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 09/10] doc: Timer problems can cause RCU CPU stall warnings
Date: Mon, 22 Jun 2020 17:09:46 -0700 [thread overview]
Message-ID: <20200623000947.25222-9-paulmck@kernel.org> (raw)
In-Reply-To: <20200623000923.GA25047@paulmck-ThinkPad-P72>
From: "Paul E. McKenney" <paulmck@kernel.org>
Over the past few years, there have been several cases where timekeeping
bugs have caused RCU CPU stall warnings, particularly during hardware
bringup. This commit therefore adds such bugs to the list of things
that can result in RCU CPU stall warnings.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
---
Documentation/RCU/stallwarn.rst | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/Documentation/RCU/stallwarn.rst b/Documentation/RCU/stallwarn.rst
index 08bc9ae..c9ab6af 100644
--- a/Documentation/RCU/stallwarn.rst
+++ b/Documentation/RCU/stallwarn.rst
@@ -87,6 +87,13 @@ warnings:
problem really has happened, and seems to be most likely to
result in RCU CPU stall warnings for CONFIG_NO_HZ_COMMON=n kernels.
+- A hardware or software issue that prevents time-based wakeups
+ from occurring. These issues can range from misconfigured or
+ buggy timer hardware through bugs in the interrupt or exception
+ path (whether hardware, firmware, or software) through bugs
+ in Linux's timer subsystem through bugs in the scheduler, and,
+ yes, even including bugs in RCU itself.
+
- A bug in the RCU implementation.
- A hardware failure. This is quite unlikely, but has occurred
--
2.9.5
next prev parent reply other threads:[~2020-06-23 0:10 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-23 0:09 [PATCH tip/core/rcu 0/10] Documentation updates for v5.9 Paul E. McKenney
2020-06-23 0:09 ` [PATCH tip/core/rcu 01/10] docs: RCU: Convert checklist.txt to ReST paulmck
2020-06-23 0:09 ` [PATCH tip/core/rcu 02/10] docs: RCU: Convert lockdep-splat.txt " paulmck
2020-06-23 0:09 ` [PATCH tip/core/rcu 03/10] docs: RCU: Convert lockdep.txt " paulmck
2020-06-23 0:09 ` [PATCH tip/core/rcu 04/10] docs: RCU: Convert rculist_nulls.txt " paulmck
2020-06-23 0:09 ` [PATCH tip/core/rcu 05/10] docs: RCU: Convert torture.txt " paulmck
2020-06-23 0:09 ` [PATCH tip/core/rcu 06/10] docs: RCU: Convert rcuref.txt " paulmck
2020-06-23 0:09 ` [PATCH tip/core/rcu 07/10] docs: RCU: Convert stallwarn.txt " paulmck
2020-06-23 0:09 ` [PATCH tip/core/rcu 08/10] docs: RCU: Don't duplicate chapter names in rculist_nulls.rst paulmck
2020-06-23 0:09 ` paulmck [this message]
2020-06-23 0:09 ` [PATCH tip/core/rcu 10/10] doc: Tasks RCU must protect instructions before trampoline paulmck
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