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Iotrace improvements

PATCH Superseded Ramon Fried 2 participants 7 messages May 24, 2018 – May 26, 2018

v1 of 5 Superseded Latest is v5 →

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#0 lore raw

cover Iotrace improvements

These set of patches add few improvements to iotrace.
* Region limiting - allows setting an address and size where only
io operations that falls into that address are logged.
* Timestamping - Timestamp every iotrace record with current timestamp
* dumping - iotrace dump command for dumping all records from buffer
in a readable fashion.

In terms of backwards compatibility, the timestamp is not backward compatible as it changes the iotrace record. so if one developed an offline parsing tool it will be broken.
I though of adding #ifdef specific for that, but eventually I didn't.

Ramon Fried (5):
cmd: iotrace: add set region command
iotrace: add IO region limit
common: iotrace: add timestamp to iotrace records
iotrace: move record definitons to header file
cmd: iotrace: add dump trace command

 cmd/iotrace.c     | 58 ++++++++++++++++++++++++++++++++++++++++++++++-
 common/iotrace.c  | 53 +++++++++++++++++++++++--------------------
 include/iotrace.h | 52 ++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 137 insertions(+), 26 deletions(-)
Signature · 1 line
2.17.0
#1 lore raw

PATCH 1/5 cmd: iotrace: add set region command

---
 cmd/iotrace.c | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)
cmd/iotrace.c +22 -0
index e496787e0d..601b8c8e32 100644
@@ -15,6 +15,9 @@ static void do_print_stats(void)
 	iotrace_get_buffer(&start, &size, &offset, &count);
 	printf("Start:  %08lx\n", start);
 	printf("Size:   %08lx\n", size);
+	iotrace_get_region(&start, &size);
+	printf("Region: %08lx\n", start);
+	printf("Size:   %08lx\n", size);
 	printf("Offset: %08lx\n", offset);
 	printf("Output: %08lx\n", start + offset);
 	printf("Count:  %08lx\n", count);
@@ -37,6 +40,22 @@ static int do_set_buffer(int argc, char * const argv[])
 	return 0;
 }
 
+static int do_set_region(int argc, char * const argv[])
+{
+	ulong addr = 0, size = 0;
+
+	if (argc == 2) {
+		addr = simple_strtoul(*argv++, NULL, 16);
+		size = simple_strtoul(*argv++, NULL, 16);
+	} else if (argc != 0) {
+		return CMD_RET_USAGE;
+	}
+
+	iotrace_set_region(addr, size);
+
+	return 0;
+}
+
 int do_iotrace(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
 {
 	const char *cmd = argc < 2 ? NULL : argv[1];
@@ -46,6 +65,8 @@ int do_iotrace(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
 	switch (*cmd) {
 	case 'b':
 		return do_set_buffer(argc - 2, argv + 2);
+	case 'l':
+		return do_set_region(argc - 2, argv + 2);
 	case 'p':
 		iotrace_set_enabled(0);
 		break;
@@ -67,6 +88,7 @@ U_BOOT_CMD(
 	"iotrace utility commands",
 	"stats                        - display iotrace stats\n"
 	"iotrace buffer <address> <size>      - set iotrace buffer\n"
+	"iotrace limit <address> <size>       - set iotrace region limit\n"
 	"iotrace pause                        - pause tracing\n"
 	"iotrace resume                       - resume tracing"
 );
Signature · 1 line
2.17.0
#2 lore raw

PATCH 2/5 iotrace: add IO region limit

In reply to Ramon Fried

When dealing with a lot of IO regions, sometimes
it makes sense only to trace a specific one.
This patch adds support for region limits.
If region is not set, the iotrace works the same as it was. If region is set, the iotrace only logs io operation that falls in the defined region.

