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| author |   Paul E. McKenney <paulmck@kernel.org> | 2022-06-01 21:26:57 -0700 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@kernel.org> | 2022-06-21 15:49:38 -0700 |
| commit | ffcc21a315e1ebafad51b318e8ac0cb884df0cdc (patch) | |
| tree | 26ef94faf472c023ec5c5911b54811f03331ab51 | |
| parent | rcu-tasks: Stop RCU Tasks Trace from scanning full tasks list (diff) | |
| download | linux-dev-ffcc21a315e1ebafad51b318e8ac0cb884df0cdc.tar.xz linux-dev-ffcc21a315e1ebafad51b318e8ac0cb884df0cdc.zip | |
rcu-tasks: Maintain a count of tasks blocking RCU Tasks Trace grace period
This commit maintains a new n_trc_holdouts counter that tracks the number
of tasks blocking the RCU Tasks grace period. This counter is useful
for debugging, and its value has been added to a diagostic message.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Cc: Neeraj Upadhyay <quic_neeraju@quicinc.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Andrii Nakryiko <andrii@kernel.org>
Cc: Martin KaFai Lau <kafai@fb.com>
Cc: KP Singh <kpsingh@kernel.org>
| -rw-r--r-- | kernel/rcu/tasks.h | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/kernel/rcu/tasks.h b/kernel/rcu/tasks.h index fe0552086ccf..9d7d6fd4b8a7 100644 --- a/kernel/rcu/tasks.h +++ b/kernel/rcu/tasks.h @@ -1206,6 +1206,7 @@ static DEFINE_PER_CPU(bool, trc_ipi_to_cpu); static unsigned long n_heavy_reader_attempts; static unsigned long n_heavy_reader_updates; static unsigned long n_heavy_reader_ofl_updates; +static unsigned long n_trc_holdouts; void call_rcu_tasks_trace(struct rcu_head *rhp, rcu_callback_t func); DEFINE_RCU_TASKS(rcu_tasks_trace, rcu_tasks_wait_gp, call_rcu_tasks_trace, @@ -1299,6 +1300,7 @@ static void trc_add_holdout(struct task_struct *t, struct list_head *bhp) if (list_empty(&t->trc_holdout_list)) { get_task_struct(t); list_add(&t->trc_holdout_list, bhp); + n_trc_holdouts++; } } @@ -1308,6 +1310,7 @@ static void trc_del_holdout(struct task_struct *t) if (!list_empty(&t->trc_holdout_list)) { list_del_init(&t->trc_holdout_list); put_task_struct(t); + n_trc_holdouts--; } } @@ -1760,7 +1763,8 @@ void show_rcu_tasks_trace_gp_kthread(void) { char buf[64]; - sprintf(buf, "h:%lu/%lu/%lu", + sprintf(buf, "N%lu h:%lu/%lu/%lu", + data_race(n_trc_holdouts), data_race(n_heavy_reader_ofl_updates), data_race(n_heavy_reader_updates), data_race(n_heavy_reader_attempts)); |