RE: Exports for hrtimer APIs

RE: Exports for hrtimer APIs

[Stone, Joshua I]

Christoph Hellwig wrote:
> NACK.  We only add exports when they are a) sensible and b) are used
> in kernel.

It seems to me that SystemTap does present a sensible need to have
these exports.

> If you guys want to keep your code out of tree that's your problem.

I'm not sure what else you would suggest for this usage model.
SystemTap dynamically generates modules based on user scripts, so
this isn't something that can be added to the tree.

If SystemTap is to be able to make use of hrtimers, the only alternative
I see is to create our own APIs in the tree that wrap hrtimer, and then
export those.  This seems much less sensible than just exporting what is
already there...


Josh

Re: Exports for hrtimer APIs

[Adrian Bunk]

On Tue, Mar 14, 2006 at 01:15:52PM -0800, Stone, Joshua I wrote:
>...
> If SystemTap is to be able to make use of hrtimers, the only alternative
> I see is to create our own APIs in the tree that wrap hrtimer, and then
> export those.  This seems much less sensible than just exporting what is
> already there...

The question is if the exports you want to add to the kernel are 
acceptable or not.

If the answer would be "no", trying to threaten with this kind of cheap 
tricks is silly since the answer to your exported wrappers would be the 
same as for the direct exports.

> Josh

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: Exports for hrtimer APIs

[Stone, Joshua I]

Adrian Bunk wrote:
> The question is if the exports you want to add to the kernel are
> acceptable or not.
> 
> If the answer would be "no", trying to threaten with this kind of
> cheap tricks is silly since the answer to your exported wrappers
> would be the same as for the direct exports.

Sorry, I didn't mean to sound threatening...

My response was meant to address Christoph's implication that we
shouldn't be keeping SystemTap out of the kernel tree.  Due to the
nature of SystemTap, I don't see any way around this.

If it is decided that hrtimers are unacceptable for export, I'll respect
that decision.


Josh

Exports for hrtimer APIs

[Stone, Joshua I]

Hi,

I have noticed that the hrtimer APIs in 2.6.16 RCs are not exported, and
therefore modules are unable to use hrtimers.  I have not seen any
discussion on this point, so I presume that this is either an oversight,
or there has not been any case presented for exporting hrtimers.

I would like to add hrtimer support to SystemTap, which by design
requires the use of dynamically loaded kernel modules.  Can the
appropriate exports for hrtimers please be added?

Thanks,

Josh Stone


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Re: Exports for hrtimer APIs

[Andrew Morton]

"Stone, Joshua I" <joshua.i.stone@intel.com> wrote:
>
> Hi,
> 
> I have noticed that the hrtimer APIs in 2.6.16 RCs are not exported, and
> therefore modules are unable to use hrtimers.  I have not seen any
> discussion on this point, so I presume that this is either an oversight,
> or there has not been any case presented for exporting hrtimers.
> 
> I would like to add hrtimer support to SystemTap, which by design
> requires the use of dynamically loaded kernel modules.  Can the
> appropriate exports for hrtimers please be added?
> 

Please send a patch, so we can see what's needed.

EXPORT_SYMBOL_GPL would be preferred.

Re: Exports for hrtimer APIs

[Christoph Hellwig]

On Mon, Mar 13, 2006 at 02:00:16PM -0800, Stone, Joshua I wrote:
> Hi,
> 
> I have noticed that the hrtimer APIs in 2.6.16 RCs are not exported, and
> therefore modules are unable to use hrtimers.  I have not seen any
> discussion on this point, so I presume that this is either an oversight,
> or there has not been any case presented for exporting hrtimers.
> 
> I would like to add hrtimer support to SystemTap, which by design
> requires the use of dynamically loaded kernel modules.  Can the
> appropriate exports for hrtimers please be added?

NACK.  We only add exports when they are a) sensible and b) are used in
kernel.

If you guys want to keep your code out of tree that's your problem.