---
 common/iotrace.c  | 27 +++++++++++++++++++++++++++
 include/iotrace.h | 24 ++++++++++++++++++++++++
 2 files changed, 51 insertions(+)
common/iotrace.c +27 -0
index b16b0d612d..f39885663a 100644
@@ -42,6 +42,8 @@ struct iotrace_record {
  * @start:	Start address of iotrace buffer
  * @size:	Size of iotrace buffer in bytes
  * @offset:	Current write offset into iotrace buffer
+ * @region_start: Address of IO region to trace
+ * @region_size: Size of region to trace. if 0 will trace all address space
  * @crc32:	Current value of CRC chceksum of trace records
  * @enabled:	true if enabled, false if disabled
  */
@@ -49,6 +51,8 @@ static struct iotrace {
 	ulong start;
 	ulong size;
 	ulong offset;
+	ulong region_start;
+	ulong region_size;
 	u32 crc32;
 	bool enabled;
 } iotrace;
@@ -66,6 +70,11 @@ static void add_record(int flags, const void *ptr, ulong value)
 	if (!(gd->flags & GD_FLG_RELOC) || !iotrace.enabled)
 		return;
 
+	if (iotrace.region_size)
+		if ((ulong)ptr < iotrace.region_start ||
+		    (ulong)ptr > iotrace.region_start + iotrace.region_size)
+			return;
+
 	/* Store it if there is room */
 	if (iotrace.offset + sizeof(*rec) < iotrace.size) {
 		rec = (struct iotrace_record *)map_sysmem(
@@ -142,6 +151,24 @@ u32 iotrace_get_checksum(void)
 	return iotrace.crc32;
 }
 
+void iotrace_set_region(ulong start, ulong size)
+{
+	iotrace.region_start = start;
+	iotrace.region_size = size;
+}
+
+void iotrace_reset_region(void)
+{
+	iotrace.region_start = 0;
+	iotrace.region_size = 0;
+}
+
+void iotrace_get_region(ulong *start, ulong *size)
+{
+	*start = iotrace.region_start;
+	*size = iotrace.region_size;
+}
+
 void iotrace_set_enabled(int enable)
 {
 	iotrace.enabled = enable;
include/iotrace.h +24 -0
index 9fe5733f87..1efb117343 100644
@@ -58,6 +58,30 @@ void iotrace_reset_checksum(void);
  */
 u32 iotrace_get_checksum(void);
 
+/**
+ * iotrace_set_region() - Set whether iotrace is limited to a specific
+ * io region.
+ *
+ * Defines the address and size of the limited region.
+ *
+ * @start: address of the beginning of the region
+ * @size: size of the region in bytes.
+ */
+void iotrace_set_region(ulong start, ulong size);
+
+/**
+ * iotrace_reset_region() - Reset the region limit
+ */
+void iotrace_reset_region(void);
+
+/**
+ * iotrace_get_region() - Get region information
+ *
+ * @start: Returns start address of region
+ * @size: Returns size of region in bytes
+ */
+void iotrace_get_region(ulong *start, ulong *size);
+
 /**
  * iotrace_set_enabled() - Set whether iotracing is enabled or not
  *
Signature · 1 line
2.17.0
#3 lore raw

PATCH 3/5 common: iotrace: add timestamp to iotrace records

In reply to Ramon Fried

Add timestamp to each iotrace record to aid in debugging of IO timing access bugs.

---
 common/iotrace.c | 3 +++
 1 file changed, 3 insertions(+)
common/iotrace.c +3 -0
index f39885663a..3530688ab1 100644
@@ -27,11 +27,13 @@ enum iotrace_flags {
  * struct iotrace_record - Holds a single I/O trace record
  *
  * @flags: I/O access type
+ * @timestamp: Timestamp of access
  * @addr: Address of access
  * @value: Value written or read
  */
 struct iotrace_record {
 	enum iotrace_flags flags;
+	u64 timestamp;
 	phys_addr_t addr;
 	iovalue_t value;
 };
@@ -82,6 +84,7 @@ static void add_record(int flags, const void *ptr, ulong value)
 					sizeof(value));
 	}
 
+	rec->timestamp = get_ticks();
 	rec->flags = flags;
 	rec->addr = map_to_sysmem(ptr);
 	rec->value = value;
Signature · 1 line
2.17.0
#4 lore raw

PATCH 4/5 iotrace: move record definitons to header file

In reply to Ramon Fried

The header definitions are needed for reading
record information in cmd/iotrace.c

---
 common/iotrace.c  | 27 ---------------------------
 include/iotrace.h | 28 ++++++++++++++++++++++++++++
 2 files changed, 28 insertions(+), 27 deletions(-)
common/iotrace.c +0 -27
index 3530688ab1..74408a5dbb 100644
@@ -11,33 +11,6 @@
 
 DECLARE_GLOBAL_DATA_PTR;
 
