Hi Linus, The following changes since commit 6613476e225e090cc9aad49be7fa504e290dd33d: Linux 6.8-rc1 (2024-01-21 14:11:32 -0800) are available in the Git repository at: https://github.com/neeraju/linux.git tags/urgent-rcu.2024.01.24a for you to fetch changes up to e787644caf7628ad3269c1fbd321c3255cf51710: rcu: Defer RCU kthreads wakeup when CPU is dying (2024-01-24 22:46:17 +0530) ---------------------------------------------------------------- Urgent RCU pull request for v6.8 This commit fixes RCU grace period stalls, which are observed when an outgoing CPU's quiescent state reporting results in wakeup of one of the grace period kthreads, to complete the grace period. If those kthreads have SCHED_FIFO policy, the wake up can indirectly arm the RT bandwith timer to the local offline CPU. Earlier migration of the hrtimers from the CPU introduced in commit 5c0930ccaad5 ("hrtimers: Push pending hrtimers away from outgoing CPU earlier") results in this timer getting ignored. If the RCU grace period kthreads are waiting for RT bandwidth to be available, they may never be actually scheduled, resulting in RCU stall warnings. ---------------------------------------------------------------- Frederic Weisbecker (1): rcu: Defer RCU kthreads wakeup when CPU is dying kernel/rcu/tree.c | 34 +++++++++++++++++++++++++++++++++- kernel/rcu/tree_exp.h | 3 +-- 2 files changed, 34 insertions(+), 3 deletions(-)
