rcu_read_lock_tasks_trace(9)

🌸 NAME 🌸

rcu_read_lock_tasks_trace — mark beginning of RCU-trace read-side critical section. ✨

Okay bestie, this is the manual page for rcu_read_lock_tasks_trace(9) from the Kernel API Manual, and yes we're getting into the RCU-trace read-side critical-section lore. 💅

✨ SYNOPSIS ✨

struct srcu_ctr __percpu * rcu_read_lock_tasks_trace (void );

🎀 ARGUMENTS 🎀

• void — no arguments, bestie. Literally none. 🫶

💖 DESCRIPTION 💖

When synchronize_rcu_tasks_trace is invoked by one task, then that task is guaranteed to block until all other tasks exit their read-side critical sections. No cap. 😭

Similarly, if call_rcu_trace is invoked on one task while other tasks are within RCU read-side critical sections, invocation of the corresponding RCU callback is deferred until after all the other tasks exit their critical sections. The callback is lowkey waiting its turn, periodt. 💀

For more details, please see the documentation for srcu_read_lock_fast. 📚

For a description of how implicit RCU readers provide the needed ordering for architectures defining the ARCH_WANTS_NO_INSTR Kconfig option (and thus promising never to trace code where RCU is not watching), please see the __srcu_read_lock_fast (non-kerneldoc) header comment. 👀 Otherwise, the smp_mb below provided the needed ordering. 🧚

🌈 SEE ALSO 🌈

• Kernel file ./include/linux/rcupdate_trace.h
• rcu_read_unlock_tasks_trace(9)
• rcu_read_lock_trace(9)
• rcu_read_unlock_trace(9)
• call_rcu_tasks_trace(9)
• synchronize_rcu_tasks_trace(9)
• rcu_barrier_tasks_trace(9)
• rcu_tasks_trace_expedite_current(9)

mwah 💋 byeee, this was rcu_read_lock_tasks_trace(9) from the Kernel API Manual — source/version: ./include/linux, dated October 2026. 🎀✨