[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <1c472632-caf6-72d3-5de8-aaa3a1fdfd61@huawei.com>
Date: Sat, 26 Nov 2022 09:30:32 +0800
From: "Leizhen (ThunderTown)" <thunder.leizhen@...wei.com>
To: "Paul E . McKenney" <paulmck@...nel.org>,
Frederic Weisbecker <frederic@...nel.org>,
Neeraj Upadhyay <quic_neeraju@...cinc.com>,
"Josh Triplett" <josh@...htriplett.org>,
Steven Rostedt <rostedt@...dmis.org>,
Mathieu Desnoyers <mathieu.desnoyers@...icios.com>,
Lai Jiangshan <jiangshanlai@...il.com>,
Joel Fernandes <joel@...lfernandes.org>, <rcu@...r.kernel.org>,
<linux-kernel@...r.kernel.org>,
Stephen Rothwell <sfr@...b.auug.org.au>,
<linux-next@...r.kernel.org>
CC: Bagas Sanjaya <bagasdotme@...il.com>
Subject: Re: [PATCH v3] doc: Fix htmldocs build warnings of stallwarn.rst
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@canb.auug.org.au/
> Fixes: 3d2788ba4573 ("doc: Document CONFIG_RCU_CPU_STALL_CPUTIME=y stall information")
> Reported-by: Stephen Rothwell <sfr@...b.auug.org.au>
> Signed-off-by: Zhen Lei <thunder.leizhen@...wei.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 "::"
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
Powered by blists - more mailing lists