On Wed, Aug 06, 2025 at 11:20:08AM +0100, Mark Rutland wrote:
> On Sat, Aug 02, 2025 at 11:26:46PM +0200, Jiri Olsa wrote:
> > On Fri, Aug 01, 2025 at 10:49:56AM +0100, Mark Rutland wrote:
> > > On Wed, Jul 30, 2025 at 01:19:51PM +0200, Jiri Olsa wrote:
> > > > On Tue, Jul 29, 2025 at 06:57:40PM +0100, Mark Rutland wrote:
> > > > >
> > > > > On Tue, Jul 29, 2025 at 12:28:03PM +0200, Jiri Olsa wrote:
> > > > > > hi,
> > > > > > while poking the multi-tracing interface I ended up with just one
> > > > > > ftrace_ops object to attach all trampolines.
> > > > > >
> > > > > > This change allows to use less direct API calls during the
> > > > > > attachment
> > > > > > changes in the future code, so in effect speeding up the attachment.
> > > > >
> > > > > How important is that, and what sort of speedup does this result in? I
> > > > > ask due to potential performance hits noted below, and I'm lacking
> > > > > context as to why we want to do this in the first place -- what is
> > > > > this
> > > > > intended to enable/improve?
> > > >
> > > > so it's all work on PoC stage, the idea is to be able to attach many
> > > > (like 20,30,40k) functions to their trampolines quickly, which at the
> > > > moment is slow because all the involved interfaces work with just single
> > > > function/tracempoline relation
> > >
> > > Do you know which aspect of that is slow? e.g. is that becuase you have
> > > to update each ftrace_ops independently, and pay the synchronization
> > > overhead per-ops?
> > >
> > > I ask because it might be possible to do some more batching there, at
> > > least for architectures like arm64 that use the CALL_OPS approach.
> >
> > IIRC it's the rcu sync in register_ftrace_direct and ftrace_shutdown
> > I'll try to profile that case again, there might have been changes
> > since the last time we did that
>
> Do you mean synchronize_rcu_tasks()?
>
> The call in register_ftrace_direct() was removed in commit:
>
> 33f137143e651321 ("ftrace: Use asynchronous grace period for
> register_ftrace_direct()")
>
> ... but in ftrace_shutdown() we still have a call to synchronize_rcu_tasks(),
> and to synchronize_rcu_tasks_rude().
>
> The call to synchronize_rcu_tasks() is still necessary, but we might be
> abel to batch that better with API changes.
>
> I think we might be able to remove the call to
> synchronize_rcu_tasks_rude() on architectures with ARCH_WANTS_NO_INSTR,
> since there shouldn't be any instrumentable functions called with RCU
> not watching. That'd need to be checked.
>
> [...]
>
> > > > sorry I probably forgot/missed discussion on this, but doing the fast
> > > > path like in
> > > > x86_64 is not an option in arm, right?
> > >
> > > On arm64 we have a fast path, BUT branch range limitations means that we
> > > cannot always branch directly from the instrumented function to the
> > > direct func with a single branch instruction. We use ops->direct_call to
> > > handle that case within a common trampoline, which is significantly
> > > cheaper that iterating over the ops and/or looking up the direct func
> > > from a hash.
> > >
> > > With CALL_OPS, we place a pointer to the ops immediately before the
> > > instrumented function, and have the instrumented function branch to a
> > > common trampoline which can load that pointer (and can then branch to
> > > any direct func as necessary).
> > >
> > > The instrumented function looks like:
> > >
> > > # Aligned to 8 bytes
> > > func - 8:
> > > < pointer to ops >
> >
> > stupid question.. so there's ftrace_ops pointer stored for each function at
> > 'func - 8` ? why not store the func's direct trampoline address in there?
>
> Once reason is that today we don't have trampolines for all ops. Since
> branch range limitations can require bouncing through the common ops,
> it's simpler/better to bounce from that to the regular call than to
> bounce from that to a trampoline which makes the regular call.
>
> We *could* consider adding trampolines, but that comes with a jump in
> complexity that we originally tried to avoid, and a potential
> performance hit for regular ftrace calls. IIUC that will require similar
> synchronization to what we have today, so it's not clearly a win
> generally.
