Hi,
This patch logs the reference data collected using the trace events
framework. To enable capturing the trace, insert the module and mount
debugfs.
# modprobe memref
# echo "memtrace:memtrace" > /debug/tracing/set_event
# echo 1 > /debug/tracing/events/memtrace/memtrace/enable
# echo 1 > /debug/tracing/tracing_on
# echo 1 > /debug/tracing/tracing_enable
# cat /debug/tracing/trace
#
# TASK-PID CPU# TIMESTAMP FUNCTION
# | | | | |
memref-4402 [000] 250.274467: memtrace: 2115 6208 1
memref-4402 [000] 250.274467: memtrace: 2115 6272 0
memref-4402 [000] 250.274467: memtrace: 2115 6336 0
memref-4402 [000] 250.274467: memtrace: 2115 6400 1
| | |
V | V
sample number | whether referenced
| or not
V
physical address of the
start of the block in MB
sample number is a monotonically increasing unique count associated with
a sample. Time stamp is for trace printing not access. The entire access
pattern for all blocks will be at each interval (10ms default).
This data can be post-processed by scripts to generate the overall memory
reference pattern for a given amount of time. Temporal and spatial
reference pattern can be obtained.
This is a statistical sample where any number of reference to a block
over the sampling interval is just marked as one.
Signed-off-by: Ankita Garg <ankita@xxxxxxxxxx>
---
include/trace/events/memtrace.h | 28 ++++++++++++++++++++++++++++
lib/memtrace.c | 4 ++++
2 files changed, 32 insertions(+), 0 deletions(-)
create mode 100644 include/trace/events/memtrace.h
diff --git a/include/trace/events/memtrace.h b/include/trace/events/memtrace.h
new file mode 100644
index 0000000..8a6cdd6
--- /dev/null
+++ b/include/trace/events/memtrace.h
@@ -0,0 +1,28 @@
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM memtrace
+
+#include <linux/tracepoint.h>
+
+#if !defined(_TRACE_MEMTRACE_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_MEMTRACE_H
+
+TRACE_EVENT(memtrace,
+ TP_PROTO(unsigned int seq, unsigned long base, unsigned long access_flag),
+ TP_ARGS(seq, base, access_flag),
+ TP_STRUCT__entry(
+ __field( unsigned int , seq )
+ __field( unsigned long, base )
+ __field( unsigned long, access_flag )
+ ),
+ TP_fast_assign(
+ __entry->seq = seq;
+ __entry->base = base;
+ __entry->access_flag = access_flag;
+ ),
+ TP_printk("%u %lu %lu", __entry->seq, __entry->base, __entry->access_flag)
+);
+
+#endif /* _TRACE_MEMTRACE_H */
+
+/* This part must be outside protection */
+#include <trace/define_trace.h>
diff --git a/lib/memtrace.c b/lib/memtrace.c
index aec5b65..e9cb967 100644
--- a/lib/memtrace.c
+++ b/lib/memtrace.c
@@ -3,6 +3,9 @@
#include <linux/module.h>
#include <linux/mm.h>
+#define CREATE_TRACE_POINTS
+#include <trace/events/memtrace.h>
+
/* Trace Unique identifier */
atomic_t trace_sequence_number;
pid_t pg_trace_pid;
@@ -195,6 +198,7 @@ void update_and_log_data(void)
* Can modify to dump only blocks that have been marked
* accessed
*/
+ trace_memtrace(seq, base_addr, access_flag);
memtrace_block_accessed[i].access_flag = 0;
}
--
1.7.4
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