| Message ID | 20210209062437.6954-2-adrian.hunter@intel.com |
|---|---|
| State | New |
| Headers | show |
| Series | [V2,1/4] scsi: ufs: Add exception event tracepoint | expand |
> > Currently, exception event status can be read from wExceptionEventStatus > attribute (sysfs file attributes/exception_event_status under the UFS host > controller device directory). Polling that attribute to track UFS exception > events is impractical, so add a tracepoint to track exception events for > testing and debugging purposes. > > Note, by the time the exception event status is read, the exception event > may have cleared, so the value can be zero - see example below. > > Note also, only enabled exception events can be reported. A subsequent > patch adds the ability for users to enable selected exception events via > debugfs. > > Example with driver instrumented to enable all exception events: > > # echo 1 > > /sys/kernel/debug/tracing/events/ufs/ufshcd_exception_event/enable > > ... do some I/O ... > > # cat /sys/kernel/debug/tracing/trace > # tracer: nop > # > # entries-in-buffer/entries-written: 3/3 #P:5 > # > # _-----=> irqs-off > # / _----=> need-resched > # | / _---=> hardirq/softirq > # || / _--=> preempt-depth > # ||| / delay > # TASK-PID CPU# |||| TIMESTAMP FUNCTION > # | | | |||| | | > kworker/2:2-173 [002] .... 731.486419: ufshcd_exception_event: > 0000:00:12.5: status 0x0 > kworker/2:2-173 [002] .... 732.608918: ufshcd_exception_event: > 0000:00:12.5: status 0x4 > kworker/2:2-173 [002] .... 732.609312: ufshcd_exception_event: > 0000:00:12.5: status 0x4 > > Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Reviewed-by: Avri Altman <avri.altman@wdc.com>
On Tue, 2021-02-09 at 08:24 +0200, Adrian Hunter wrote: > # cat /sys/kernel/debug/tracing/trace > # tracer: nop > # > # entries-in-buffer/entries-written: 3/3 #P:5 > # > # _-----=> irqs-off > # / _----=> need-resched > # | / _---=> hardirq/softirq > # || / _--=> preempt-depth > # ||| / delay > # TASK-PID CPU# |||| TIMESTAMP FUNCTION > # | | | |||| | | > kworker/2:2-173 [002] .... 731.486419: > ufshcd_exception_event: 0000:00:12.5: status 0x0 > kworker/2:2-173 [002] .... 732.608918: > ufshcd_exception_event: 0000:00:12.5: status 0x4 > kworker/2:2-173 [002] .... 732.609312: > ufshcd_exception_event: 0000:00:12.5: status 0x4 > > Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Reviewed-by: Bean Huo <beanhuo@micron.com>
diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c index 721f55db181f..d6fdce655388 100644 --- a/drivers/scsi/ufs/ufshcd.c +++ b/drivers/scsi/ufs/ufshcd.c @@ -5616,6 +5616,8 @@ static void ufshcd_exception_event_handler(struct work_struct *work) goto out; } + trace_ufshcd_exception_event(dev_name(hba->dev), status); + status &= hba->ee_ctrl_mask; if (status & MASK_EE_URGENT_BKOPS) diff --git a/include/trace/events/ufs.h b/include/trace/events/ufs.h index e151477d645c..1cb6f1afba0e 100644 --- a/include/trace/events/ufs.h +++ b/include/trace/events/ufs.h @@ -349,6 +349,27 @@ TRACE_EVENT(ufshcd_upiu, ) ); +TRACE_EVENT(ufshcd_exception_event, + + TP_PROTO(const char *dev_name, u16 status), + + TP_ARGS(dev_name, status), + + TP_STRUCT__entry( + __string(dev_name, dev_name) + __field(u16, status) + ), + + TP_fast_assign( + __assign_str(dev_name, dev_name); + __entry->status = status; + ), + + TP_printk("%s: status 0x%x", + __get_str(dev_name), __entry->status + ) +); + #endif /* if !defined(_TRACE_UFS_H) || defined(TRACE_HEADER_MULTI_READ) */ /* This part must be outside protection */
Currently, exception event status can be read from wExceptionEventStatus attribute (sysfs file attributes/exception_event_status under the UFS host controller device directory). Polling that attribute to track UFS exception events is impractical, so add a tracepoint to track exception events for testing and debugging purposes. Note, by the time the exception event status is read, the exception event may have cleared, so the value can be zero - see example below. Note also, only enabled exception events can be reported. A subsequent patch adds the ability for users to enable selected exception events via debugfs. Example with driver instrumented to enable all exception events: # echo 1 > /sys/kernel/debug/tracing/events/ufs/ufshcd_exception_event/enable ... do some I/O ... # cat /sys/kernel/debug/tracing/trace # tracer: nop # # entries-in-buffer/entries-written: 3/3 #P:5 # # _-----=> irqs-off # / _----=> need-resched # | / _---=> hardirq/softirq # || / _--=> preempt-depth # ||| / delay # TASK-PID CPU# |||| TIMESTAMP FUNCTION # | | | |||| | | kworker/2:2-173 [002] .... 731.486419: ufshcd_exception_event: 0000:00:12.5: status 0x0 kworker/2:2-173 [002] .... 732.608918: ufshcd_exception_event: 0000:00:12.5: status 0x4 kworker/2:2-173 [002] .... 732.609312: ufshcd_exception_event: 0000:00:12.5: status 0x4 Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> --- drivers/scsi/ufs/ufshcd.c | 2 ++ include/trace/events/ufs.h | 21 +++++++++++++++++++++ 2 files changed, 23 insertions(+)