>
> I'd like to better understand what the real bottleneck is; AFAICT it's
> the tasks-rcu synchronization, and sharing the hash means that you only
> need to do that once. I think that it should be possible to share that
> synchronization across multiple ops updates with some API changes (e.g.
> something like the batching of text_poke on x86).
yea, so rcu does not seem to be the cause anymore (IIRC that was the
case some time ago) it looks like now the time is spent in the ftrace
internals that iterate and update call sites
the test was loop on attach/detach of fentry program
31.48% test_progs [kernel.kallsyms]
[k] ftrace_replace_code
10.98% test_progs [kernel.kallsyms]
[k] __ftrace_hash_update_ipmodify
6.41% test_progs [kernel.kallsyms]
[k] __ftrace_hash_rec_update
4.69% test_progs [kernel.kallsyms]
[k] ftrace_check_record
4.59% test_progs [kernel.kallsyms]
[k] ftrace_lookup_ip
3.65% swapper [kernel.kallsyms]
[k] acpi_os_read_port
3.40% test_progs [kernel.kallsyms]
[k] srso_alias_return_thunk
2.97% test_progs [kernel.kallsyms]
[k] srso_alias_safe_ret
2.67% test_progs [kernel.kallsyms]
[k] ftrace_rec_iter_record
2.05% test_progs [kernel.kallsyms]
[k] ftrace_test_record
1.83% test_progs [kernel.kallsyms]
[k] ftrace_rec_iter_next
1.76% test_progs [kernel.kallsyms]
[k] smp_call_function_many_cond
1.05% rcu_tasks_kthre [kernel.kallsyms]
[k] rcu_tasks_pertask
0.70% test_progs [kernel.kallsyms]
[k] btf_find_by_name_kind
0.61% swapper [kernel.kallsyms]
[k] srso_alias_safe_ret
0.55% swapper [kernel.kallsyms]
[k] io_idle
so by sharing the hash we do that (iterate and update functions)
just once
jirka
---
31.48% test_progs [kernel.kallsyms]
[k] ftrace_replace_code
|
|--11.54%--ftrace_replace_code
| ftrace_modify_all_code
| |
| |--6.06%--ftrace_shutdown.part.0
| | unregister_ftrace_function
| | unregister_ftrace_direct
| | bpf_trampoline_update
| | bpf_trampoline_unlink_prog
| | bpf_tracing_link_release
| | bpf_link_free
| | bpf_link_release
| | __fput
| | __x64_sys_close
| | do_syscall_64
| | entry_SYSCALL_64_after_hwframe
| | __syscall_cancel_arch_end
| | __syscall_cancel
| | __close
| | fentry_test_common
| | fentry_test
| | test_fentry_test
| | run_one_test
| | main
| | __libc_start_call_main
| | __libc_start_main@@GLIBC_2.34
| | _start
| |
| --5.47%--ftrace_startup
| register_ftrace_function_nolock
| register_ftrace_direct
| bpf_trampoline_update
| __bpf_trampoline_link_prog
| bpf_trampoline_link_prog
| bpf_tracing_prog_attach
| bpf_raw_tp_link_attach
| __sys_bpf
| __x64_sys_bpf
| do_syscall_64
| entry_SYSCALL_64_after_hwframe
| syscall
| skel_raw_tracepoint_open
| fentry_test_lskel__test1__attach
| fentry_test_common
| fentry_test
| test_fentry_test
| run_one_test
| main
| __libc_start_call_main
| __libc_start_main@@GLIBC_2.34
| _start
|
|--8.81%--ftrace_check_record
| ftrace_replace_code
| ftrace_modify_all_code
| |
| |--4.72%--ftrace_shutdown.part.0
| | unregister_ftrace_function
| | unregister_ftrace_direct
| | bpf_trampoline_update
| | bpf_trampoline_unlink_prog
| | bpf_tracing_link_release
| | bpf_link_free
| | bpf_link_release
| | __fput
| | __x64_sys_close
| | do_syscall_64
