start_poll_synchronize_rcu(9)

📦 version 7.3.1, in nixpkgs unstable

💅 start_poll_synchronize_rcu(9) — the Kernel API Manual glow-up

okay bestie, welcome to the Kernel API Manual, section 9, and today's main character is start_poll_synchronize_rcu 🎀 she's a little function with a big job: she takes a snapshot and kicks off an RCU grace period. periodt.

✨ NAME ✨

start_poll_synchronize_rcu — snapshot and start RCU grace period 🫶

🌸 SYNOPSIS 🌸

unsigned long start_poll_synchronize_rcu (void );

like, that's the whole signature. yes the space before the ) is supposed to be there. no we're not fixing it. it's iconic 💅

🦋 ARGUMENTS 🦋

  • void — no arguments. zero. nada. she takes nothing and she gives you a cookie. queen behavior honestly 👑

🔥 DESCRIPTION 🔥

so here's the vibe: start_poll_synchronize_rcu returns a cookie 🍪 — and that cookie gets handed off to a later call to cond_synchronize_rcu or poll_state_synchronize_rcu, which use it to figure out whether or not a full grace period has elapsed in the meantime. iykyk.

and if the grace period you need is not already slated to start, she notifies the RCU core that said grace period is needed. like she's texting the group chat "hey we need this, it's happening" 📲✨

👑 SEE ALSO 👑

all the siblings and cousins, no cap. kernel file ./kernel/rcu/tree.c, and then:

the whole friend group fr fr 🌈

aaaand that's the page!! mwah 💖 source lives at ./kernel/rcu, dated October 2026, and it's filed under start_poll_synchronize_rcu(9) — ok bye bestie, go take a snapshot, slay 🧚‍♀️⭐

📦 where this page comes from