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| author |   Paul E. McKenney <paulmck@kernel.org> | 2022-03-11 10:10:35 -0800 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@kernel.org> | 2022-04-20 16:51:10 -0700 |
| commit | 80d530b47da41642fab317a9485d58dfbe1e8896 (patch) | |
| tree | 5bb10867764c11b195779a11ee844f8c30977974 /kernel/rcu/tree_stall.h | |
| parent | rcu: Add comments to final rcu_gp_cleanup() "if" statement (diff) | |
| download | linux-dev-80d530b47da41642fab317a9485d58dfbe1e8896.tar.xz linux-dev-80d530b47da41642fab317a9485d58dfbe1e8896.zip | |
rcu: Print number of online CPUs in RCU CPU stall-warning messages
RCU's synchronous grace periods act quite differently when there is
only one online CPU, especially in the no-op case in kernels built with
CONFIG_PREEMPTION=n. This change in behavior can be important debugging
information, so this commit adds the number of online CPUs to the RCU
CPU stall warning messages.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Diffstat (limited to 'kernel/rcu/tree_stall.h')
| -rw-r--r-- | kernel/rcu/tree_stall.h | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/kernel/rcu/tree_stall.h b/kernel/rcu/tree_stall.h index 0c5d8516516a..268dd79c58e7 100644 --- a/kernel/rcu/tree_stall.h +++ b/kernel/rcu/tree_stall.h @@ -565,9 +565,9 @@ static void print_other_cpu_stall(unsigned long gp_seq, unsigned long gps) for_each_possible_cpu(cpu) totqlen += rcu_get_n_cbs_cpu(cpu); - pr_cont("\t(detected by %d, t=%ld jiffies, g=%ld, q=%lu)\n", + pr_cont("\t(detected by %d, t=%ld jiffies, g=%ld, q=%lu ncpus=%d)\n", smp_processor_id(), (long)(jiffies - gps), - (long)rcu_seq_current(&rcu_state.gp_seq), totqlen); + (long)rcu_seq_current(&rcu_state.gp_seq), totqlen, rcu_state.n_online_cpus); if (ndetected) { rcu_dump_cpu_stacks(); @@ -626,9 +626,9 @@ static void print_cpu_stall(unsigned long gps) raw_spin_unlock_irqrestore_rcu_node(rdp->mynode, flags); for_each_possible_cpu(cpu) totqlen += rcu_get_n_cbs_cpu(cpu); - pr_cont("\t(t=%lu jiffies g=%ld q=%lu)\n", + pr_cont("\t(t=%lu jiffies g=%ld q=%lu ncpus=%d)\n", jiffies - gps, - (long)rcu_seq_current(&rcu_state.gp_seq), totqlen); + (long)rcu_seq_current(&rcu_state.gp_seq), totqlen, rcu_state.n_online_cpus); rcu_check_gp_kthread_expired_fqs_timer(); rcu_check_gp_kthread_starvation(); |