Re: [PATCH v2 02/12] scsi: ufs: add tracing support

[Subhash Jadavani <subhashj@codeaurora.org>]

On 2016-12-13 12:10, Steven Rostedt wrote:
> On Tue, 13 Dec 2016 11:48:45 -0800
> Subhash Jadavani <subhashj@codeaurora.org> wrote:
> 
>> This change adds the ftrace support for following:
>> 1. UFS initialization time
>> 2. Clock gating states
>> 3. Clock scaling states
>> 4. Power management APIs latency
>> 5. BKOPs enable/disable
>> 
>> Usage:
>> 	echo 1 > /sys/kernel/debug/tracing/events/ufs/enable
>> 	cat /sys/kernel/debug/tracing/trace_pipe
>> 
>> Reviewed-by: Sahitya Tummala <stummala@codeaurora.org>
>> Signed-off-by: Subhash Jadavani <subhashj@codeaurora.org>
>> ---
>>  drivers/scsi/ufs/ufshcd.c  | 133 
>> ++++++++++++++++++++++++++++++++++++----
>>  include/trace/events/ufs.h | 149 
>> +++++++++++++++++++++++++++++++++++++++++++++
>>  2 files changed, 270 insertions(+), 12 deletions(-)
>>  create mode 100644 include/trace/events/ufs.h
>> 
>> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
>> index fe516b2..73c5937 100644
>> --- a/drivers/scsi/ufs/ufshcd.c
>> +++ b/drivers/scsi/ufs/ufshcd.c
>> @@ -45,6 +45,9 @@
>>  #include "ufs_quirks.h"
>>  #include "unipro.h"
>> 
>> +#define CREATE_TRACE_POINTS
>> +#include <trace/events/ufs.h>
>> +
>>  #define UFSHCD_REQ_SENSE_SIZE	18
>> 
>>  #define UFSHCD_ENABLE_INTRS	(UTP_TRANSFER_REQ_COMPL |\
>> @@ -721,6 +724,40 @@ static void ufshcd_resume_clkscaling(struct 
>> ufs_hba *hba)
>>  		devfreq_resume_device(hba->devfreq);
>>  }
>> 
>> +static const char *ufschd_uic_link_state_to_string(
>> +			enum uic_link_state state)
>> +{
>> +	switch (state) {
>> +	case UIC_LINK_OFF_STATE:	return "UIC_LINK_OFF_STATE";
>> +	case UIC_LINK_ACTIVE_STATE:	return "UIC_LINK_ACTIVE_STATE";
>> +	case UIC_LINK_HIBERN8_STATE:	return "UIC_LINK_HIBERN8_STATE";
>> +	default:			return "UNKNOWN_STATE";
>> +	}
>> +}
>> +
>> +static const char *ufschd_ufs_dev_pwr_mode_to_string(
>> +			enum ufs_dev_pwr_mode state)
>> +{
>> +	switch (state) {
>> +	case UFS_ACTIVE_PWR_MODE:	return "UFS_ACTIVE_PWR_MODE";
>> +	case UFS_SLEEP_PWR_MODE:	return "UFS_SLEEP_PWR_MODE";
>> +	case UFS_POWERDOWN_PWR_MODE:	return "UFS_POWERDOWN_PWR_MODE";
>> +	default:			return "UNKNOWN_STATE";
>> +	}
>> +}
>> +
>> +static const char *ufschd_clk_gating_state_to_string(
>> +			enum clk_gating_state state)
>> +{
>> +	switch (state) {
>> +	case CLKS_OFF:		return "CLKS_OFF";
>> +	case CLKS_ON:		return "CLKS_ON";
>> +	case REQ_CLKS_OFF:	return "REQ_CLKS_OFF";
>> +	case REQ_CLKS_ON:	return "REQ_CLKS_ON";
>> +	default:		return "UNKNOWN_STATE";
>> +	}
>> +}
>> +
> 
> A much better way than the above is to use the TRACE_DEFINE_ENUM()
> macros in the include/trace/events/ufs.h header. In fact, that's what
> it was made for. Not only will it be much faster to record, it wont
> waste as much space in the ring buffer.
> 
> .e.g.
> 
> #define UFS_LINK_STATES	\
> 	EM( UIC_LINK_OFF_STATE ) \
> 	EM( UIC_LINK_ACTIVE_STATE ) \
> 	EMe(UIC_LINK_HIBERN8_STATE )
> 
> #define UFS_PWR_MODES \
> 	EM( UFS_ACTIVE_PWR_MODE ) \
> 	EM( UFS_SLEEP_PWR_MODE ) \
> 	EM( UFS_POWERDOWN_PWR_MODE) \
> 	EMe(UFS_POWERDOWN_PWR_MODE)
> 
> #define UFSCHD_CLK_GATING_STATES \
> 	EM( CLKS_OFF) \
> 	EM( CLKS_ON) \
> 	EM( REQ_CLKS_OFF) \
> 	EMe(REQ_CLKS_ON)
> 
> #undef EM
> #undef EMe
> 
> #define EM(a)	TRACE_DEFINE_ENUM(a);
> #define EMe(a)	TRACE_DEFINE_ENUM(a);
> 
> UFS_LINK_STATES
> UFS_PWR_MODES
> UFSCHD_CLK_GATING_STATES
> 
> #undef EM
> #undef EMe
> 
> #define EM(a)	{ a, #a },
> #define EMe(a)	{ a, #a }
> 
> 
> DECLARE_EVENT_CLASS(ufshcd_template,
> 	TP_PROTO(const char *dev_name int err, s64 usecs,
> 		 int state, int link_state);
> 
> 	[..]
> 
> 	TP_printk(
> 		"%s: took %lld, dev_state: %s, link_state: %s, err %d",
> 		get_str(dev_name),
> 		__entry->usecs,
> 		__print_symbolic(__entry->state, UFS_PWR_MODES),
> 		__print_symbolic(__entry->link_state, UFS_LINK_STATES),
> 		__entry->err
> 	)
> 
> Not to mention, I think some of the strings may not be matching what
> was passed in.

