From: Zhen Lei <thunder.leizhen@huawei.com>
To: "Paul E . McKenney" <paulmck@kernel.org>,
Frederic Weisbecker <frederic@kernel.org>,
Neeraj Upadhyay <quic_neeraju@quicinc.com>,
"Josh Triplett" <josh@joshtriplett.org>,
Steven Rostedt <rostedt@goodmis.org>,
Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
Lai Jiangshan <jiangshanlai@gmail.com>,
Joel Fernandes <joel@joelfernandes.org>, <rcu@vger.kernel.org>,
<linux-kernel@vger.kernel.org>,
Stephen Rothwell <sfr@canb.auug.org.au>,
<linux-next@vger.kernel.org>
Cc: Zhen Lei <thunder.leizhen@huawei.com>,
Bagas Sanjaya <bagasdotme@gmail.com>
Subject: [PATCH v3] doc: Fix htmldocs build warnings of stallwarn.rst
Date: Thu, 24 Nov 2022 14:22:03 +0800 [thread overview]
Message-ID: <20221124062204.1932-1-thunder.leizhen@huawei.com> (raw)
Documentation/RCU/stallwarn.rst:
401: WARNING: Literal block expected; none found.
428: WARNING: Literal block expected; none found.
445: WARNING: Literal block expected; none found.
459: WARNING: Literal block expected; none found.
468: WARNING: Literal block expected; none found.
The literal block need to be indented, so add two spaces to each line.
In addition, ':', which is used as a boundary in the literal block, is
replaced by '|'.
Link: https://lore.kernel.org/linux-next/20221123163255.48653674@canb.auug.org.au/
Fixes: 3d2788ba4573 ("doc: Document CONFIG_RCU_CPU_STALL_CPUTIME=y stall information")
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
---
Documentation/RCU/stallwarn.rst | 56 ++++++++++++++++++---------------
1 file changed, 30 insertions(+), 26 deletions(-)
v2 --> v3:
1. Add "Link:", "Fixes:", "Reported-by:".
2. Remove a orphaned pipe (|).
3. Change ". ::" to "::"
v1 --> v2:
For the case that both colons need to be deleted, change "::" to expanded
form or partially minimized form.
diff --git a/Documentation/RCU/stallwarn.rst b/Documentation/RCU/stallwarn.rst
index c1e92dfef40d501..ca7b7cd806a16c9 100644
--- a/Documentation/RCU/stallwarn.rst
+++ b/Documentation/RCU/stallwarn.rst
@@ -398,9 +398,9 @@ In kernels built with CONFIG_RCU_CPU_STALL_CPUTIME=y or booted with
rcupdate.rcu_cpu_stall_cputime=1, the following additional information
is supplied with each RCU CPU stall warning::
-rcu: hardirqs softirqs csw/system
-rcu: number: 624 45 0
-rcu: cputime: 69 1 2425 ==> 2500(ms)
+ rcu: hardirqs softirqs csw/system
+ rcu: number: 624 45 0
+ rcu: cputime: 69 1 2425 ==> 2500(ms)
These statistics are collected during the sampling period. The values
in row "number:" are the number of hard interrupts, number of soft
@@ -412,22 +412,24 @@ in milliseconds. Because user-mode tasks normally do not cause RCU CPU
stalls, these tasks are typically kernel tasks, which is why only the
system CPU time are considered.
-The sampling period is shown as follows:
-:<------------first timeout---------->:<-----second timeout----->:
-:<--half timeout-->:<--half timeout-->: :
-: :<--first period-->: :
-: :<-----------second sampling period---------->:
-: : : :
-: snapshot time point 1st-stall 2nd-stall
+The sampling period is shown as follows::
+ |<------------first timeout---------->|<-----second timeout----->|
+ |<--half timeout-->|<--half timeout-->| |
+ | |<--first period-->| |
+ | |<-----------second sampling period---------->|
+ | | | |
+ snapshot time point 1st-stall 2nd-stall
The following describes four typical scenarios:
-1. A CPU looping with interrupts disabled.::
+1. A CPU looping with interrupts disabled.
- rcu: hardirqs softirqs csw/system
- rcu: number: 0 0 0
- rcu: cputime: 0 0 0 ==> 2500(ms)
+ ::
+
+ rcu: hardirqs softirqs csw/system
+ rcu: number: 0 0 0
+ rcu: cputime: 0 0 0 ==> 2500(ms)
Because interrupts have been disabled throughout the measurement
interval, there are no interrupts and no context switches.
@@ -440,11 +442,11 @@ The following describes four typical scenarios:
This is similar to the previous example, but with non-zero number of
and CPU time consumed by hard interrupts, along with non-zero CPU
- time consumed by in-kernel execution.::
+ time consumed by in-kernel execution::
- rcu: hardirqs softirqs csw/system
- rcu: number: 624 0 0
- rcu: cputime: 49 0 2446 ==> 2500(ms)
+ rcu: hardirqs softirqs csw/system
+ rcu: number: 624 0 0
+ rcu: cputime: 49 0 2446 ==> 2500(ms)
The fact that there are zero softirqs gives a hint that these were
disabled, perhaps via local_bh_disable(). It is of course possible
@@ -454,20 +456,22 @@ The following describes four typical scenarios:
3. A CPU looping with preemption disabled.
- Here, only the number of context switches is zero.::
+ Here, only the number of context switches is zero::
- rcu: hardirqs softirqs csw/system
- rcu: number: 624 45 0
- rcu: cputime: 69 1 2425 ==> 2500(ms)
+ rcu: hardirqs softirqs csw/system
+ rcu: number: 624 45 0
+ rcu: cputime: 69 1 2425 ==> 2500(ms)
This situation hints that the stalled CPU was looping with preemption
disabled.
-4. No looping, but massive hard and soft interrupts.::
+4. No looping, but massive hard and soft interrupts.
+
+ ::
- rcu: hardirqs softirqs csw/system
- rcu: number: xx xx 0
- rcu: cputime: xx xx 0 ==> 2500(ms)
+ rcu: hardirqs softirqs csw/system
+ rcu: number: xx xx 0
+ rcu: cputime: xx xx 0 ==> 2500(ms)
Here, the number and CPU time of hard interrupts are all non-zero,
but the number of context switches and the in-kernel CPU time consumed
--
2.25.1
next reply other threads:[~2022-11-24 6:22 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-11-24 6:22 Zhen Lei [this message]
2022-11-26 1:30 ` [PATCH v3] doc: Fix htmldocs build warnings of stallwarn.rst Leizhen (ThunderTown)
2022-11-28 4:03 ` Bagas Sanjaya
2022-11-26 3:09 ` Akira Yokosawa
2022-11-29 1:07 ` Paul E. McKenney
2022-11-28 4:08 ` Bagas Sanjaya
2022-11-28 7:05 ` Leizhen (ThunderTown)
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