[ltt-dev] TODO list before releasing LTTng-buffering to LKML

[ltt-dev] TODO list before releasing LTTng-buffering to LKML

[Mathieu Desnoyers]

Hi!

Just to keep you posted on the current development, this is what is left
on my roadmap before I post a minimal LTTng (only the timestamping,
event ID management and buffering) to LKML :

Todo list before posting LTTng-buffering to LKML

- Create a simplified ltt-relay (use interrupt disable instead of
  lockless algo)
- merge a simplified lttv in lttng


Todo list after posting first LTTng-buffering release to LKML :

- assign marker IDs per channel
- switch ltt-control.ko (currently over netlink) to debugfs
- switch marker list (and marker activation (currently in /proc/ltt) to debugfs
  Marker directory. One file per marker.
- Create a ltt-ascii.ko kernel module which merge-sorts the buffers and exports
  them to userspace through a debugfs file.

If some of you are interested to work on any of these, you are welcome.
I'll be glad to post more details about these items upon request.

Mathieu

-- 
Mathieu Desnoyers
OpenPGP key fingerprint: 8CD5 52C3 8E3C 4140 715F  BA06 3F25 A8FE 3BAE 9A68

[ltt-dev] TODO list before releasing LTTng-buffering to LKML

[Mathieu Desnoyers]

* Mathieu Desnoyers (compudj at krystal.dyndns.org) wrote:
> Hi!
> 
> Just to keep you posted on the current development, this is what is left
> on my roadmap before I post a minimal LTTng (only the timestamping,
> event ID management and buffering) to LKML :
> 
> Todo list before posting LTTng-buffering to LKML
> 
> - Create a simplified ltt-relay (use interrupt disable instead of
>   lockless algo)

I implemented this one yesterday night. Basically, it's the original
lockless scheme, except that it uses only standard variables (no atomic
or local atomic ops) and it also uses a per-buffer spinlock (because
readers can be on different cpus) and interrupt disable. Here are the
performance results : they are not that far from the lockless scheme. It
adds about 1% performance hit on tbench on the x86_64 over the lockless
scheme. See lttng-transport-locked.patch in LTTng 0.36 for details.

Performance tests, tbench, flight recorder trace, default instrumentation

Dual quad-core x86_64, 2.0GHz

Instrumentation dynamically disabled :                           1883.09 MB/s
Markers connected :                                              1812.14 MB/s
Lockless scheme, flight recorder :                                925.68 MB/s
Per-cpu-buffer spinlock and interrupt disable, flight recorder :  871.78 MB/s
Global spinlock and interrupt disable, flight recorder :          153.74 MB/s


Single Core Pentium 4, noreplace-smp, 3.0GHz

Instrumentation dynamically disabled :                            146.85 MB/s
Markers connected :                                               144.32 MB/s
Lockless scheme, flight recorder :                                 89.59 MB/s
Per-cpu-buffer spinlock and interrupt disable, flight recorder :   86.05 MB/s

Mathieu

> - merge a simplified lttv in lttng
> 
> 
> Todo list after posting first LTTng-buffering release to LKML :
> 
> - assign marker IDs per channel
> - switch ltt-control.ko (currently over netlink) to debugfs
> - switch marker list (and marker activation (currently in /proc/ltt) to debugfs
>   Marker directory. One file per marker.
> - Create a ltt-ascii.ko kernel module which merge-sorts the buffers and exports
>   them to userspace through a debugfs file.
> 
> If some of you are interested to work on any of these, you are welcome.
> I'll be glad to post more details about these items upon request.
> 
> Mathieu
> 
> -- 
> Mathieu Desnoyers
> OpenPGP key fingerprint: 8CD5 52C3 8E3C 4140 715F  BA06 3F25 A8FE 3BAE 9A68
> 
> _______________________________________________
> ltt-dev mailing list
> ltt-dev at lists.casi.polymtl.ca
> http://lists.casi.polymtl.ca/cgi-bin/mailman/listinfo/ltt-dev
> 

-- 
Mathieu Desnoyers
OpenPGP key fingerprint: 8CD5 52C3 8E3C 4140 715F  BA06 3F25 A8FE 3BAE 9A68

[ltt-dev] TODO list before releasing LTTng-buffering to LKML

[Mathieu Desnoyers]

Hi,

Thanks for the steady work those past days.

This is mainly a status update of the TODO and request for status
feedback on the action items :

* Mathieu Desnoyers (compudj at krystal.dyndns.org) wrote:
> * Mathieu Desnoyers (compudj at krystal.dyndns.org) wrote:
> > Hi!
> > 
> > Just to keep you posted on the current development, this is what is left
> > on my roadmap before I post a minimal LTTng (only the timestamping,
> > event ID management and buffering) to LKML :
> > 
> > Todo list before posting LTTng-buffering to LKML
> > 
> > - Create a simplified ltt-relay (use interrupt disable instead of
> >   lockless algo)

Done,

> > - merge a simplified lttv in lttng

Still todo,

> > 
> > Todo list after posting first LTTng-buffering release to LKML :
> > 
> > - assign marker IDs per channel

Still todo,

> > - switch ltt-control.ko (currently over netlink) to debugfs

> > - switch marker list (and marker activation (currently in /proc/ltt) to debugfs
> >   Marker directory. One file per marker.
> > - Create a ltt-ascii.ko kernel module which merge-sorts the buffers and exports
> >   them to userspace through a debugfs file.

