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[v3] block: Add ioprio to block_rq tracepoint

Message ID 20240522090104.1751148-1-dongliang.cui@unisoc.com (mailing list archive)
State New
Headers show
Series [v3] block: Add ioprio to block_rq tracepoint | expand

Commit Message

Dongliang Cui May 22, 2024, 9:01 a.m. UTC 
Sometimes we need to track the processing order of requests with
ioprio set. So the ioprio of request can be useful information.

Example：

block_rq_insert: 8,0 WS 4096 () 16573296 + 8 rt,4 [highpool[1]]
block_rq_issue: 8,0 WS 4096 () 16573296 + 8 rt,4 [kworker/7:0H]
block_rq_complete: 8,0 WS () 16573296 + 8 rt,4 [0]

Signed-off-by: Dongliang Cui <dongliang.cui@unisoc.com>
---
Changes in v3:
 - Change the location of the priority macro definition.
---
---
 include/trace/events/block.h | 43 +++++++++++++++++++++++++++---------
 1 file changed, 33 insertions(+), 10 deletions(-)

Comments

Bart Van Assche May 22, 2024, 4:51 p.m. UTC | #1 
On 5/22/24 02:01, Dongliang Cui wrote:
> +#define IOPRIO_CLASS_STRINGS \
> +	{ IOPRIO_CLASS_NONE,	"none" }, \
> +	{ IOPRIO_CLASS_RT,	"rt" }, \
> +	{ IOPRIO_CLASS_BE,	"be" }, \
> +	{ IOPRIO_CLASS_IDLE,	"idle" }, \
> +	{ IOPRIO_CLASS_INVALID,	"invalid"}
> +
>   #ifdef CONFIG_BUFFER_HEAD
>   DECLARE_EVENT_CLASS(block_buffer,
>   
> @@ -82,6 +90,8 @@ TRACE_EVENT(block_rq_requeue,
>   		__field(  dev_t,	dev			)
>   		__field(  sector_t,	sector			)
>   		__field(  unsigned int,	nr_sector		)
> +		__field(  unsigned int,	ioprio_class		)
> +		__field(  unsigned int, ioprio_value		)
>   		__array(  char,		rwbs,	RWBS_LEN	)
>   		__dynamic_array( char,	cmd,	1		)
>   	),
> @@ -90,16 +100,19 @@ TRACE_EVENT(block_rq_requeue,
>   		__entry->dev	   = rq->q->disk ? disk_devt(rq->q->disk) : 0;
>   		__entry->sector    = blk_rq_trace_sector(rq);
>   		__entry->nr_sector = blk_rq_trace_nr_sectors(rq);
> +		__entry->ioprio_class = rq->ioprio >> IOPRIO_CLASS_SHIFT & 0x3;
> +		__entry->ioprio_value = rq->ioprio & 0xff;

Why to split the I/O priority field when storing it in __entry instead of when
the values are printed? Combined the ioprio bitfields occupy 16 bits. The above
patch reserves 64 bits in __entry. I think that's overkill. Additionally, some
bits of the I/O priority bits are discarded by the above code before I/O
priority information is reported.

Please split the I/O priority information into the three fields defined in
include/uapi/linux/ioprio.h (class, hint, prio) and use the macros from that
header file for splitting I/O priority information.

Thanks,

Bart.
diff mbox series

Patch

diff --git a/include/trace/events/block.h b/include/trace/events/block.h
index 0e128ad51460..4563c852ad65 100644
--- a/include/trace/events/block.h
+++ b/include/trace/events/block.h
@@ -9,9 +9,17 @@ 
 #include <linux/blkdev.h>
 #include <linux/buffer_head.h>
 #include <linux/tracepoint.h>
+#include <uapi/linux/ioprio.h>
 
 #define RWBS_LEN	8
 
+#define IOPRIO_CLASS_STRINGS \
+	{ IOPRIO_CLASS_NONE,	"none" }, \
+	{ IOPRIO_CLASS_RT,	"rt" }, \
+	{ IOPRIO_CLASS_BE,	"be" }, \
+	{ IOPRIO_CLASS_IDLE,	"idle" }, \
+	{ IOPRIO_CLASS_INVALID,	"invalid"}
+
 #ifdef CONFIG_BUFFER_HEAD
 DECLARE_EVENT_CLASS(block_buffer,
 
