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* Exports for hrtimer APIs
@ 2006-03-13 22:00 Stone, Joshua I
  2006-03-14  6:50 ` Andrew Morton
  2006-03-14 15:29 ` Christoph Hellwig
  0 siblings, 2 replies; 6+ messages in thread
From: Stone, Joshua I @ 2006-03-13 22:00 UTC (permalink / raw)
  To: LKML

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


- Please CC me in any discussion on this, as I am not subscribed to LKML

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: Exports for hrtimer APIs
  2006-03-13 22:00 Stone, Joshua I
@ 2006-03-14  6:50 ` Andrew Morton
  2006-03-14 15:29 ` Christoph Hellwig
  1 sibling, 0 replies; 6+ messages in thread
From: Andrew Morton @ 2006-03-14  6:50 UTC (permalink / raw)
  To: Stone, Joshua I; +Cc: linux-kernel

"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.

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: Exports for hrtimer APIs
  2006-03-13 22:00 Stone, Joshua I
  2006-03-14  6:50 ` Andrew Morton
@ 2006-03-14 15:29 ` Christoph Hellwig
  1 sibling, 0 replies; 6+ messages in thread
From: Christoph Hellwig @ 2006-03-14 15:29 UTC (permalink / raw)
  To: Stone, Joshua I; +Cc: LKML

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.

^ permalink raw reply	[flat|nested] 6+ messages in thread

* RE: Exports for hrtimer APIs
@ 2006-03-14 21:15 Stone, Joshua I
  2006-03-14 21:31 ` Adrian Bunk
  0 siblings, 1 reply; 6+ messages in thread
From: Stone, Joshua I @ 2006-03-14 21:15 UTC (permalink / raw)
  To: Christoph Hellwig; +Cc: LKML

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

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: Exports for hrtimer APIs
  2006-03-14 21:15 Exports for hrtimer APIs Stone, Joshua I
@ 2006-03-14 21:31 ` Adrian Bunk
  0 siblings, 0 replies; 6+ messages in thread
From: Adrian Bunk @ 2006-03-14 21:31 UTC (permalink / raw)
  To: Stone, Joshua I; +Cc: Christoph Hellwig, LKML

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


^ permalink raw reply	[flat|nested] 6+ messages in thread

* RE: Exports for hrtimer APIs
@ 2006-03-14 21:48 Stone, Joshua I
  0 siblings, 0 replies; 6+ messages in thread
From: Stone, Joshua I @ 2006-03-14 21:48 UTC (permalink / raw)
  To: Adrian Bunk; +Cc: Christoph Hellwig, LKML

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

^ permalink raw reply	[flat|nested] 6+ messages in thread

end of thread, other threads:[~2006-03-14 21:49 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2006-03-14 21:15 Exports for hrtimer APIs Stone, Joshua I
2006-03-14 21:31 ` Adrian Bunk
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2006-03-14 21:48 Stone, Joshua I
2006-03-13 22:00 Stone, Joshua I
2006-03-14  6:50 ` Andrew Morton
2006-03-14 15:29 ` Christoph Hellwig

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