From: "Leizhen (ThunderTown)" <thunder.leizhen@huawei.com>
To: "Elliott, Robert (Servers)" <elliott@hpe.com>,
"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" <rcu@vger.kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v6 1/2] rcu: Add RCU stall diagnosis information
Date: Thu, 10 Nov 2022 16:27:35 +0800 [thread overview]
Message-ID: <4e93b955-28bf-7b9d-14af-7681b47fada7@huawei.com> (raw)
In-Reply-To: <MW5PR84MB18423CA291ABCD3DCCE3D416AB3E9@MW5PR84MB1842.NAMPRD84.PROD.OUTLOOK.COM>
On 2022/11/10 0:55, Elliott, Robert (Servers) wrote:
>
>
>> b/Documentation/admin-guide/kernel-parameters.txt
>> index a465d5242774af8..2729f3ad11d108b 100644
>> --- a/Documentation/admin-guide/kernel-parameters.txt
>> +++ b/Documentation/admin-guide/kernel-parameters.txt
>> @@ -5082,6 +5082,12 @@
>> rcupdate.rcu_cpu_stall_timeout to be used (after
>> conversion from seconds to milliseconds).
>>
>> + rcupdate.rcu_cpu_stall_cputime= [KNL]
>> + Provide statistics on the cputime and count of
>> + interrupts and tasks during the sampling period. For
>> + multiple continuous RCU stalls, all sampling periods
>> + begin at half of the first RCU stall timeout.
>
> This description should start with:
> "In kernels built with CONFIG_RCU_CPU_STALL_TIME=y, "
>
> Also, that parameter name seems like it contains a time value, but
> it's really just treated as zero vs. anything else. Consider renaming
> it to rcu_cpu_stall_cputime_en or describing the values in the
> description ("0 disables, all other values enable").
>
>> diff --git a/kernel/rcu/tree.h b/kernel/rcu/tree.h
>> +struct rcu_snap_record {
>> + unsigned long gp_seq; /* Track rdp->gp_seq counter */
>> + u64 cputime_irq; /* Accumulated cputime of hard irqs */
>> + u64 cputime_softirq;/* Accumulated cputime of soft irqs */
>> + u64 cputime_system; /* Accumulated cputime of kernel tasks
>> */
>> + unsigned long nr_hardirqs; /* Accumulated number of hard irqs */
>> + unsigned int nr_softirqs; /* Accumulated number of soft irqs */
>
> That should be "unsigned long" to match the other patch
We have discussed this before. And you mentioned:
irqs_sumstruct kernel_stat {
unsigned long irqs_sum;
unsigned int softirqs[NR_SOFTIRQS];
};
The softirqs field is an unsigned int, so the new function doesn't have
this inconsistency.
>
>
>> diff --git a/kernel/rcu/tree_stall.h b/kernel/rcu/tree_stall.h
>> +static void print_cpu_stat_info(int cpu)
>> +{
> ...
>> + pr_err(" hardirqs softirqs csw/system\n");
>> + pr_err(" number: %8ld %10d %12lld\n",
>> + kstat_cpu_irqs_sum(cpu) - rsrp->nr_hardirqs,
>> + kstat_cpu_softirqs_sum(cpu) - rsrp->nr_softirqs,
>> + nr_context_switches_cpu(cpu) - rsrp->nr_csw);
>> + pr_err("cputime: %8lld %10lld %12lld ==> %lld(ms)\n",
>
> Those should all start with "\t" to match other related prints.
Right, thanks.
>
>
> .
>
--
Regards,
Zhen Lei
next prev parent reply other threads:[~2022-11-10 8:27 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-11-09 9:37 [PATCH v6 0/2] rcu: Add RCU stall diagnosis information Zhen Lei
2022-11-09 9:37 ` [PATCH v6 1/2] " Zhen Lei
2022-11-09 15:20 ` Frederic Weisbecker
2022-11-10 6:55 ` Leizhen (ThunderTown)
2022-11-09 16:55 ` Elliott, Robert (Servers)
2022-11-09 17:03 ` Elliott, Robert (Servers)
2022-11-10 8:27 ` Leizhen (ThunderTown) [this message]
2022-11-09 9:37 ` [PATCH v6 2/2] doc: Document CONFIG_RCU_CPU_STALL_CPUTIME=y stall information Zhen Lei
2022-11-09 15:08 ` Frederic Weisbecker
2022-11-10 2:54 ` Leizhen (ThunderTown)
2022-11-09 15:26 ` [PATCH v6 0/2] rcu: Add RCU stall diagnosis information Frederic Weisbecker
2022-11-09 15:59 ` Paul E. McKenney
2022-11-09 17:03 ` Frederic Weisbecker
2022-11-09 17:22 ` Paul E. McKenney
2022-11-10 2:27 ` Leizhen (ThunderTown)
2022-11-12 18:59 ` Paul E. McKenney
2022-11-15 9:11 ` Leizhen (ThunderTown)
2022-11-10 7:29 ` Leizhen (ThunderTown)
2022-11-10 11:35 ` Frederic Weisbecker
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=4e93b955-28bf-7b9d-14af-7681b47fada7@huawei.com \
--to=thunder.leizhen@huawei.com \
--cc=elliott@hpe.com \
--cc=frederic@kernel.org \
--cc=jiangshanlai@gmail.com \
--cc=joel@joelfernandes.org \
--cc=josh@joshtriplett.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mathieu.desnoyers@efficios.com \
--cc=paulmck@kernel.org \
--cc=quic_neeraju@quicinc.com \
--cc=rcu@vger.kernel.org \
--cc=rostedt@goodmis.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.