On Wed Sep 11, 2024 at 11:53 AM EEST, Roberto Sassu wrote:
> I made few measurements. I have a Fedora 38 VM with TPM passthrough.
I was thinking more like
sudo bpftrace -e 'k:tpm_transmit { @start[tid] = nsecs; } kr:tpm_transmit { @[kstack, ustack, comm] = sum(nsecs - @start[tid]); delete(@start[tid]); } END { clear(@start); }'
For example when running "tpm2_createprimary --hierarchy o -G rsa2048 -c owner.txt", I get:
Attaching 3 probes...
^C
@[
tpm_transmit_cmd+46
tpm2_flush_context+120
tpm2_commit_space+197
tpm_dev_transmit.constprop.0+137
tpm_dev_async_work+102
process_one_work+374
worker_thread+614
kthread+207
ret_from_fork+49
ret_from_fork_asm+26
, , kworker/4:2]: 2860677
@[
tpm_dev_transmit.constprop.0+111
tpm_dev_async_work+102
process_one_work+374
worker_thread+614
kthread+207
ret_from_fork+49
ret_from_fork_asm+26
, , kworker/16:1]: 3890693
@[
tpm_transmit_cmd+46
tpm2_load_context+195
tpm2_prepare_space+410
tpm_dev_transmit.constprop.0+54
tpm_dev_async_work+102
process_one_work+374
worker_thread+614
kthread+207
ret_from_fork+49
ret_from_fork_asm+26
, , kworker/4:2]: 9058524
@[
tpm_transmit_cmd+46
tpm2_save_context+179
tpm2_commit_space+314
tpm_dev_transmit.constprop.0+137
tpm_dev_async_work+102
process_one_work+374
worker_thread+614
kthread+207
ret_from_fork+49
ret_from_fork_asm+26
, , kworker/4:2]: 11426260
@[
tpm_transmit_cmd+46
tpm2_load_context+195
tpm2_prepare_space+318
tpm_dev_transmit.constprop.0+54
tpm_dev_async_work+102
process_one_work+374
worker_thread+614
kthread+207
ret_from_fork+49
ret_from_fork_asm+26
, , kworker/4:2]: 14182972
@[
tpm_transmit_cmd+46
tpm2_save_context+179
tpm2_commit_space+155
tpm_dev_transmit.constprop.0+137
tpm_dev_async_work+102
process_one_work+374
worker_thread+614
kthread+207
ret_from_fork+49
ret_from_fork_asm+26
, , kworker/4:2]: 22597059
@[
tpm_dev_transmit.constprop.0+111
tpm_dev_async_work+102
process_one_work+374
worker_thread+614
kthread+207
ret_from_fork+49
ret_from_fork_asm+26
, , kworker/4:2]: 1958500581
This results stacks to compare with "real" time spent total in each
stack (in nsecs). CPU time is relevant measure in the problem we're
dealing.
BR, Jarkko
