ftrace_startup_subops(9)

✨ ftrace_startup_subops 💅

okay so bestie, welcome to the Kernel API Manual 🎀 this one's ftrace_startup_subops(9) and it's lowkey the glow-up button for your tracing ops. sit down, grab a boba, let's go 🧋

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🌸 NAME 🌸

ftrace_startup_subops — enable tracing for subops of an ops ✨

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🦋 SYNOPSIS 🦋

int ftrace_startup_subops (struct ftrace_ops *ops , struct ftrace_ops
*subops , int command );

that's the whole signature, no cap. returns an int, takes three things 💅

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💖 ARGUMENTS 💖

• ops — the manager ops 👑 and here's the vibe: it's used to pick all the functions of its subops. it's giving team captain energy.
• subops — a new ops that you're adding to ops 🫶 fresh recruit, welcome to the group chat.
• command — extra commands you can use to enable tracing ⭐ little extra instructions, iykyk.

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🌈 DESCRIPTION 🌈

so the tea ☕ — ops here is a manager ops that's holding the filter including all the functions that its list of subops are tracing. literally the main character of the function list.

when you add a new subops, the functions of subops get added to ops. that's it, that's the whole plot 🍓 the family grows, the filter grows, the tracing slays. periodt 💅

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👑 SEE ALSO 👑

the kernel file ./kernel/trace/ftrace.c and like, the entire extended universe of friends 🌌 — every single one, no skipping:

• ftrace_lookup_ip(9)
• ftrace_free_filter(9)
• ftrace_hash_move(9)
• ftrace_location_range(9)
• ftrace_location(9)
• ftrace_text_reserved(9)
• ftrace_bug(9)
• ftrace_update_record(9)
• ftrace_test_record(9)
• ftrace_get_addr_new(9)
• ftrace_get_addr_curr(9)
• ftrace_rec_iter_start(9)
• ftrace_rec_iter_next(9)
• ftrace_rec_iter_record(9)
• ftrace_run_stop_machine(9)
• arch_ftrace_update_code(9)
• ftrace_shutdown_subops(9)
• ftrace_regex_open(9)
• allocate_ftrace_func_mapper(9)
• ftrace_func_mapper_find_ip(9)
• ftrace_func_mapper_add_ip(9)
• ftrace_func_mapper_remove_ip(9)
• free_ftrace_func_mapper(9)
• register_ftrace_direct(9)
• unregister_ftrace_direct(9)
• modify_ftrace_direct_nolock(9)
• modify_ftrace_direct(9)
• hash_add(9)
• update_ftrace_direct_add(9)
• hash_sub(9)
• update_ftrace_direct_del(9)
• update_ftrace_direct_mod(9)
• ftrace_set_filter_ip(9)
• ftrace_set_filter_ips(9)
• ftrace_ops_set_global_filter(9)
• ftrace_set_filter(9)
• ftrace_set_notrace(9)
• ftrace_set_global_filter(9)
• ftrace_set_global_notrace(9)
• ftrace_ops_get_func(9)
• ftrace_kill(9)
• ftrace_is_dead(9)
• register_ftrace_function(9)
• unregister_ftrace_function(9)
• ftrace_lookup_symbols(9)

like I said. the whole universe 🌈🔭

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💀 real talk: this page is the Kernel API Manual, living under ./kernel/trace, dated October 2026, and it's filed as ftrace_startup_subops(9). screenshot it, cite it, put it on your vision board 🙈

okay bye bestie, go add those subops, ily 🫶💜