Being done by Fujitsu, what is the status of these items ? Do you need
help or feedback on any of those ?

Thanks and regards,

Mathieu

-- 
Mathieu Desnoyers
OpenPGP key fingerprint: 8CD5 52C3 8E3C 4140 715F  BA06 3F25 A8FE 3BAE 9A68

[ltt-dev] TODO list before releasing LTTng-buffering to LKML

[Zhaolei]

* Mathieu Desnoyers <compudj at krystal.dyndns.org>wrote:
> Hi,
> 
> Thanks for the steady work those past days.
> 
> This is mainly a status update of the TODO and request for status
> feedback on the action items :
> 
> * Mathieu Desnoyers (compudj at krystal.dyndns.org) wrote:
>> * Mathieu Desnoyers (compudj at krystal.dyndns.org) wrote:
>> > Hi!
>> > 
>> > Just to keep you posted on the current development, this is what is left
>> > on my roadmap before I post a minimal LTTng (only the timestamping,
>> > event ID management and buffering) to LKML :
>> > 
>> > Todo list before posting LTTng-buffering to LKML
>> > 
>> > - Create a simplified ltt-relay (use interrupt disable instead of
>> >   lockless algo)
> 
> Done,
> 
>> > - merge a simplified lttv in lttng
> 
> Still todo,
> 
>> > 
>> > Todo list after posting first LTTng-buffering release to LKML :
>> > 
>> > - assign marker IDs per channel
> 
> Still todo,
> 
>> > - switch ltt-control.ko (currently over netlink) to debugfs
> 
>> > - switch marker list (and marker activation (currently in /proc/ltt) to debugfs
We separated it into 3 steps,
(in 2008-10-20's ltt-maillist with title of "TODO list before releasing LTTng-buffering to LKML]")
and now we have finished a phototype of step1.
It step1's src is confirmd, we will continue step2 and 3.

We will send you src of step1 today(based on 2.6.27.2-lttng-0.46).

>> >   Marker directory. One file per marker.
We will begin it soon.

>> > - Create a ltt-ascii.ko kernel module which merge-sorts the buffers and exports
>> >   them to userspace through a debugfs file.
We will begin it soon.

> 
> Being done by Fujitsu, what is the status of these items ? Do you need
> help or feedback on any of those ?
> 
> Thanks and regards,
> 
> Mathieu
> 
> -- 
> Mathieu Desnoyers
> OpenPGP key fingerprint: 8CD5 52C3 8E3C 4140 715F  BA06 3F25 A8FE 3BAE 9A68
> 
>

[ltt-dev] TODO list before releasing LTTng-buffering to LKML

[Lai Jiangshan]

* Mathieu Desnoyers (compudj at krystal.dyndns.org) wrote:
> Hi!
> 
> Just to keep you posted on the current development, this is what is left
> on my roadmap before I post a minimal LTTng (only the timestamping,
> event ID management and buffering) to LKML :
> 
> Todo list before posting LTTng-buffering to LKML

[...]

> - switch ltt-control.ko (currently over netlink) to debugfs
> - switch marker list (and marker activation (currently in /proc/ltt) to debugfs
>   Marker directory. One file per marker.
> - Create a ltt-ascii.ko kernel module which merge-sorts the buffers and exports
>   them to userspace through a debugfs file.
> 

Hi, Mathieu,

We are interested with the above TODOs, and we are planning to implement them.

Thanks, Lai

> If some of you are interested to work on any of these, you are welcome.
> I'll be glad to post more details about these items upon request.
> 
> Mathieu
> 

[ltt-dev] TODO list before releasing LTTng-buffering to LKML

[Andrew McDermott]

Lai Jiangshan <laijs at cn.fujitsu.com> writes:

> * Mathieu Desnoyers (compudj at krystal.dyndns.org) wrote:
>> Hi!
>> 
>> Just to keep you posted on the current development, this is what is left
>> on my roadmap before I post a minimal LTTng (only the timestamping,
>> event ID management and buffering) to LKML :
>> 
>> Todo list before posting LTTng-buffering to LKML
>
> [...]
>
>> - switch ltt-control.ko (currently over netlink) to debugfs
>> - switch marker list (and marker activation (currently in /proc/ltt) to debugfs
>>   Marker directory. One file per marker.
>> - Create a ltt-ascii.ko kernel module which merge-sorts the buffers and exports
>>   them to userspace through a debugfs file.
>> 
>
> Hi, Mathieu,
>
> We are interested with the above TODOs, and we are planning to implement them.
>
> Thanks, Lai
>
>> If some of you are interested to work on any of these, you are welcome.
>> I'll be glad to post more details about these items upon request.

Do you plan on doing this work in the context of 2.6.27?  I was trying
to understand where the switch to debugfs for ltt-control and the marker
list was going to take place.

Thanks,
Andy.

>> 
>> Mathieu
>> 
>
>
>
> _______________________________________________
> ltt-dev mailing list
> ltt-dev at lists.casi.polymtl.ca
> http://lists.casi.polymtl.ca/cgi-bin/mailman/listinfo/ltt-dev

-- 
andy