Thanks for the suggestion. Let me check this.

> 
> -- Steve
> 
> 
> 
>> +DECLARE_EVENT_CLASS(ufshcd_template,
>> +	TP_PROTO(const char *dev_name, int err, s64 usecs,
>> +		 const char *dev_state, const char *link_state),
>> +
>> +	TP_ARGS(dev_name, err, usecs, dev_state, link_state),
>> +
>> +	TP_STRUCT__entry(
>> +		__field(s64, usecs)
>> +		__field(int, err)
>> +		__string(dev_name, dev_name)
>> +		__string(dev_state, dev_state)
>> +		__string(link_state, link_state)
>> +	),
>> +
>> +	TP_fast_assign(
>> +		__entry->usecs = usecs;
>> +		__entry->err = err;
>> +		__assign_str(dev_name, dev_name);
>> +		__assign_str(dev_state, dev_state);
>> +		__assign_str(link_state, link_state);
>> +	),
>> +
>> +	TP_printk(
>> +		"%s: took %lld usecs, dev_state: %s, link_state: %s, err %d",
>> +		__get_str(dev_name),
>> +		__entry->usecs,
>> +		__get_str(dev_state),
>> +		__get_str(link_state),
>> +		__entry->err
>> +	)
>> +);
>> +
>> +DEFINE_EVENT(ufshcd_template, ufshcd_system_suspend,
>> +	     TP_PROTO(const char *dev_name, int err, s64 usecs,
>> +		      const char *dev_state, const char *link_state),
>> +	     TP_ARGS(dev_name, err, usecs, dev_state, link_state));
>> +
>> +DEFINE_EVENT(ufshcd_template, ufshcd_system_resume,
>> +	     TP_PROTO(const char *dev_name, int err, s64 usecs,
>> +		      const char *dev_state, const char *link_state),
>> +	     TP_ARGS(dev_name, err, usecs, dev_state, link_state));
>> +
>> +DEFINE_EVENT(ufshcd_template, ufshcd_runtime_suspend,
>> +	     TP_PROTO(const char *dev_name, int err, s64 usecs,
>> +		      const char *dev_state, const char *link_state),
>> +	     TP_ARGS(dev_name, err, usecs, dev_state, link_state));
>> +
>> +DEFINE_EVENT(ufshcd_template, ufshcd_runtime_resume,
>> +	     TP_PROTO(const char *dev_name, int err, s64 usecs,
>> +		      const char *dev_state, const char *link_state),
>> +	     TP_ARGS(dev_name, err, usecs, dev_state, link_state));
>> +
>> +DEFINE_EVENT(ufshcd_template, ufshcd_init,
>> +	     TP_PROTO(const char *dev_name, int err, s64 usecs,
>> +		      const char *dev_state, const char *link_state),
>> +	     TP_ARGS(dev_name, err, usecs, dev_state, link_state));
>> +#endif /* if !defined(_TRACE_UFS_H) || 
>> defined(TRACE_HEADER_MULTI_READ) */
>> +
>> +/* This part must be outside protection */
>> +#include <trace/define_trace.h>

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