| Message ID | 1495036020-30551-1-git-send-email-Liam.Howlett@Oracle.com |
|---|---|
| State | Accepted |
| Delegated to: | David Miller |
| Headers | show |
From: "Liam R. Howlett" <Liam.Howlett@Oracle.com> Date: Wed, 17 May 2017 11:47:00 -0400 > The ftrace function_graph time measurements of a given function is not > accurate according to those recorded by ftrace using the function > filters. This change pulls the x86_64 fix from 'commit 722b3c746953 > ("ftrace/graph: Trace function entry before updating index")' into the > sparc specific prepare_ftrace_return which stops ftrace from > counting interrupted tasks in the time measurement. > > Example measurements for select_task_rq_fair running "hackbench 100 > process 1000": > > | tracing/trace_stat/function0 | function_graph > Before patch | 2.802 us | 4.255 us > After patch | 2.749 us | 3.094 us > > Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com> Applied, thanks. -- To unsubscribe from this list: send the line "unsubscribe sparclinux" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/arch/sparc/kernel/ftrace.c b/arch/sparc/kernel/ftrace.c index 6bcff69..cec54dc 100644 --- a/arch/sparc/kernel/ftrace.c +++ b/arch/sparc/kernel/ftrace.c @@ -130,17 +130,16 @@ unsigned long prepare_ftrace_return(unsigned long parent, if (unlikely(atomic_read(¤t->tracing_graph_pause))) return parent + 8UL; - if (ftrace_push_return_trace(parent, self_addr, &trace.depth, - frame_pointer, NULL) == -EBUSY) - return parent + 8UL; - trace.func = self_addr; + trace.depth = current->curr_ret_stack + 1; /* Only trace if the calling function expects to */ - if (!ftrace_graph_entry(&trace)) { - current->curr_ret_stack--; + if (!ftrace_graph_entry(&trace)) + return parent + 8UL; + + if (ftrace_push_return_trace(parent, self_addr, &trace.depth, + frame_pointer, NULL) == -EBUSY) return parent + 8UL; - } return return_hooker; }
The ftrace function_graph time measurements of a given function is not accurate according to those recorded by ftrace using the function filters. This change pulls the x86_64 fix from 'commit 722b3c746953 ("ftrace/graph: Trace function entry before updating index")' into the sparc specific prepare_ftrace_return which stops ftrace from counting interrupted tasks in the time measurement. Example measurements for select_task_rq_fair running "hackbench 100 process 1000": | tracing/trace_stat/function0 | function_graph Before patch | 2.802 us | 4.255 us After patch | 2.749 us | 3.094 us Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com> --- arch/sparc/kernel/ftrace.c | 13 ++++++------- 1 file changed, 6 insertions(+), 7 deletions(-)