2016-10-05 07:06:33

by Angel Shtilianov

[permalink] [raw]
Subject: [PATCH] rcu: Reword help of RCU_TRACE option

Explicitly state that enabling RCU_TRACE enables more
tracepoints and not just "additional tracing".

Signed-off-by: Nikolay Borisov <[email protected]>
---

Hello Paul,

Following our latest conversation re. enabling RCU tracing
I had to actually go and look into the code to see which
option enables the additional tracepoints. I wasn't sure
while reading the help of TRACE_RCU. So here is a patch
which explicitly states that this enables additional
tracepoints.

Apply it if you deem necessary it might be just me that
thinks the description is not verbose enough.

lib/Kconfig.debug | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index cab7405f48d2..f8c3468ec7ef 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -1429,8 +1429,8 @@ config RCU_TRACE
depends on DEBUG_KERNEL
select TRACE_CLOCK
help
- This option provides tracing in RCU which presents stats
- in debugfs for debugging RCU implementation.
+ This option enables additional tracepoints in RCU which present
+ stats in debugfs for debugging RCU implementation.

Say Y here if you want to enable RCU tracing
Say N if you are unsure.
--
2.5.0


2016-10-05 14:03:17

by Paul E. McKenney

[permalink] [raw]
Subject: Re: [PATCH] rcu: Reword help of RCU_TRACE option

On Wed, Oct 05, 2016 at 10:06:21AM +0300, Nikolay Borisov wrote:
> Explicitly state that enabling RCU_TRACE enables more
> tracepoints and not just "additional tracing".
>
> Signed-off-by: Nikolay Borisov <[email protected]>
> ---
>
> Hello Paul,
>
> Following our latest conversation re. enabling RCU tracing
> I had to actually go and look into the code to see which
> option enables the additional tracepoints. I wasn't sure
> while reading the help of TRACE_RCU. So here is a patch
> which explicitly states that this enables additional
> tracepoints.
>
> Apply it if you deem necessary it might be just me that
> thinks the description is not verbose enough.
>
> lib/Kconfig.debug | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
> index cab7405f48d2..f8c3468ec7ef 100644
> --- a/lib/Kconfig.debug
> +++ b/lib/Kconfig.debug
> @@ -1429,8 +1429,8 @@ config RCU_TRACE
> depends on DEBUG_KERNEL
> select TRACE_CLOCK
> help
> - This option provides tracing in RCU which presents stats
> - in debugfs for debugging RCU implementation.
> + This option enables additional tracepoints in RCU which present
> + stats in debugfs for debugging RCU implementation.

How about something like this?

This option provides tracing in RCU which presents stats
in debugfs for debugging RCU implementation. It also enables
additional tracepoints for ftrace-style event tracing.

Thanx, Paul

>
> Say Y here if you want to enable RCU tracing
> Say N if you are unsure.
> --
> 2.5.0
>

2016-10-05 14:18:14

by Angel Shtilianov

[permalink] [raw]
Subject: Re: [PATCH] rcu: Reword help of RCU_TRACE option



On 10/05/2016 05:03 PM, Paul E. McKenney wrote:
> On Wed, Oct 05, 2016 at 10:06:21AM +0300, Nikolay Borisov wrote:
>> Explicitly state that enabling RCU_TRACE enables more
>> tracepoints and not just "additional tracing".
>>
>> Signed-off-by: Nikolay Borisov <[email protected]>
>> ---
>>
>> Hello Paul,
>>
>> Following our latest conversation re. enabling RCU tracing
>> I had to actually go and look into the code to see which
>> option enables the additional tracepoints. I wasn't sure
>> while reading the help of TRACE_RCU. So here is a patch
>> which explicitly states that this enables additional
>> tracepoints.
>>
>> Apply it if you deem necessary it might be just me that
>> thinks the description is not verbose enough.
>>
>> lib/Kconfig.debug | 4 ++--
>> 1 file changed, 2 insertions(+), 2 deletions(-)
>>
>> diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
>> index cab7405f48d2..f8c3468ec7ef 100644
>> --- a/lib/Kconfig.debug
>> +++ b/lib/Kconfig.debug
>> @@ -1429,8 +1429,8 @@ config RCU_TRACE
>> depends on DEBUG_KERNEL
>> select TRACE_CLOCK
>> help
>> - This option provides tracing in RCU which presents stats
>> - in debugfs for debugging RCU implementation.
>> + This option enables additional tracepoints in RCU which present
>> + stats in debugfs for debugging RCU implementation.
>
> How about something like this?
>
> This option provides tracing in RCU which presents stats
> in debugfs for debugging RCU implementation. It also enables
> additional tracepoints for ftrace-style event tracing.

