From bd83917155c1e60a6634dfef708972076b068c6e Mon Sep 17 00:00:00 2001 From: Julian Wiedmann Date: Tue, 15 Sep 2020 10:04:39 +0300 Subject: [PATCH] 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: Julian Wiedmann Reviewed-by: Benjamin Block Signed-off-by: Vasily Gorbik --- drivers/s390/cio/qdio.h | 1 + drivers/s390/cio/qdio_debug.c | 5 +++-- drivers/s390/cio/qdio_main.c | 1 + drivers/s390/cio/qdio_thinint.c | 4 +++- 4 files changed, 8 insertions(+), 3 deletions(-) diff --git a/drivers/s390/cio/qdio.h b/drivers/s390/cio/qdio.h index 4a4e4de45bc9..da29c3729cd9 100644 --- a/drivers/s390/cio/qdio.h +++ b/drivers/s390/cio/qdio.h @@ -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; diff --git a/drivers/s390/cio/qdio_debug.c b/drivers/s390/cio/qdio_debug.c index 728abf7e9ccb..d091ae12c367 100644 --- a/drivers/s390/cio/qdio_debug.c +++ b/drivers/s390/cio/qdio_debug.c @@ -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) { diff --git a/drivers/s390/cio/qdio_main.c b/drivers/s390/cio/qdio_main.c index 3b1e8ed4ba14..c56b690f0a93 100644 --- a/drivers/s390/cio/qdio_main.c +++ b/drivers/s390/cio/qdio_main.c @@ -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; diff --git a/drivers/s390/cio/qdio_thinint.c b/drivers/s390/cio/qdio_thinint.c index e1b923633372..8e09bf3a2fcd 100644 --- a/drivers/s390/cio/qdio_thinint.c +++ b/drivers/s390/cio/qdio_thinint.c @@ -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); }