| | entry_SYSCALL_64_after_hwframe
| | __syscall_cancel_arch_end
| | __syscall_cancel
| | __close
| | fentry_test_common
| | fentry_test
| | test_fentry_test
| | run_one_test
| | main
| | __libc_start_call_main
| | __libc_start_main@@GLIBC_2.34
| | _start
| |
| --4.10%--ftrace_startup
| register_ftrace_function_nolock
| register_ftrace_direct
| bpf_trampoline_update
| __bpf_trampoline_link_prog
| bpf_trampoline_link_prog
| bpf_tracing_prog_attach
| bpf_raw_tp_link_attach
| __sys_bpf
| __x64_sys_bpf
| do_syscall_64
| entry_SYSCALL_64_after_hwframe
| syscall
| skel_raw_tracepoint_open
| fentry_test_lskel__test1__attach
| fentry_test_common
| fentry_test
| test_fentry_test
| run_one_test
| main
| __libc_start_call_main
| __libc_start_main@@GLIBC_2.34
| _start
|
|--3.60%--ftrace_rec_iter_record
| ftrace_replace_code
| ftrace_modify_all_code
| |
| |--1.91%--ftrace_shutdown.part.0
| | unregister_ftrace_function
| | unregister_ftrace_direct
| | bpf_trampoline_update
| | bpf_trampoline_unlink_prog
| | bpf_tracing_link_release
| | bpf_link_free
| | bpf_link_release
| | __fput
| | __x64_sys_close
| | do_syscall_64
| | entry_SYSCALL_64_after_hwframe
| | __syscall_cancel_arch_end
| | __syscall_cancel
| | __close
| | fentry_test_common
| | fentry_test
| | test_fentry_test
| | run_one_test
| | main
| | __libc_start_call_main
| | __libc_start_main@@GLIBC_2.34
| | _start
| |
| --1.69%--ftrace_startup
| register_ftrace_function_nolock
| register_ftrace_direct
| bpf_trampoline_update
| __bpf_trampoline_link_prog
| bpf_trampoline_link_prog
| bpf_tracing_prog_attach
| bpf_raw_tp_link_attach
| __sys_bpf
| __x64_sys_bpf
| do_syscall_64
| entry_SYSCALL_64_after_hwframe
| syscall
| skel_raw_tracepoint_open
| fentry_test_lskel__test1__attach
| fentry_test_common
| fentry_test
| test_fentry_test
| run_one_test
| main
| __libc_start_call_main
| __libc_start_main@@GLIBC_2.34
| _start
|
|--3.50%--ftrace_rec_iter_next
| ftrace_replace_code
| ftrace_modify_all_code
| |
| |--2.08%--ftrace_startup
| | register_ftrace_function_nolock
| | register_ftrace_direct
| | bpf_trampoline_update
| | __bpf_trampoline_link_prog
| | bpf_trampoline_link_prog
| | bpf_tracing_prog_attach
| | bpf_raw_tp_link_attach
| | __sys_bpf
| | __x64_sys_bpf
| | do_syscall_64
| | entry_SYSCALL_64_after_hwframe
| | syscall
| | skel_raw_tracepoint_open
| | fentry_test_lskel__test1__attach
| | fentry_test_common
| | fentry_test
| | test_fentry_test
| | run_one_test
| | main
| | __libc_start_call_main
| | __libc_start_main@@GLIBC_2.34
| | _start
| |
| --1.42%--ftrace_shutdown.part.0
| unregister_ftrace_function
| unregister_ftrace_direct
| bpf_trampoline_update
| bpf_trampoline_unlink_prog
| bpf_tracing_link_release
| bpf_link_free
| bpf_link_release
| __fput
| __x64_sys_close
| do_syscall_64
| entry_SYSCALL_64_after_hwframe
| __syscall_cancel_arch_end
| __syscall_cancel
| __close
| fentry_test_common
| fentry_test
| test_fentry_test
| run_one_test
| main
| __libc_start_call_main
| __libc_start_main@@GLIBC_2.34
| _start
|
|--2.44%--srso_alias_safe_ret
| srso_alias_return_thunk
| ftrace_replace_code
| ftrace_modify_all_code
| |
