 0) + buf_state += BUF_USAGECOUNT_ONE; + } if (pg_atomic_compare_exchange_u32(&buf->state, &old_buf_state, buf_state)) |