I am a volunteer

I am a volunteer

[Davi Leal]

Hi,

I would like to carry out some easy task, as realize a clean up replacing the 
use of one old function for another new one.

I do not have any problem with C, Git, etc.

Please, let me know what I can do.

Re: I am a volunteer

[Tom Spink]

2008/5/25 Davi Leal <davi@leals.com>:
> Hi,

Hi Davi,

> I would like to carry out some easy task, as realize a clean up replacing the
> use of one old function for another new one.
>
> I do not have any problem with C, Git, etc.
>
> Please, let me know what I can do.

http://kernelnewbies.org/

-- 
Tom Spink

Re: I am a volunteer

[Bart Van Assche]

On Sun, May 25, 2008 at 6:14 PM, Tom Spink <tspink@gmail.com> wrote:
> 2008/5/25 Davi Leal <davi@leals.com>:
>> I would like to carry out some easy task, as realize a clean up replacing the
>> use of one old function for another new one.
>
> http://kernelnewbies.org/

The above URL points to a page with a.o. a link to the kernel janitors
to do list, which might be what you are looking for:
http://kernelnewbies.org/KernelJanitors/Todo.

Bart.

Re: I am a volunteer

[Davi Leal]

Bart Van Assche wrote:
> > http://kernelnewbies.org/
>
> The above URL points to a page with a.o. a link to the kernel janitors
> to do list, which might be what you are looking for:
> http://kernelnewbies.org/KernelJanitors/Todo.

>From the above link I have picked the below task. If that is already done I 
will pick another easy one. Any correction, suggestion, etc. is welcome:

  * Code that depends on LINUX_VERSION_CODE & KERNEL_VERSION < 2.6 can be
    * deleted in most cases. (Mostly/all? done)


Against what git repository should I do the check, 
linux/kernel/git/torvalds/linux-2.6.git ?

P.S.: I have subscribed to kernel-janitors, etc.

Re: I was a volunteer

[Davi Leal]

>   * Code that depends on LINUX_VERSION_CODE & KERNEL_VERSION < 2.6 can be
>     * deleted in most cases. (Mostly/all? done)

The above task seems already done in git/torvalds/linux-2.6.git . Maybe you 
could remove it from http://kernelnewbies.org/KernelJanitors/Todo/ApiChanges


The below one seems to be done too:

  * Replace (un)register_ioctl32_conversion with ioctl_compat



P.S.: I am going to postpound my contribution due to others tasks are complex 
for me now.

Re: I am a volunteer

[Adrian Bunk]

On Sun, May 25, 2008 at 06:12:41PM +0200, Davi Leal wrote:
> Hi,
> 
> I would like to carry out some easy task, as realize a clean up replacing the 
> use of one old function for another new one.
> 
> I do not have any problem with C, Git, etc.
> 
> Please, let me know what I can do.

The easiest and very valuable task is testing the kernel as described at
  http://kernelnewbies.org/KernelTesters

cu
Adrian

-- 

       "Is there not promise of rain?" Ling Tan asked suddenly out
        of the darkness. There had been need of rain for many days.
       "Only a promise," Lao Er said.
                                       Pearl S. Buck - Dragon Seed

Re: I am a volunteer

[Davi Leal]

Adrian Bunk wrote:
> The easiest and very valuable task is testing the kernel as described at
>   http://kernelnewbies.org/KernelTesters

I am more motivated to do development than testing.

Re: I am a volunteer

[Willy Tarreau]

On Sun, May 25, 2008 at 08:23:22PM +0200, Davi Leal wrote:
> Adrian Bunk wrote:
> > The easiest and very valuable task is testing the kernel as described at
> >   http://kernelnewbies.org/KernelTesters
> 
> I am more motivated to do development than testing.

And who do you think will test your dev then ?

Testing very quickly involves development because you will notice bugs
first, then missing chunks of code to handle special conditions, and by
this time you will feel much better with kernel internals and will have
no problem starting on more complex tasks.

Also, we're wondering what motivates newcomers to directly dive into
development instead of testing. Would you please explain a bit about
your motivations ? It would help distribute more interesting work to
newcomers, or maybe assign them more credits if it is what they are
seeking.

Willy

Re: I am a volunteer

[Davi Leal]

Willy Tarreau wrote:
> Davi Leal wrote:
> > I am more motivated to do development than testing.
>
> And who do you think will test your dev then ?