| |--1.36%--ftrace_shutdown.part.0
| | unregister_ftrace_function
| | unregister_ftrace_direct
| | bpf_trampoline_update
| | bpf_trampoline_unlink_prog
| | bpf_tracing_link_release
| | bpf_link_free
| | bpf_link_release
| | __fput
| | __x64_sys_close
| | do_syscall_64
| | entry_SYSCALL_64_after_hwframe
| | __syscall_cancel_arch_end
| | __syscall_cancel
| | __close
| | fentry_test_common
| | fentry_test
| | test_fentry_test
| | run_one_test
| | main
| | __libc_start_call_main
| | __libc_start_main@@GLIBC_2.34
| | _start
| |
| --1.07%--ftrace_startup
| register_ftrace_function_nolock
| register_ftrace_direct
| bpf_trampoline_update
| __bpf_trampoline_link_prog
| bpf_trampoline_link_prog
| bpf_tracing_prog_attach
| bpf_raw_tp_link_attach
| __sys_bpf
| __x64_sys_bpf
| do_syscall_64
| entry_SYSCALL_64_after_hwframe
| syscall
| skel_raw_tracepoint_open
| fentry_test_lskel__test1__attach
| fentry_test_common
| fentry_test
| test_fentry_test
| run_one_test
| main
| __libc_start_call_main
| __libc_start_main@@GLIBC_2.34
| _start
|
--1.59%--ftrace_test_record
ftrace_replace_code
ftrace_modify_all_code
|
|--0.87%--ftrace_startup
| register_ftrace_function_nolock
| register_ftrace_direct
| bpf_trampoline_update
| __bpf_trampoline_link_prog
| bpf_trampoline_link_prog
| bpf_tracing_prog_attach
| bpf_raw_tp_link_attach
| __sys_bpf
| __x64_sys_bpf
| do_syscall_64
| entry_SYSCALL_64_after_hwframe
| syscall
| skel_raw_tracepoint_open
| fentry_test_lskel__test1__attach
| fentry_test_common
| fentry_test
| test_fentry_test
| run_one_test
| main
| __libc_start_call_main
| __libc_start_main@@GLIBC_2.34
| _start
|
--0.72%--ftrace_shutdown.part.0
unregister_ftrace_function
unregister_ftrace_direct
bpf_trampoline_update
bpf_trampoline_unlink_prog
bpf_tracing_link_release
bpf_link_free
bpf_link_release
__fput
__x64_sys_close
do_syscall_64
entry_SYSCALL_64_after_hwframe
__syscall_cancel_arch_end
__syscall_cancel
__close
fentry_test_common
fentry_test
test_fentry_test
run_one_test
main
__libc_start_call_main
__libc_start_main@@GLIBC_2.34
_start
10.98% test_progs [kernel.kallsyms]
[k] __ftrace_hash_update_ipmodify
|
|--7.90%--__ftrace_hash_update_ipmodify
| |
| |--4.27%--ftrace_shutdown.part.0
| | unregister_ftrace_function
| | unregister_ftrace_direct
| | bpf_trampoline_update
| | bpf_trampoline_unlink_prog
| | bpf_tracing_link_release
| | bpf_link_free
| | bpf_link_release
| | __fput
| | __x64_sys_close
| | do_syscall_64
| | entry_SYSCALL_64_after_hwframe
| | __syscall_cancel_arch_end
| | __syscall_cancel
| | __close
| | fentry_test_common
| | fentry_test
| | test_fentry_test
| | run_one_test
| | main
| | __libc_start_call_main
| | __libc_start_main@@GLIBC_2.34
| | _start
| |
| --3.63%--ftrace_startup
| register_ftrace_function_nolock
| register_ftrace_direct
| bpf_trampoline_update
| __bpf_trampoline_link_prog
| bpf_trampoline_link_prog
| bpf_tracing_prog_attach
| bpf_raw_tp_link_attach
| __sys_bpf
| __x64_sys_bpf
| do_syscall_64
| entry_SYSCALL_64_after_hwframe
| syscall
| skel_raw_tracepoint_open
| fentry_test_lskel__test1__attach
| fentry_test_common
| fentry_test
| test_fentry_test
| run_one_test
| main
