From: paulmck@kernel.org
To: rcu@vger.kernel.org
Cc: linux-kernel@vger.kernel.org, kernel-team@fb.com,
mingo@kernel.org, jiangshanlai@gmail.com, dipankar@in.ibm.com,
akpm@linux-foundation.org, mathieu.desnoyers@efficios.com,
josh@joshtriplett.org, tglx@linutronix.de, peterz@infradead.org,
rostedt@goodmis.org, dhowells@redhat.com, edumazet@google.com,
fweisbec@gmail.com, oleg@redhat.com, joel@joelfernandes.org,
"Paul E. McKenney" <paulmck@kernel.org>
Subject: [PATCH tip/core/rcu 04/26] rcu: Add callbacks-invoked counters
Date: Mon, 22 Jun 2020 17:21:25 -0700 [thread overview]
Message-ID: <20200623002147.25750-4-paulmck@kernel.org> (raw)
In-Reply-To: <20200623002128.GA25456@paulmck-ThinkPad-P72>
From: "Paul E. McKenney" <paulmck@kernel.org>
This commit adds a count of the callbacks invoked to the per-CPU rcu_data
structure. This count is printed by the show_rcu_gp_kthreads() that
is invoked by rcutorture and the RCU CPU stall-warning code. It is also
intended for use by drgn.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
---
kernel/rcu/tree.c | 1 +
kernel/rcu/tree.h | 1 +
kernel/rcu/tree_stall.h | 3 +++
3 files changed, 5 insertions(+)
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index 9caaeee..db17ffe 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -2425,6 +2425,7 @@ static void rcu_do_batch(struct rcu_data *rdp)
local_irq_save(flags);
rcu_nocb_lock(rdp);
count = -rcl.len;
+ rdp->n_cbs_invoked += count;
trace_rcu_batch_end(rcu_state.name, count, !!rcl.head, need_resched(),
is_idle_task(current), rcu_is_callbacks_kthread());
diff --git a/kernel/rcu/tree.h b/kernel/rcu/tree.h
index 43991a4..9c6f734 100644
--- a/kernel/rcu/tree.h
+++ b/kernel/rcu/tree.h
@@ -171,6 +171,7 @@ struct rcu_data {
/* different grace periods. */
long qlen_last_fqs_check;
/* qlen at last check for QS forcing */
+ unsigned long n_cbs_invoked; /* # callbacks invoked since boot. */
unsigned long n_force_qs_snap;
/* did other CPU force QS recently? */
long blimit; /* Upper limit on a processed batch */
diff --git a/kernel/rcu/tree_stall.h b/kernel/rcu/tree_stall.h
index 54a6dba..2768ce6 100644
--- a/kernel/rcu/tree_stall.h
+++ b/kernel/rcu/tree_stall.h
@@ -649,6 +649,7 @@ static void check_cpu_stall(struct rcu_data *rdp)
*/
void show_rcu_gp_kthreads(void)
{
+ unsigned long cbs = 0;
int cpu;
unsigned long j;
unsigned long ja;
@@ -690,9 +691,11 @@ void show_rcu_gp_kthreads(void)
}
for_each_possible_cpu(cpu) {
rdp = per_cpu_ptr(&rcu_data, cpu);
+ cbs += data_race(rdp->n_cbs_invoked);
if (rcu_segcblist_is_offloaded(&rdp->cblist))
show_rcu_nocb_state(rdp);
}
+ pr_info("RCU callbacks invoked since boot: %lu\n", cbs);
show_rcu_tasks_gp_kthreads();
}
EXPORT_SYMBOL_GPL(show_rcu_gp_kthreads);
--
2.9.5
next prev parent reply other threads:[~2020-06-23 0:23 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-23 0:21 [PATCH tip/core/rcu 0/26] Miscellaneous fixes for v5.9 Paul E. McKenney
