Commit bd839171 authored by Julian Wiedmann's avatar Julian Wiedmann Committed by Vasily Gorbik
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s390/qdio: track time of last data IRQ for each device 



We currently track the time of the most recent QDIO Adapter Interrupt.
This is a system-wide timestamp (as such interrupts are not bound to
one specific qdio device).

If interrupt processing stalls on one device but is functional for a
different device, the timestamp continues to be updated and is of no
help for problem diagnosis.
So for debugging purposes also track the time of the last Data IRQ on
a per-device level. Collect this data in the legacy non-AI path as well.

Signed-off-by: default avatarJulian Wiedmann <jwi@linux.ibm.com>
Reviewed-by: default avatarBenjamin Block <bblock@linux.ibm.com>
Signed-off-by: default avatarVasily Gorbik <gor@linux.ibm.com>
parent 954d6235

drivers/s390/cio/qdio.h

+1 −0
Original line number Diff line number Diff line
@@ -252,6 +252,7 @@ struct qdio_irq { 
	struct ccw_device *cdev;

	struct list_head entry;		/* list of thinint devices */

	struct dentry *debugfs_dev;

	u64 last_data_irq_time;



	unsigned long int_parm;

	struct subchannel_id schid;

drivers/s390/cio/qdio_debug.c

+3 −2
Original line number Diff line number Diff line
@@ -105,8 +105,9 @@ static int qstat_show(struct seq_file *m, void *v) 
	if (!q)

		return 0;



	seq_printf(m, "Timestamp: %Lx  Last AI: %Lx\n",

		   q->timestamp, last_ai_time);

	seq_printf(m, "Timestamp: %llx\n", q->timestamp);

	seq_printf(m, "Last Data IRQ: %llx  Last AI: %llx\n",

		   q->irq_ptr->last_data_irq_time, last_ai_time);

	seq_printf(m, "nr_used: %d  ftc: %d\n",

		   atomic_read(&q->nr_buf_used), q->first_to_check);

	if (q->is_input_q) {

drivers/s390/cio/qdio_main.c

+1 −0
Original line number Diff line number Diff line
@@ -804,6 +804,7 @@ static void qdio_int_handler_pci(struct qdio_irq *irq_ptr) 
		return;



	qdio_deliver_irq(irq_ptr);

	irq_ptr->last_data_irq_time = S390_lowcore.int_clock;



	if (!pci_out_supported(irq_ptr) || !irq_ptr->scan_threshold)

		return;

drivers/s390/cio/qdio_thinint.c

+3 −1
Original line number Diff line number Diff line
@@ -97,10 +97,11 @@ static inline u32 clear_shared_ind(void) 
 */

static void tiqdio_thinint_handler(struct airq_struct *airq, bool floating)

{

	u64 irq_time = S390_lowcore.int_clock;

	u32 si_used = clear_shared_ind();

	struct qdio_irq *irq;



	last_ai_time = S390_lowcore.int_clock;

	last_ai_time = irq_time;

	inc_irq_stat(IRQIO_QAI);



	/* protect tiq_list entries, only changed in activate or shutdown */
@@ -119,6 +120,7 @@ static void tiqdio_thinint_handler(struct airq_struct *airq, bool floating) 
		}



		qdio_deliver_irq(irq);

		irq->last_data_irq_time = irq_time;



		QDIO_PERF_STAT_INC(irq, adapter_int);

	}