| __libc_start_call_main
| __libc_start_main@@GLIBC_2.34
| _start
|
--3.06%--ftrace_lookup_ip
__ftrace_hash_update_ipmodify
|
|--1.92%--ftrace_startup
| register_ftrace_function_nolock
| register_ftrace_direct
| bpf_trampoline_update
| __bpf_trampoline_link_prog
| bpf_trampoline_link_prog
| bpf_tracing_prog_attach
| bpf_raw_tp_link_attach
| __sys_bpf
| __x64_sys_bpf
| do_syscall_64
| entry_SYSCALL_64_after_hwframe
| syscall
| skel_raw_tracepoint_open
| fentry_test_lskel__test1__attach
| fentry_test_common
| fentry_test
| test_fentry_test
| run_one_test
| main
| __libc_start_call_main
| __libc_start_main@@GLIBC_2.34
| _start
|
--1.14%--ftrace_shutdown.part.0
unregister_ftrace_function
unregister_ftrace_direct
bpf_trampoline_update
bpf_trampoline_unlink_prog
bpf_tracing_link_release
bpf_link_free
bpf_link_release
__fput
__x64_sys_close
do_syscall_64
entry_SYSCALL_64_after_hwframe
__syscall_cancel_arch_end
__syscall_cancel
__close
fentry_test_common
fentry_test
test_fentry_test
run_one_test
main
__libc_start_call_main
__libc_start_main@@GLIBC_2.34
_start
6.41% test_progs [kernel.kallsyms]
[k] __ftrace_hash_rec_update
|
|--3.37%--__ftrace_hash_rec_update
| |
| |--1.90%--ftrace_startup
| | register_ftrace_function_nolock
| | register_ftrace_direct
| | bpf_trampoline_update
| | __bpf_trampoline_link_prog
| | bpf_trampoline_link_prog
| | bpf_tracing_prog_attach
| | bpf_raw_tp_link_attach
| | __sys_bpf
| | __x64_sys_bpf
| | do_syscall_64
| | entry_SYSCALL_64_after_hwframe
| | syscall
| | skel_raw_tracepoint_open
| | fentry_test_lskel__test1__attach
| | fentry_test_common
| | fentry_test
| | test_fentry_test
| | run_one_test
| | main
| | __libc_start_call_main
| | __libc_start_main@@GLIBC_2.34
| | _start
| |
| --1.47%--ftrace_shutdown.part.0
| unregister_ftrace_function
| unregister_ftrace_direct
| bpf_trampoline_update
| bpf_trampoline_unlink_prog
| bpf_tracing_link_release
| bpf_link_free
| bpf_link_release
| __fput
| __x64_sys_close
| do_syscall_64
| entry_SYSCALL_64_after_hwframe
| __syscall_cancel_arch_end
| __syscall_cancel
| __close
| fentry_test_common
| fentry_test
| test_fentry_test
| run_one_test
| main
| __libc_start_call_main
| __libc_start_main@@GLIBC_2.34
| _start
|
|--2.16%--ftrace_lookup_ip
| __ftrace_hash_rec_update
| |
| |--1.16%--ftrace_shutdown.part.0
| | unregister_ftrace_function
| | unregister_ftrace_direct
| | bpf_trampoline_update
| | bpf_trampoline_unlink_prog
| | bpf_tracing_link_release
| | bpf_link_free
| | bpf_link_release
| | __fput
| | __x64_sys_close
| | do_syscall_64
| | entry_SYSCALL_64_after_hwframe
| | __syscall_cancel_arch_end
| | __syscall_cancel
| | __close
| | fentry_test_common
| | fentry_test
| | test_fentry_test
| | run_one_test
| | main
| | __libc_start_call_main
| | __libc_start_main@@GLIBC_2.34
| | _start
| |
| --0.99%--ftrace_startup
| register_ftrace_function_nolock
| register_ftrace_direct
| bpf_trampoline_update
| __bpf_trampoline_link_prog
| bpf_trampoline_link_prog
| bpf_tracing_prog_attach
| bpf_raw_tp_link_attach
| __sys_bpf
| __x64_sys_bpf
| do_syscall_64
| entry_SYSCALL_64_after_hwframe
| syscall
| skel_raw_tracepoint_open