My dev me, of course.  Your dev you, or me but only if I have time.


> Testing very quickly involves development because you will notice bugs
> first, then missing chunks of code to handle special conditions, and by
> this time you will feel much better with kernel internals and will have
> no problem starting on more complex tasks.

I just note I am already running 2.6.25.4 build by hand, etc. Has 2.6.25.4 
some regression which I could test?  Note below my time constraints.

> Also, we're wondering what motivates newcomers to directly dive into
> development instead of testing. Would you please explain a bit about
> your motivations ? It would help distribute more interesting work to
> newcomers, or maybe assign them more credits if it is what they are
> seeking.

In my case I am not looking for credit but for learning. I can only spend one 
hour each day to this subject. Tasks which would require a deadline would be 
a problem for me.

To start, I would like somebody point me to something easy to do, taking into 
account such time constraints.

Something that would require the installation of Xen to be able to reproduce 
and debug a specific bug via Xen serial port would be cool.  Anyway just 
point me to something...

Re: I am a volunteer

[Willy Tarreau]

On Sun, May 25, 2008 at 10:44:52PM +0200, Davi Leal wrote:
> Willy Tarreau wrote:
> > Davi Leal wrote:
> > > I am more motivated to do development than testing.
> >
> > And who do you think will test your dev then ?
> 
> My dev me, of course.  Your dev you, or me but only if I have time.

This is precisely one of our big problems right now. Software is almost
only tested by authors, which means that we accumulate a lot of bugs due
to lack of precise knowledge in every area. Locking bugs and lack of
pointer validation come to mind.

> > Testing very quickly involves development because you will notice bugs
> > first, then missing chunks of code to handle special conditions, and by
> > this time you will feel much better with kernel internals and will have
> > no problem starting on more complex tasks.
> 
> I just note I am already running 2.6.25.4 build by hand, etc. Has 2.6.25.4 
> some regression which I could test?  Note below my time constraints.

Rafael Wysocki regularly sends a compiled list of known regressions. A
lot of them require specific hardware to trigger a driver bug, but there
are others with reproducers (and BTW you might also have some of the
required hardware).

Arjan van de Ven has posted a list of the top 10 oopses (check
www.kerneloops.org). It's not always easy to trigger such bugs,
but you may find it interesting to read the functions spotted in
the stack traces and try to understand how they work together.

> > Also, we're wondering what motivates newcomers to directly dive into
> > development instead of testing. Would you please explain a bit about
> > your motivations ? It would help distribute more interesting work to
> > newcomers, or maybe assign them more credits if it is what they are
> > seeking.
> 
> In my case I am not looking for credit but for learning. I can only spend one 
> hour each day to this subject. Tasks which would require a deadline would be 
> a problem for me.

As Linus often says : "read the sources". Reading the code of all of a
call chain between a syscall and an oops can be *very* instructive. You
need serious motivation though. At first you will think that you don't
understand a damn thing. That's normal and expected. It does it to me
each time I stuff my nose in a file. You just need not to suppose what
a function or macro does, but to read it. You'll quickly understand what
the code does, and very likely both find stupid bugs and understand the
kernel internals.

> To start, I would like somebody point me to something easy to do, taking into 
> account such time constraints.

reading code is 100% compatible with time constraints, as there is no
deadline. You can even say that a bug that you don't look at may stay
there for years. And quite frankly, spending more than one hour every
evening on code is generally enough to give you a headache. But you
will progress very quickly.

> Something that would require the installation of Xen to be able to reproduce 
> and debug a specific bug via Xen serial port would be cool.

That's a good idea, though I have no clue how to proceed.

> Anyway just point me to something...

Please check the list for Arjan and Rafael's posts. Take something which
seems close to an area you would like to progress in. Maybe you're more
interested in writing drivers, file-systems, schedulers, VM, etc...

Regards,
Willy

Re: I am a volunteer

[Jörn Engel]

On Sun, 25 May 2008 23:00:51 +0200, Willy Tarreau wrote:
> 
> reading code is 100% compatible with time constraints, as there is no
> deadline. You can even say that a bug that you don't look at may stay
> there for years. And quite frankly, spending more than one hour every
> evening on code is generally enough to give you a headache. But you
> will progress very quickly.

