disable Wno-error=unused-but-set-variable
just delete -Wall
build kernel
export CROSS_COMPILE=aarch64-linux-android-
export ARCH=arm64
export CROSS_COMPILE_ARM32=/media/alex/08387397-8c9b-4a7c-8e14-e2cae7e0922c/aosp-9-r10/prebuilts/gcc/linux-x86/arm/arm-linux-androideabi-4.9/bin/arm-linux-androideabi-
sed -i "s/\-Wall / /g" `grep "\-Wall " -rl ./` # avoid warning to corrupt compile
# after compile kernel
cp ./arch/arm64/boot/Image.gz-dtb /media/alex/08387397-8c9b-4a7c-8e14-e2cae7e0922c/aosp-9-r10/device/google/wahoo-kernel
do as google say:
https://source.android.com/devices/tech/debug/ftrace#dftrace
linux official doc:
https://www.kernel.org/doc/Documentation/trace/ftrace.txt
then I find ftrace doesn't work well on android, after some time try. I find linux kernel can log all functions, while android cann't. I find a way to work arround it
walleye:/d/tracing # echo ip_* > set_ftrace_filter # all ip_* function are traced
walleye:/d/tracing # echo function_graph > current_tracer
walleye:/d/tracing # echo 1 > tracing_on #curl www.baidu.com
walleye:/d/tracing # echo 0 > tracing_on
walleye:/d/tracing # cat trace
# tracer: function_graph
#
# CPU DURATION FUNCTION CALLS
# | | | | | | |
7) ! 379.114 us | ip_local_deliver();
7) + 80.729 us | ip_local_deliver();
7) ! 172.292 us | ip_local_deliver();
7) ! 108.698 us | ip_local_deliver();
7) ! 133.125 us | ip_local_deliver();
7) ! 121.667 us | ip_local_deliver();
7) ! 174.844 us | ip_local_deliver();
0) 2.448 us | ip_mc_drop_socket();
0) 2.708 us | ip_mc_drop_socket();
1) 3.021 us | ip_mc_drop_socket();
1) | ip_queue_xmit() {
1) | ip_local_out() {
1) | ip_output() {
1) | ip_finish_output() {
1) ! 197.135 us | ip_finish_output2();
1) ! 202.656 us | }
1) ! 271.093 us | }
1) ! 417.969 us | }
1) ! 427.552 us | }
------------------------------------------
1) OkHttp -3302 => -0
------------------------------------------
1) | ip_queue_xmit() {
1) | ip_local_out() {
1) | ip_output() {
1) | ip_finish_output() {
1) ! 246.146 us | ip_finish_output2();
1) ! 254.531 us | }
1) ! 292.865 us | }
1) ! 463.438 us | }
1) ! 471.354 us | }
7) | ip_rcv() {
7) | ip_rcv_finish() {
7) | ip_local_deliver() {
7) + 74.583 us | ip_local_deliver_finish();
7) ! 129.167 us | }
7) ! 141.406 us | }
7) ! 211.146 us | }
7) | ip_rcv() {
7) | ip_rcv_finish() {
7) + 29.532 us | ip_route_input_noref();
7) | ip_local_deliver() {
7) + 26.666 us | ip_local_deliver_finish();
7) + 72.239 us | }
7) ! 116.979 us | }
7) ! 171.198 us | }
------------------------------------------
1) -0 => [email protected]
------------------------------------------
1) 2.395 us | ip_mc_drop_socket();
2) 2.708 us | ip_mc_drop_socket();
------------------------------------------
1) [email protected] => netlink-942
------------------------------------------
1) 1.823 us | ip_mc_drop_socket();
------------------------------------------
7) cds_ol_-2461 => netlink-942
------------------------------------------
7) 1.667 us | ip_mc_drop_socket();
0) 2.500 us | ip_mc_drop_socket();
------------------------------------------
7) netlink-942 => curl-3351
------------------------------------------
7) 1.823 us | ip_mc_drop_socket();
------------------------------------------
0) [email protected] => netd-3353
------------------------------------------
0) 3.073 us | ip_generic_getfrag();
------------------------------------------
7) curl-3351 => netd-3353
------------------------------------------
7) 2.031 us | ip_mc_drop_socket();
7) + 15.313 us | ip_route_output_flow();
7) 0.417 us | ip_mc_drop_socket();
7) 3.854 us | ip_route_output_flow();
7) 0.521 us | ip_mc_drop_socket();
4) 7.188 us | ip_route_output_flow();
4) 3.855 us | ip_route_output_flow();
4) | ip_queue_xmit() {
4) | ip_local_out() {
4) | ip_output() {
4) | ip_finish_output() {
4) ! 256.875 us | ip_finish_output2();
4) ! 263.490 us | }
4) ! 319.791 us | }
4) ! 466.875 us | }
4) ! 473.646 us | }
------------------------------------------
7) netd-3353 => cds_ol_-2461
------------------------------------------
7) | ip_rcv() {
7) | ip_rcv_finish() {
7) + 18.906 us | ip_route_input_noref();
7) | ip_local_deliver() {
7) | ip_local_deliver_finish() {
7) ! 121.666 us | ip_queue_xmit();
7) ! 261.979 us | }
7) ! 310.885 us | }
7) ! 343.281 us | }
7) ! 403.802 us | }
4) | ip_queue_xmit() {
4) | ip_local_out() {
4) | ip_output() {
4) | ip_finish_output() {
4) + 51.927 us | ip_finish_output2();
4) + 57.604 us | }
4) + 80.469 us | }
4) ! 147.813 us | }
4) ! 153.489 us | }
7) | ip_rcv() {
7) | ip_rcv_finish() {
7) | ip_local_deliver() {
7) + 63.177 us | ip_local_deliver_finish();
7) ! 109.323 us | }
7) ! 121.302 us | }
7) ! 171.927 us | }
7) | ip_rcv() {
7) | ip_rcv_finish() {
7) | ip_local_deliver() {
7) | ip_local_deliver_finish() {
7) ! 133.542 us | ip_queue_xmit();
7) ! 200.417 us | }
7) ! 297.448 us | }
7) ! 308.803 us | }
7) ! 342.657 us | }
7) | ip_rcv() {
7) | ip_rcv_finish() {
7) | ip_local_deliver() {
7) | ip_local_deliver_finish() {
7) ! 115.834 us | ip_queue_xmit();
7) ! 176.198 us | }
7) ! 217.604 us | }
7) ! 226.354 us | }
7) ! 265.208 us | }
7) | ip_rcv() {
7) | ip_rcv_finish() {
7) | ip_local_deliver() {
7) | ip_local_deliver_finish() {
7) ! 106.510 us | ip_queue_xmit();
7) ! 160.000 us | }
7) ! 195.313 us | }
7) ! 202.084 us | }
7) ! 240.833 us | }
------------------------------------------
7) cds_ol_-2461 => curl-3351
------------------------------------------
7) 1.562 us | ip_mc_drop_socket();
7) | ip_queue_xmit() {
7) | ip_local_out() {
7) | ip_output() {
7) | ip_finish_output() {
7) + 44.218 us | ip_finish_output2();
7) + 49.114 us | }
7) + 72.292 us | }
7) ! 126.927 us | }
7) ! 132.761 us | }
------------------------------------------
That's all