diff options
| author | AKASHI Takahiro <[email protected]> | 2014-04-30 10:54:34 +0100 |
|---|---|---|
| committer | Will Deacon <[email protected]> | 2014-05-29 09:08:33 +0100 |
| commit | bd7d38dbdf356e75eb3b1699158c9b8021fd6784 (patch) | |
| tree | edad0afa91c1774cfaba6319b319d65db244123d /tools/perf/util/scripting-engines/trace-event-python.c | |
| parent | 819e50e25d0ce8a75f5cba815416a6a8573655c4 (diff) | |
arm64: ftrace: Add dynamic ftrace support
This patch allows "dynamic ftrace" if CONFIG_DYNAMIC_FTRACE is enabled.
Here we can turn on and off tracing dynamically per-function base.
On arm64, this is done by patching single branch instruction to _mcount()
inserted by gcc -pg option. The branch is replaced to NOP initially at
kernel start up, and later on, NOP to branch to ftrace_caller() when
enabled or branch to NOP when disabled.
Please note that ftrace_caller() is a counterpart of _mcount() in case of
'static' ftrace.
More details on architecture specific requirements are described in
Documentation/trace/ftrace-design.txt.
Acked-by: Will Deacon <[email protected]>
Signed-off-by: AKASHI Takahiro <[email protected]>
Signed-off-by: Will Deacon <[email protected]>
Diffstat (limited to 'tools/perf/util/scripting-engines/trace-event-python.c')
0 files changed, 0 insertions, 0 deletions