From: "Steven Rostedt (VMware)" <rost...@goodmis.org>
Inspecting the data structures of the function graph tracer, I found that
the overrun value is unsigned long, which is 8 bytes on a 64 bit machine,
and not only that, the depth is an int (4 bytes). The overrun can be simply
an unsigned int (4 bytes) and pack the ftrace_graph_ret structure better.
The depth is moved up next to the func, as it is used more often with func,
and improves cache locality.
Signed-off-by: Steven Rostedt (VMware) <rost...@goodmis.org>
---
include/linux/ftrace.h | 4 ++--
kernel/trace/trace_entries.h | 4 ++--
kernel/trace/trace_functions_graph.c | 2 +-
3 files changed, 5 insertions(+), 5 deletions(-)
diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h
index 806196345c3f..8dde9c17aaa5 100644
--- a/include/linux/ftrace.h
+++ b/include/linux/ftrace.h
@@ -864,11 +864,11 @@ struct ftrace_graph_ent {
*/
struct ftrace_graph_ret {
unsigned long func; /* Current function */
+ int depth;
/* Number of functions that overran the depth limit for current task */
- unsigned long overrun;
+ unsigned int overrun;
unsigned long long calltime;
unsigned long long rettime;
- int depth;
} __packed;
/* Type of the callback handlers for tracing function graph*/
diff --git a/kernel/trace/trace_entries.h b/kernel/trace/trace_entries.h
index 18c4a58aff79..ceafe2dc97e1 100644
--- a/kernel/trace/trace_entries.h
+++ b/kernel/trace/trace_entries.h
@@ -93,10 +93,10 @@ FTRACE_ENTRY_PACKED(funcgraph_exit, ftrace_graph_ret_entry,
F_STRUCT(
__field_struct( struct ftrace_graph_ret, ret )
__field_packed( unsigned long, ret, func )
- __field_packed( unsigned long, ret, overrun )
+ __field_packed( int, ret, depth )
+ __field_packed( unsigned int, ret, overrun )
__field_packed( unsigned long long, ret, calltime)
__field_packed( unsigned long long, ret, rettime )
- __field_packed( int, ret, depth )
),
F_printk("<-- %ps (%d) (start: %llx end: %llx) over: %d",
diff --git a/kernel/trace/trace_functions_graph.c
b/kernel/trace/trace_functions_graph.c
index 60d66278aa0d..d874dec87131 100644
--- a/kernel/trace/trace_functions_graph.c
+++ b/kernel/trace/trace_functions_graph.c
@@ -957,7 +957,7 @@ print_graph_return(struct ftrace_graph_ret *trace, struct
trace_seq *s,
/* Overrun */
if (flags & TRACE_GRAPH_PRINT_OVERRUN)
- trace_seq_printf(s, " (Overruns: %lu)\n",
+ trace_seq_printf(s, " (Overruns: %u)\n",
trace->overrun);
print_graph_irq(iter, trace->func, TRACE_GRAPH_RET,
--
2.28.0
