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 05/26] rcu: Add comment documenting rcu_callback_map's purpose
Date: Mon, 22 Jun 2020 17:21:26 -0700 [thread overview]
Message-ID: <20200623002147.25750-5-paulmck@kernel.org> (raw)
In-Reply-To: <20200623002128.GA25456@paulmck-ThinkPad-P72>
From: "Paul E. McKenney" <paulmck@kernel.org>
The rcu_callback_map lockdep_map structure was added back in 2013, but
its purpose has become obscure. This commit therefore documments that the
purpose of rcu_callback map is, in the words of commit 24ef659a857 ("rcu:
Provide better diagnostics for blocking in RCU callback functions"),
to help lockdep to tie an "inappropriate voluntary context switch back
to the fact that the function is being invoked from within a callback."
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
---
kernel/rcu/update.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/kernel/rcu/update.c b/kernel/rcu/update.c
index f5a82e1..ca17b77 100644
--- a/kernel/rcu/update.c
+++ b/kernel/rcu/update.c
@@ -279,6 +279,7 @@ struct lockdep_map rcu_sched_lock_map = {
};
EXPORT_SYMBOL_GPL(rcu_sched_lock_map);
+// Tell lockdep when RCU callbacks are being invoked.
static struct lock_class_key rcu_callback_key;
struct lockdep_map rcu_callback_map =
STATIC_LOCKDEP_MAP_INIT("rcu_callback", &rcu_callback_key);
--
2.9.5
next prev parent reply other threads:[~2020-06-23 0:22 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 ` [PATCH tip/core/rcu 04/26] rcu: Add callbacks-invoked counters paulmck
2020-06-23 0:21 ` paulmck [this message]
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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