@@ -82,6 +90,8 @@  TRACE_EVENT(block_rq_requeue,
 		__field(  dev_t,	dev			)
 		__field(  sector_t,	sector			)
 		__field(  unsigned int,	nr_sector		)
+		__field(  unsigned int,	ioprio_class		)
+		__field(  unsigned int, ioprio_value		)
 		__array(  char,		rwbs,	RWBS_LEN	)
 		__dynamic_array( char,	cmd,	1		)
 	),
@@ -90,16 +100,19 @@  TRACE_EVENT(block_rq_requeue,
 		__entry->dev	   = rq->q->disk ? disk_devt(rq->q->disk) : 0;
 		__entry->sector    = blk_rq_trace_sector(rq);
 		__entry->nr_sector = blk_rq_trace_nr_sectors(rq);
+		__entry->ioprio_class = rq->ioprio >> IOPRIO_CLASS_SHIFT & 0x3;
+		__entry->ioprio_value = rq->ioprio & 0xff;
 
 		blk_fill_rwbs(__entry->rwbs, rq->cmd_flags);
 		__get_str(cmd)[0] = '\0';
 	),
 
-	TP_printk("%d,%d %s (%s) %llu + %u [%d]",
+	TP_printk("%d,%d %s (%s) %llu + %u %s,%u [%d]",
 		  MAJOR(__entry->dev), MINOR(__entry->dev),
 		  __entry->rwbs, __get_str(cmd),
-		  (unsigned long long)__entry->sector,
-		  __entry->nr_sector, 0)
+		  (unsigned long long)__entry->sector, __entry->nr_sector,
+		  __print_symbolic(__entry->ioprio_class, IOPRIO_CLASS_STRINGS),
+		  __entry->ioprio_value, 0)
 );
 
 DECLARE_EVENT_CLASS(block_rq_completion,
@@ -113,6 +126,8 @@  DECLARE_EVENT_CLASS(block_rq_completion,
 		__field(  sector_t,	sector			)
 		__field(  unsigned int,	nr_sector		)
 		__field(  int	,	error			)
+		__field(  unsigned int,	ioprio_class		)
+		__field(  unsigned int, ioprio_value		)
 		__array(  char,		rwbs,	RWBS_LEN	)
 		__dynamic_array( char,	cmd,	1		)
 	),
@@ -122,16 +137,19 @@  DECLARE_EVENT_CLASS(block_rq_completion,
 		__entry->sector    = blk_rq_pos(rq);
 		__entry->nr_sector = nr_bytes >> 9;
 		__entry->error     = blk_status_to_errno(error);
+		__entry->ioprio_class = rq->ioprio >> IOPRIO_CLASS_SHIFT & 0x3;
+		__entry->ioprio_value = rq->ioprio & 0xff;
 
 		blk_fill_rwbs(__entry->rwbs, rq->cmd_flags);
 		__get_str(cmd)[0] = '\0';
 	),
 
-	TP_printk("%d,%d %s (%s) %llu + %u [%d]",
+	TP_printk("%d,%d %s (%s) %llu + %u %s,%u [%d]",
 		  MAJOR(__entry->dev), MINOR(__entry->dev),
 		  __entry->rwbs, __get_str(cmd),
-		  (unsigned long long)__entry->sector,
-		  __entry->nr_sector, __entry->error)
+		  (unsigned long long)__entry->sector, __entry->nr_sector,
+		  __print_symbolic(__entry->ioprio_class, IOPRIO_CLASS_STRINGS),
+		  __entry->ioprio_value, __entry->error)
 );
 
 /**
@@ -180,8 +198,10 @@  DECLARE_EVENT_CLASS(block_rq,
 		__field(  sector_t,	sector			)
 		__field(  unsigned int,	nr_sector		)
 		__field(  unsigned int,	bytes			)
+		__field(  unsigned int,	ioprio_class		)
+		__field(  unsigned int, ioprio_value		)
 		__array(  char,		rwbs,	RWBS_LEN	)
-		__array(  char,         comm,   TASK_COMM_LEN   )
+		__array(  char,		comm,   TASK_COMM_LEN	)
 		__dynamic_array( char,	cmd,	1		)
 	),
 
@@ -190,17 +210,20 @@  DECLARE_EVENT_CLASS(block_rq,
 		__entry->sector    = blk_rq_trace_sector(rq);
 		__entry->nr_sector = blk_rq_trace_nr_sectors(rq);
 		__entry->bytes     = blk_rq_bytes(rq);
+		__entry->ioprio_class = rq->ioprio >> IOPRIO_CLASS_SHIFT & 0x3;
+		__entry->ioprio_value = rq->ioprio & 0xff;
 
 		blk_fill_rwbs(__entry->rwbs, rq->cmd_flags);
 		__get_str(cmd)[0] = '\0';
 		memcpy(__entry->comm, current->comm, TASK_COMM_LEN);
 	),
 
-	TP_printk("%d,%d %s %u (%s) %llu + %u [%s]",
+	TP_printk("%d,%d %s %u (%s) %llu + %u %s,%u [%s]",
 		  MAJOR(__entry->dev), MINOR(__entry->dev),
 		  __entry->rwbs, __entry->bytes, __get_str(cmd),
-		  (unsigned long long)__entry->sector,
-		  __entry->nr_sector, __entry->comm)
+		  (unsigned long long)__entry->sector, __entry->nr_sector,
+		  __print_symbolic(__entry->ioprio_class, IOPRIO_CLASS_STRINGS),
+		  __entry->ioprio_value, __entry->comm)
 );
 
 /**