| fentry_test_lskel__test1__attach
| fentry_test_common
| fentry_test
| test_fentry_test
| run_one_test
| main
| __libc_start_call_main
| __libc_start_main@@GLIBC_2.34
| _start
|
--0.88%--srso_alias_safe_ret
|
--0.79%--__ftrace_hash_rec_update
|
--0.52%--ftrace_shutdown.part.0
unregister_ftrace_function
unregister_ftrace_direct
bpf_trampoline_update
bpf_trampoline_unlink_prog
bpf_tracing_link_release
bpf_link_free
bpf_link_release
__fput
__x64_sys_close
do_syscall_64
entry_SYSCALL_64_after_hwframe
__syscall_cancel_arch_end
__syscall_cancel
__close
fentry_test_common
fentry_test
test_fentry_test
run_one_test
main
__libc_start_call_main
__libc_start_main@@GLIBC_2.34
_start
4.69% test_progs [kernel.kallsyms]
[k] ftrace_check_record
|
|--2.04%--ftrace_check_record
| ftrace_replace_code
| ftrace_modify_all_code
| |
| |--1.06%--ftrace_startup
| | register_ftrace_function_nolock
| | register_ftrace_direct
| | bpf_trampoline_update
| | __bpf_trampoline_link_prog
| | bpf_trampoline_link_prog
| | bpf_tracing_prog_attach
| | bpf_raw_tp_link_attach
| | __sys_bpf
| | __x64_sys_bpf
| | do_syscall_64
| | entry_SYSCALL_64_after_hwframe
| | syscall
| | skel_raw_tracepoint_open
| | fentry_test_lskel__test1__attach
| | fentry_test_common
| | fentry_test
| | test_fentry_test
| | run_one_test
| | main
| | __libc_start_call_main
| | __libc_start_main@@GLIBC_2.34
| | _start
| |
| --0.98%--ftrace_shutdown.part.0
| unregister_ftrace_function
| unregister_ftrace_direct
| bpf_trampoline_update
| bpf_trampoline_unlink_prog
| bpf_tracing_link_release
| bpf_link_free
| bpf_link_release
| __fput
| __x64_sys_close
| do_syscall_64
| entry_SYSCALL_64_after_hwframe
| __syscall_cancel_arch_end
| __syscall_cancel
| __close
| fentry_test_common
| fentry_test
| test_fentry_test
| run_one_test
| main
| __libc_start_call_main
| __libc_start_main@@GLIBC_2.34
| _start
|
--1.28%--ftrace_replace_code
ftrace_modify_all_code
|
--0.81%--ftrace_startup
register_ftrace_function_nolock
register_ftrace_direct
bpf_trampoline_update
__bpf_trampoline_link_prog
bpf_trampoline_link_prog
bpf_tracing_prog_attach
bpf_raw_tp_link_attach
__sys_bpf
__x64_sys_bpf
do_syscall_64
entry_SYSCALL_64_after_hwframe
syscall
skel_raw_tracepoint_open
fentry_test_lskel__test1__attach
fentry_test_common
fentry_test
test_fentry_test
run_one_test
main
__libc_start_call_main
__libc_start_main@@GLIBC_2.34
_start
4.59% test_progs [kernel.kallsyms]
[k] ftrace_lookup_ip
|
|--1.99%--__ftrace_hash_update_ipmodify
| |
| |--1.03%--ftrace_shutdown.part.0
| | unregister_ftrace_function
| | unregister_ftrace_direct
| | bpf_trampoline_update
| | bpf_trampoline_unlink_prog
| | bpf_tracing_link_release
| | bpf_link_free
| | bpf_link_release
| | __fput
| | __x64_sys_close
| | do_syscall_64
| | entry_SYSCALL_64_after_hwframe
| | __syscall_cancel_arch_end
| | __syscall_cancel
| | __close
| | fentry_test_common
| | fentry_test
| | test_fentry_test
| | run_one_test
| | main
| | __libc_start_call_main
| | __libc_start_main@@GLIBC_2.34
| | _start
| |
| --0.96%--ftrace_startup
| register_ftrace_function_nolock
| register_ftrace_direct
| bpf_trampoline_update
| __bpf_trampoline_link_prog