So long as it's explicitly stated that it also enables tracepoints it's
all fine by me. Apparently I'm not the only one who got confused. In a
question re. CONFIG_RCU_TRACE here is what someone said on IRC:

"what's tracepoints do you mean? this option enables the additional
statistics permanently."

Care to apply it with the revised wording or shall I resend?

>
> Thanx, Paul
>
>>
>> Say Y here if you want to enable RCU tracing
>> Say N if you are unsure.
>> --
>> 2.5.0
>>
>

2016-10-06 12:46:10

by Paul E. McKenney

[permalink] [raw]
Subject: Re: [PATCH] rcu: Reword help of RCU_TRACE option

On Wed, Oct 05, 2016 at 05:18:09PM +0300, Nikolay Borisov wrote:
>
>
> On 10/05/2016 05:03 PM, Paul E. McKenney wrote:
> > On Wed, Oct 05, 2016 at 10:06:21AM +0300, Nikolay Borisov wrote:
> >> Explicitly state that enabling RCU_TRACE enables more
> >> tracepoints and not just "additional tracing".
> >>
> >> Signed-off-by: Nikolay Borisov <[email protected]>
> >> ---
> >>
> >> Hello Paul,
> >>
> >> Following our latest conversation re. enabling RCU tracing
> >> I had to actually go and look into the code to see which
> >> option enables the additional tracepoints. I wasn't sure
> >> while reading the help of TRACE_RCU. So here is a patch
> >> which explicitly states that this enables additional
> >> tracepoints.
> >>
> >> Apply it if you deem necessary it might be just me that
> >> thinks the description is not verbose enough.
> >>
> >> lib/Kconfig.debug | 4 ++--
> >> 1 file changed, 2 insertions(+), 2 deletions(-)
> >>
> >> diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
> >> index cab7405f48d2..f8c3468ec7ef 100644
> >> --- a/lib/Kconfig.debug
> >> +++ b/lib/Kconfig.debug
> >> @@ -1429,8 +1429,8 @@ config RCU_TRACE
> >> depends on DEBUG_KERNEL
> >> select TRACE_CLOCK
> >> help
> >> - This option provides tracing in RCU which presents stats
> >> - in debugfs for debugging RCU implementation.
> >> + This option enables additional tracepoints in RCU which present
> >> + stats in debugfs for debugging RCU implementation.
> >
> > How about something like this?
> >
> > This option provides tracing in RCU which presents stats
> > in debugfs for debugging RCU implementation. It also enables
> > additional tracepoints for ftrace-style event tracing.
>
> So long as it's explicitly stated that it also enables tracepoints it's
> all fine by me. Apparently I'm not the only one who got confused. In a
> question re. CONFIG_RCU_TRACE here is what someone said on IRC:
>
> "what's tracepoints do you mean? this option enables the additional
> statistics permanently."
>
> Care to apply it with the revised wording or shall I resend?

Please see below for the current state.

Thanx, Paul

------------------------------------------------------------------------

commit a30cd69bdcb1ae12cb243e75eddd608c1798d438
Author: Nikolay Borisov <[email protected]>
Date: Thu Oct 6 05:42:39 2016 -0700

rcu: RCU_TRACE enables event tracing as well as debugfs

The commit brings the RCU_TRACE Kconfig option's help text up to date
by noting that it enables additional event tracing as well as debugfs.

Signed-off-by: Nikolay Borisov <[email protected]>
[ paulmck: Do some wordsmithing. ]
Signed-off-by: Paul E. McKenney <[email protected]>

diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 2b5441812214..7f8e8f3c72ea 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -1450,7 +1450,8 @@ config RCU_TRACE
select TRACE_CLOCK
help
This option provides tracing in RCU which presents stats
- in debugfs for debugging RCU implementation.
+ in debugfs for debugging RCU implementation. It also enables
+ additional tracepoints for ftrace-style event tracing.

