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doc: Fix htmldocs build warnings of stallwarn.rst 

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 needs to be indented, so this commit adds 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>
Tested-by: Akira Yokosawa <akiyks@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
This commit is contained in:
Zhen Lei 2022-11-24 14:22:03 +08:00 committed by Paul E. McKenney
parent eff864590b
commit 5e013dc17e
1 changed files with 30 additions and 26 deletions
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56
Documentation/RCU/stallwarn.rst
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@ -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