[Suspend2][ 04/32] [Suspend2] Check the io stats.

[Nigel Cunningham <nigel@suspend2.net>]

Perform sanity checking at the conclusion of performing some I/O. By the
time this is called, there should be no outstanding I/O, and the io_info
structure lists should all be empty. We check these conditions, and display
the vital statistics if the appropriate debugging level is enabled.

Signed-off-by: Nigel Cunningham <nigel@suspend2.net>

 kernel/power/suspend_block_io.c |   35 +++++++++++++++++++++++++++++++++++
 1 files changed, 35 insertions(+), 0 deletions(-)

diff --git a/kernel/power/suspend_block_io.c b/kernel/power/suspend_block_io.c
index 51e02ef..09682c4 100644
--- a/kernel/power/suspend_block_io.c
+++ b/kernel/power/suspend_block_io.c
@@ -144,3 +144,38 @@ static void suspend_reset_io_stats(void)
 		nr_schedule_calls[i] = 0;
 }
 
+/*
+ * suspend_check_io_stats
+ *
+ * Description:	Check that our statistics look right and print
+ * 		any debugging info wanted.
+ */
+static void suspend_check_io_stats(void)
+{
+	int i;
+
+	BUG_ON(atomic_read(&outstanding_io));
+	BUG_ON(infopages);
+	BUG_ON(!list_empty(&ioinfo_submit_batch));
+	BUG_ON(!list_empty(&ioinfo_busy));
+	BUG_ON(!list_empty(&ioinfo_ready_for_cleanup));
+	BUG_ON(!list_empty(&ioinfo_free));
+	BUG_ON(atomic_read(&buffer_allocs) != atomic_read(&buffer_frees));
+
+	suspend_message(SUSPEND_WRITER, SUSPEND_LOW, 0,
+			"Maximum outstanding_io was %d.\n",
+			max_outstanding_io);
+	suspend_message(SUSPEND_WRITER, SUSPEND_LOW, 0,
+			"Max info pages was %d.\n",
+			maxinfopages);
+	if (atomic_read(&buffer_allocs) != atomic_read(&buffer_frees))
+		suspend_message(SUSPEND_WRITER, SUSPEND_MEDIUM, 0,
+			"Buffer allocs (%d) != buffer frees (%d)",
+				atomic_read(&buffer_allocs),
+				atomic_read(&buffer_frees));
+	for(i = 0; i < 8; i++)
+		suspend_message(SUSPEND_WRITER, SUSPEND_MEDIUM, 0,
+			"Nr schedule calls %s: %lu.\n", sch_caller[i],
+			nr_schedule_calls[i]);
+}
+

--
Nigel Cunningham		nigel at suspend2 dot net