On 2022/11/24 14:22, Zhen Lei wrote: > 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 "::" Hi, Bagas Sanjaya: Do you have time to review this patch again? Your review comments are important because you made comments in the previous version. > > 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 > -- Regards, Zhen Lei
