Count buffers dirtied due to hints in pgBufferUsage.shared_blks_dirtied.

robertmhaas · robertmhaas · commit ac2063ade566 · 2014-03-31T13:26:33.000-04:00
Previously, such buffers weren't counted, with the possible result that
EXPLAIN (BUFFERS) and pg_stat_statements would understate the true
number of blocks dirtied by an SQL statement.

Back-patch to 9.2, where this counter was introduced.

Amit Kapila
diff --git a/src/backend/storage/buffer/bufmgr.c b/src/backend/storage/buffer/bufmgr.c
@@ -2708,6 +2708,7 @@ MarkBufferDirtyHint(Buffer buffer, bool buffer_std)
 		if (dirtied)
 		{
 			VacuumPageDirty++;
+			pgBufferUsage.shared_blks_dirtied++;
 			if (VacuumCostActive)
 				VacuumCostBalance += VacuumCostPageDirty;
 		}

Original file line number	Diff line number	Diff line change
`@@ -2708,6 +2708,7 @@ MarkBufferDirtyHint(Buffer buffer, bool buffer_std)`
`2708`	`2708`	`if (dirtied)`
`2709`	`2709`	`{`
`2710`	`2710`	`VacuumPageDirty++;`
	`2711`	`+ pgBufferUsage.shared_blks_dirtied++;`
`2711`	`2712`	`if (VacuumCostActive)`
`2712`	`2713`	`VacuumCostBalance += VacuumCostPageDirty;`
`2713`	`2714`	`}`