When looking for something to improve, it often helps to write a new
code checker or run an existing one.  If you don't know anything better,
you can write a script that runs Lindent, takes the diff between the
original file and the Lindent version and sorts files by diff size.

The point of this excercise is not to run Lindent on every file and
submit patches for that.  But most code checkers, even a stupid one like
this, tend to warn about the same files.  And those files tend to be
ones that are badly maintained, have often been bitrotting for some
years and could use some work.  Even better, they are in such a bad
shape that it's hard not to improve things.

For example, I once found something like the below in drivers/cdrom/:

#define FOO()	\
	bar();	\
	bar();	\
	bar();	\
	bar();

...

	if (baz)
		FOO();

So after macro extention, three of the four statements are always
executed and only one is conditional.  Since I didn't have hardware to
test things I didn't change the code.  My guess is the code still exists
unchanged.

Jörn

-- 
All models are wrong. Some models are useful.
-- George Box

Re: I am a volunteer

[Stefan Richter]

Willy Tarreau wrote:
> On Sun, May 25, 2008 at 08:23:22PM +0200, Davi Leal wrote:
>> Adrian Bunk wrote:
>> > The easiest and very valuable task is testing the kernel as described at
>> >   http://kernelnewbies.org/KernelTesters
>> 
>> I am more motivated to do development than testing.
> 
> And who do you think will test your dev then ?
> 
> Testing very quickly involves development because you will notice bugs
> first, then missing chunks of code to handle special conditions, and by
> this time you will feel much better with kernel internals and will have
> no problem starting on more complex tasks.
[...]

I second what Adrian and Willy wrote, because that's basically how I
became involved.  A driver subsystem which I wanted to use didn't work
quite 100%, so I always checked out the newest sources of the subsystem
development repo and reported open issues or regressions.  When (a)
developers vanished and (b) I became more confident I started to submit
patches myself.

Another conclusion from that is that you should pick an area which
genuinely interests you, i.e. a driver or protocol or whatever which you
actually use yourself frequently.  That's a lot more motivating than to
pick a project from a todo-list at random.
-- 
Stefan Richter
-=====-==--- -=-= ==-=-
http://arcgraph.de/sr/

Re: I am a volunteer

[Jesper Juhl]

2008/5/25 Davi Leal <davi@leals.com>:
> Hi,
>
> I would like to carry out some easy task, as realize a clean up replacing the
> use of one old function for another new one.
>
> I do not have any problem with C, Git, etc.
>
> Please, let me know what I can do.

Start by reading Documentation/HOWTO in the source (can be found
online here if you prefer:
http://lxr.linux.no/linux+v2.6.24.3/Documentation/HOWTO ).


-- 
Jesper Juhl <jesper.juhl@gmail.com>
Don't top-post http://www.catb.org/~esr/jargon/html/T/top-post.html
Plain text mails only, please http://www.expita.com/nomime.html

Re: I am a volunteer

[Davi Leal]

Jesper Juhl wrote:
> Davi Leal wrote:
> > I would like to carry out some easy task,
>
> Start by reading Documentation/HOWTO in the source (can be found
> online here if you prefer:
> http://lxr.linux.no/linux+v2.6.24.3/Documentation/HOWTO ).

I plan follow learning slowly. I have took note of all the advices.

Re: I am getting closer

[Davi Leal]

> > http://lxr.linux.no/linux+v2.6.24.3/Documentation/HOWTO ).

Very good link. Thanks  ;-)

Re: I am a volunteer

[Bartlomiej Zolnierkiewicz]

On Monday 26 May 2008, Jesper Juhl wrote:
> 2008/5/25 Davi Leal <davi@leals.com>:
> > Hi,
> >
> > I would like to carry out some easy task, as realize a clean up replacing the
> > use of one old function for another new one.
> >
> > I do not have any problem with C, Git, etc.
> >
> > Please, let me know what I can do.
> 
> Start by reading Documentation/HOWTO in the source (can be found
> online here if you prefer:
> http://lxr.linux.no/linux+v2.6.24.3/Documentation/HOWTO ).

Nah, nowadays every new kernel diver should start with:

"How to Dive with Sharks: a Primer" by Voltaire Cousteau 

http://www.mdaguam.com/divewithsharks.htm

;-)

Bart