| bpf_trampoline_link_prog
| bpf_tracing_prog_attach
| bpf_raw_tp_link_attach
| __sys_bpf
| __x64_sys_bpf
| do_syscall_64
| entry_SYSCALL_64_after_hwframe
| syscall
| skel_raw_tracepoint_open
| fentry_test_lskel__test1__attach
| fentry_test_common
| fentry_test
| test_fentry_test
| run_one_test
| main
| __libc_start_call_main
| __libc_start_main@@GLIBC_2.34
| _start
|
|--1.67%--ftrace_lookup_ip
| |
| --1.19%--__ftrace_hash_update_ipmodify
| |
| |--0.60%--ftrace_shutdown.part.0
| | unregister_ftrace_function
| | unregister_ftrace_direct
| | bpf_trampoline_update
| | bpf_trampoline_unlink_prog
| | bpf_tracing_link_release
| | bpf_link_free
| | bpf_link_release
| | __fput
| | __x64_sys_close
| | do_syscall_64
| | entry_SYSCALL_64_after_hwframe
| | __syscall_cancel_arch_end
| | __syscall_cancel
| | __close
| | fentry_test_common
| | fentry_test
| | test_fentry_test
| | run_one_test
| | main
| | __libc_start_call_main
| | __libc_start_main@@GLIBC_2.34
| | _start
| |
| --0.59%--ftrace_startup
| register_ftrace_function_nolock
| register_ftrace_direct
| bpf_trampoline_update
| __bpf_trampoline_link_prog
| bpf_trampoline_link_prog
| bpf_tracing_prog_attach
| bpf_raw_tp_link_attach
| __sys_bpf
| __x64_sys_bpf
| do_syscall_64
| entry_SYSCALL_64_after_hwframe
| syscall
| skel_raw_tracepoint_open
| fentry_test_lskel__test1__attach
| fentry_test_common
| fentry_test
| test_fentry_test
| run_one_test
| main
| __libc_start_call_main
| __libc_start_main@@GLIBC_2.34
| _start
|
--0.81%--__ftrace_hash_rec_update
3.65% swapper [kernel.kallsyms]
[k] acpi_os_read_port
|
|--1.03%--acpi_os_read_port
| acpi_hw_read_port
| acpi_hw_read
| acpi_hw_register_read
| acpi_read_bit_register
| acpi_idle_enter_bm
| cpuidle_enter_state
| cpuidle_enter
| do_idle
| cpu_startup_entry
| |
| --0.97%--start_secondary
| common_startup_64
|
|--0.82%--srso_alias_safe_ret
|
--0.74%--acpi_hw_read
acpi_hw_register_read
acpi_read_bit_register
acpi_idle_enter_bm
cpuidle_enter_state
cpuidle_enter
do_idle
cpu_startup_entry
|
--0.74%--start_secondary
common_startup_64
3.40% test_progs [kernel.kallsyms]
[k] srso_alias_return_thunk
|
|--0.85%--ftrace_replace_code
| ftrace_modify_all_code
| |
| --0.51%--ftrace_startup
| register_ftrace_function_nolock
| register_ftrace_direct
| bpf_trampoline_update
| __bpf_trampoline_link_prog
| bpf_trampoline_link_prog
| bpf_tracing_prog_attach
| bpf_raw_tp_link_attach
| __sys_bpf
| __x64_sys_bpf
| do_syscall_64
| entry_SYSCALL_64_after_hwframe
| syscall
| skel_raw_tracepoint_open
| fentry_test_lskel__test1__attach
| fentry_test_common
| fentry_test
| test_fentry_test
| run_one_test
| main
| __libc_start_call_main
| __libc_start_main@@GLIBC_2.34
| _start
|
--0.64%--ftrace_check_record
ftrace_replace_code
ftrace_modify_all_code
2.97% test_progs [kernel.kallsyms]
[k] srso_alias_safe_ret
|
|--0.73%--ftrace_check_record
| ftrace_replace_code
| ftrace_modify_all_code
|
--0.69%--ftrace_replace_code
ftrace_modify_all_code
2.67% test_progs [kernel.kallsyms]
[k] ftrace_rec_iter_record
|
|--1.19%--ftrace_replace_code
| ftrace_modify_all_code
| |
| |--0.68%--ftrace_startup
| | register_ftrace_function_nolock
