[PATCH v3] doc: Fix htmldocs build warnings of stallwarn.rst

From: Zhen Lei
Date: Thu Nov 24 2022 - 01:22:26 EST


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@xxxxxxxxxxxxxxxx/
Fixes: 3d2788ba4573 ("doc: Document CONFIG_RCU_CPU_STALL_CPUTIME=y stall information")
Reported-by: Stephen Rothwell <sfr@xxxxxxxxxxxxxxxx>
Signed-off-by: Zhen Lei <thunder.leizhen@xxxxxxxxxx>
---
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