-/* Support up to the machine word length for now */
-typedef ulong iovalue_t;
-
-enum iotrace_flags {
-	IOT_8 = 0,
-	IOT_16,
-	IOT_32,
-
-	IOT_READ = 0 << 3,
-	IOT_WRITE = 1 << 3,
-};
-
-/**
- * struct iotrace_record - Holds a single I/O trace record
- *
- * @flags: I/O access type
- * @timestamp: Timestamp of access
- * @addr: Address of access
- * @value: Value written or read
- */
-struct iotrace_record {
-	enum iotrace_flags flags;
-	u64 timestamp;
-	phys_addr_t addr;
-	iovalue_t value;
-};
-
 /**
  * struct iotrace - current trace status and checksum
  *
include/iotrace.h +28 -0
index 1efb117343..b6e006ced0 100644
@@ -7,6 +7,34 @@
 #define __IOTRACE_H
 
 #include <linux/types.h>
+#include <common.h>
+
+/* Support up to the machine word length for now */
+typedef ulong iovalue_t;
+
+enum iotrace_flags {
+	IOT_8 = 0,
+	IOT_16,
+	IOT_32,
+
+	IOT_READ = 0 << 3,
+	IOT_WRITE = 1 << 3,
+};
+
+/**
+ * struct iotrace_record - Holds a single I/O trace record
+ *
+ * @flags: I/O access type
+ * @timestamp: Timestamp of access
+ * @addr: Address of access
+ * @value: Value written or read
+ */
+struct iotrace_record {
+	enum iotrace_flags flags;
+	u64 timestamp;
+	phys_addr_t addr;
+	iovalue_t value;
+};
 
 /*
  * This file is designed to be included in arch/<arch>/include/asm/io.h.
Signature · 1 line
2.17.0
#5 lore raw

PATCH 5/5 cmd: iotrace: add dump trace command

In reply to Ramon Fried

Add dump trace command which dump all trace
buffer content in a much more readable fashion
than md.

---
 cmd/iotrace.c | 36 +++++++++++++++++++++++++++++++++++-
 1 file changed, 35 insertions(+), 1 deletion(-)
cmd/iotrace.c +35 -1
index 601b8c8e32..f98eb54234 100644
@@ -24,6 +24,36 @@ static void do_print_stats(void)
 	printf("CRC32:  %08lx\n", (ulong)iotrace_get_checksum());
 }
 
+static void do_print_trace(void)
+{
+	ulong start, size, offset, count;
+
+	struct iotrace_record *cur_record;
+
+	iotrace_get_buffer(&start, &size, &offset, &count);
+
+	if (!start || !size || !count)
+		return;
+
+	printf("Timestamp  Value          Address\n");
+
+	cur_record = (struct iotrace_record *)start;
+	for (int i = 0; i < count; i++) {
+		if (cur_record->flags & IOT_WRITE)
+			printf("%08llu: 0x%08lx --> 0x%lx08\n",
+			       cur_record->timestamp,
+					cur_record->value,
+					cur_record->addr);
+		else
+			printf("%08llu: 0x%08lx <-- 0x%lx08\n",
+			       cur_record->timestamp,
+					cur_record->value,
+					cur_record->addr);
+
+		cur_record++;
+	}
+}
+
 static int do_set_buffer(int argc, char * const argv[])
 {
 	ulong addr = 0, size = 0;
@@ -76,6 +106,9 @@ int do_iotrace(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
 	case 's':
 		do_print_stats();
 		break;
+	case 'd':
+		do_print_trace();
+		break;
 	default:
 		return CMD_RET_USAGE;
 	}
@@ -90,5 +123,6 @@ U_BOOT_CMD(
 	"iotrace buffer <address> <size>      - set iotrace buffer\n"
 	"iotrace limit <address> <size>       - set iotrace region limit\n"
 	"iotrace pause                        - pause tracing\n"
-	"iotrace resume                       - resume tracing"
+	"iotrace resume                       - resume tracing\n"
+	"iotrace dump                         - dump iotrace buffer"
 );
Signature · 1 line
2.17.0
#6 lore raw

PATCH 5/5 cmd: iotrace: add dump trace command

Hi Ramon,

Quoted 9 lines · Ramon Fried

Add dump trace command which dump all trace
buffer content in a much more readable fashion
than md.

---
 cmd/iotrace.c | 36 +++++++++++++++++++++++++++++++++++-
 1 file changed, 35 insertions(+), 1 deletion(-)

Please see bootstage - I think the timestamp should be in microseconds.

Regards,
Simon