Le Fri, Sep 11, 2026 at 02:08:41PM +0000, Josef Bacik a écrit : > A trampoline's own rcu_tramp_nesting increment and decrement live inside > the trampoline, so there is a window of a few instructions on entry and > exit where the count is zero while the CPU is executing trampoline text > (or text on the way into one, such as a static ftrace stub holding a > direct-call target). In that window the task has not called out, so it > can only be preempted from an interrupt, and the interrupted instruction > pointer identifies where it is.
I haven't read the whole patchset yet but what happens if the count is zero on trampoline exit but the trampoline isn't finished yet and RCU tasks does a fully quiescent scan of all tasks during that short window? Isn't that ending with a too short grace period? Thanks. -- Frederic Weisbecker SUSE Labs