| | register_ftrace_direct
| | bpf_trampoline_update
| | __bpf_trampoline_link_prog
| | bpf_trampoline_link_prog
| | bpf_tracing_prog_attach
| | bpf_raw_tp_link_attach
| | __sys_bpf
| | __x64_sys_bpf
| | do_syscall_64
| | entry_SYSCALL_64_after_hwframe
| | syscall
| | skel_raw_tracepoint_open
| | fentry_test_lskel__test1__attach
| | fentry_test_common
| | fentry_test
| | test_fentry_test
| | run_one_test
| | main
| | __libc_start_call_main
| | __libc_start_main@@GLIBC_2.34
| | _start
| |
| --0.51%--ftrace_shutdown.part.0
| unregister_ftrace_function
| unregister_ftrace_direct
| bpf_trampoline_update
| bpf_trampoline_unlink_prog
| bpf_tracing_link_release
| bpf_link_free
| bpf_link_release
| __fput
| __x64_sys_close
| do_syscall_64
| entry_SYSCALL_64_after_hwframe
| __syscall_cancel_arch_end
| __syscall_cancel
| __close
| fentry_test_common
| fentry_test
| test_fentry_test
| run_one_test
| main
| __libc_start_call_main
| __libc_start_main@@GLIBC_2.34
| _start
|
--0.69%--ftrace_check_record
ftrace_replace_code
ftrace_modify_all_code
2.05% test_progs [kernel.kallsyms]
[k] ftrace_test_record
|
--0.79%--ftrace_replace_code
ftrace_modify_all_code
1.83% test_progs [kernel.kallsyms]
[k] ftrace_rec_iter_next
|
--0.87%--ftrace_replace_code
ftrace_modify_all_code
|
--0.51%--ftrace_startup
register_ftrace_function_nolock
register_ftrace_direct
bpf_trampoline_update
__bpf_trampoline_link_prog
bpf_trampoline_link_prog
bpf_tracing_prog_attach
bpf_raw_tp_link_attach
__sys_bpf
__x64_sys_bpf
do_syscall_64
entry_SYSCALL_64_after_hwframe
syscall
skel_raw_tracepoint_open
fentry_test_lskel__test1__attach
fentry_test_common
fentry_test
test_fentry_test
run_one_test
main
__libc_start_call_main
__libc_start_main@@GLIBC_2.34
_start
1.76% test_progs [kernel.kallsyms]
[k] smp_call_function_many_cond
|
--1.73%--smp_call_function_many_cond
on_each_cpu_cond_mask
|
--1.57%--smp_text_poke_batch_finish
|
--1.55%--ftrace_modify_all_code
|
|--0.91%--ftrace_shutdown.part.0
|
unregister_ftrace_function
| unregister_ftrace_direct
| bpf_trampoline_update
|
bpf_trampoline_unlink_prog
| bpf_tracing_link_release
| bpf_link_free
| bpf_link_release
| __fput
| __x64_sys_close
| do_syscall_64
|
entry_SYSCALL_64_after_hwframe
|
__syscall_cancel_arch_end
| __syscall_cancel
| __close
| fentry_test_common
| fentry_test
| test_fentry_test
| run_one_test
| main
| __libc_start_call_main
|
__libc_start_main@@GLIBC_2.34
| _start
|
--0.64%--ftrace_startup
register_ftrace_function_nolock
register_ftrace_direct
bpf_trampoline_update
__bpf_trampoline_link_prog
bpf_trampoline_link_prog
bpf_tracing_prog_attach
bpf_raw_tp_link_attach
__sys_bpf
__x64_sys_bpf
do_syscall_64
entry_SYSCALL_64_after_hwframe
syscall
skel_raw_tracepoint_open
fentry_test_lskel__test1__attach
fentry_test_common
fentry_test
test_fentry_test
run_one_test
main
__libc_start_call_main
__libc_start_main@@GLIBC_2.34
_start
1.05% rcu_tasks_kthre [kernel.kallsyms]
[k] rcu_tasks_pertask
|
--0.65%--rcu_tasks_wait_gp
rcu_tasks_one_gp
rcu_tasks_kthread
kthread
ret_from_fork
ret_from_fork_asm
0.70% test_progs [kernel.kallsyms]
[k] btf_find_by_name_kind
|
--0.59%--btf_find_by_name_kind