2020-06-23 0:21 ` [PATCH tip/core/rcu 01/26] rcu: Initialize and destroy rcu_synchronize only when necessary paulmck
2020-06-23 0:21 ` [PATCH tip/core/rcu 02/26] mm/mmap.c: Add cond_resched() for exit_mmap() CPU stalls paulmck
2020-06-23 0:47 ` Shakeel Butt
2020-06-23 0:57 ` Paul E. McKenney
2020-06-23 19:34 ` Joel Fernandes
2020-06-23 20:55 ` Paul E. McKenney
2020-06-23 21:01 ` Joel Fernandes
2020-06-23 0:21 ` [PATCH tip/core/rcu 03/26] rcu: Simplify the calculation of rcu_state.ncpus paulmck
2020-06-23 0:21 ` paulmck [this message]
2020-06-23 0:21 ` [PATCH tip/core/rcu 05/26] rcu: Add comment documenting rcu_callback_map's purpose paulmck
2020-06-23 0:21 ` [PATCH tip/core/rcu 06/26] trace: events: rcu: Change description of rcu_dyntick trace event paulmck
2020-06-23 0:21 ` [PATCH tip/core/rcu 07/26] rcu: Grace-period-kthread related sleeps to idle priority paulmck
2020-06-23 0:21 ` [PATCH tip/core/rcu 08/26] rcu: Priority-boost-related " paulmck
2020-06-23 0:21 ` [PATCH tip/core/rcu 09/26] rcu: No-CBs-related " paulmck
2020-06-23 0:21 ` [PATCH tip/core/rcu 10/26] rcu: Expedited grace-period " paulmck
2020-06-23 0:21 ` [PATCH tip/core/rcu 11/26] fs/btrfs: Add cond_resched() for try_release_extent_mapping() stalls paulmck
2020-06-23 0:21 ` [PATCH tip/core/rcu 12/26] rcu: Update comment from rsp->rcu_gp_seq to rsp->gp_seq paulmck
2020-06-23 0:21 ` [PATCH tip/core/rcu 13/26] tick/nohz: Narrow down noise while setting current task's tick dependency paulmck
2020-06-23 0:21 ` [PATCH tip/core/rcu 14/26] rcu: fix some kernel-doc warnings paulmck
2020-06-23 0:21 ` [PATCH tip/core/rcu 15/26] rcu: Remove initialized but unused rnp from check_slow_task() paulmck
2020-06-23 0:21 ` [PATCH tip/core/rcu 16/26] rcu: Mark rcu_nmi_enter() call to rcu_cleanup_after_idle() noinstr paulmck
2020-06-23 17:04 ` Peter Zijlstra
2020-06-23 17:50 ` Paul E. McKenney
2020-06-23 0:21 ` [PATCH tip/core/rcu 17/26] lockdep: Complain only once about RCU in extended quiescent state paulmck
2020-06-23 0:21 ` [PATCH tip/core/rcu 18/26] rcu: Replace 1 with true paulmck
2020-06-23 0:21 ` [PATCH tip/core/rcu 19/26] rcu: Stop shrinker loop paulmck
2020-06-23 0:21 ` [PATCH tip/core/rcu 20/26] rcu: gp_max is protected by root rcu_node's lock paulmck
2020-06-23 0:21 ` [PATCH tip/core/rcu 21/26] rcu: grplo/grphi just records CPU number paulmck
2020-06-23 0:21 ` [PATCH tip/core/rcu 22/26] rcu: grpnum just records group number paulmck
2020-06-23 0:21 ` [PATCH tip/core/rcu 23/26] kernel/rcu/tree.c: Fix kernel-doc warnings paulmck
2020-06-23 0:21 ` [PATCH tip/core/rcu 24/26] rcu: fix some " paulmck
2020-06-23 0:21 ` [PATCH tip/core/rcu 25/26] rcu: Remove KCSAN stubs paulmck
2020-06-23 0:21 ` [PATCH tip/core/rcu 26/26] rcu: Remove KCSAN stubs from update.c paulmck
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