Say Y here if you want to enable RCU tracing
Say N if you are unsure.

2016-10-06 12:51:48

by Angel Shtilianov

[permalink] [raw]
Subject: Re: [PATCH] rcu: Reword help of RCU_TRACE option



On 10/06/2016 03:45 PM, Paul E. McKenney wrote:
> On Wed, Oct 05, 2016 at 05:18:09PM +0300, Nikolay Borisov wrote:
>>
>>
>> On 10/05/2016 05:03 PM, Paul E. McKenney wrote:
>>> On Wed, Oct 05, 2016 at 10:06:21AM +0300, Nikolay Borisov wrote:
>>>> Explicitly state that enabling RCU_TRACE enables more
>>>> tracepoints and not just "additional tracing".
>>>>
>>>> Signed-off-by: Nikolay Borisov <[email protected]>
>>>> ---
>>>>
>>>> Hello Paul,
>>>>
>>>> Following our latest conversation re. enabling RCU tracing
>>>> I had to actually go and look into the code to see which
>>>> option enables the additional tracepoints. I wasn't sure
>>>> while reading the help of TRACE_RCU. So here is a patch
>>>> which explicitly states that this enables additional
>>>> tracepoints.
>>>>
>>>> Apply it if you deem necessary it might be just me that
>>>> thinks the description is not verbose enough.
>>>>
>>>> lib/Kconfig.debug | 4 ++--
>>>> 1 file changed, 2 insertions(+), 2 deletions(-)
>>>>
>>>> diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
>>>> index cab7405f48d2..f8c3468ec7ef 100644
>>>> --- a/lib/Kconfig.debug
>>>> +++ b/lib/Kconfig.debug
>>>> @@ -1429,8 +1429,8 @@ config RCU_TRACE
>>>> depends on DEBUG_KERNEL
>>>> select TRACE_CLOCK
>>>> help
>>>> - This option provides tracing in RCU which presents stats
>>>> - in debugfs for debugging RCU implementation.
>>>> + This option enables additional tracepoints in RCU which present
>>>> + stats in debugfs for debugging RCU implementation.
>>>
>>> How about something like this?
>>>
>>> This option provides tracing in RCU which presents stats
>>> in debugfs for debugging RCU implementation. It also enables
>>> additional tracepoints for ftrace-style event tracing.
>>
>> So long as it's explicitly stated that it also enables tracepoints it's
>> all fine by me. Apparently I'm not the only one who got confused. In a
>> question re. CONFIG_RCU_TRACE here is what someone said on IRC:
>>
>> "what's tracepoints do you mean? this option enables the additional
>> statistics permanently."
>>
>> Care to apply it with the revised wording or shall I resend?
>
> Please see below for the current state.
>
> Thanx, Paul

Splendid, ACK.




>
> ------------------------------------------------------------------------
>
> commit a30cd69bdcb1ae12cb243e75eddd608c1798d438
> Author: Nikolay Borisov <[email protected]>
> Date: Thu Oct 6 05:42:39 2016 -0700
>
> rcu: RCU_TRACE enables event tracing as well as debugfs
>
> The commit brings the RCU_TRACE Kconfig option's help text up to date
> by noting that it enables additional event tracing as well as debugfs.
>
> Signed-off-by: Nikolay Borisov <[email protected]>
> [ paulmck: Do some wordsmithing. ]
> Signed-off-by: Paul E. McKenney <[email protected]>
>
> diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
> index 2b5441812214..7f8e8f3c72ea 100644
> --- a/lib/Kconfig.debug
> +++ b/lib/Kconfig.debug
> @@ -1450,7 +1450,8 @@ config RCU_TRACE
> select TRACE_CLOCK
> help
> This option provides tracing in RCU which presents stats
> - in debugfs for debugging RCU implementation.
> + in debugfs for debugging RCU implementation. It also enables
> + additional tracepoints for ftrace-style event tracing.
>
> Say Y here if you want to enable RCU tracing
> Say N if you are unsure.
>