* how to link to hrtimers in the kernel
@ 2008-10-06 15:41 George Nychis
2008-10-06 16:33 ` [patch] " Randy.Dunlap
0 siblings, 1 reply; 5+ messages in thread
From: George Nychis @ 2008-10-06 15:41 UTC (permalink / raw)
To: linux-kernel
Hi all,
I have modified drivers/usb/core/devio.c to use hrtimer_nanosleep(), and
have included linux/hrtimer.h with it.
But now I am having trouble linking, I get:
ERROR: "hrtimer_nanosleep" [drivers/usb/core/usbcore.ko] undefined!
How do I properly link to the hrtimer library?
Thanks!
George
^ permalink raw reply [flat|nested] 5+ messages in thread
* [patch] Re: how to link to hrtimers in the kernel
2008-10-06 15:41 how to link to hrtimers in the kernel George Nychis
@ 2008-10-06 16:33 ` Randy.Dunlap
2008-10-06 16:51 ` Thomas Gleixner
0 siblings, 1 reply; 5+ messages in thread
From: Randy.Dunlap @ 2008-10-06 16:33 UTC (permalink / raw)
To: George Nychis; +Cc: linux-kernel, tglx
On Mon, 6 Oct 2008, George Nychis wrote:
> Hi all,
>
> I have modified drivers/usb/core/devio.c to use hrtimer_nanosleep(), and have
> included linux/hrtimer.h with it.
>
> But now I am having trouble linking, I get:
> ERROR: "hrtimer_nanosleep" [drivers/usb/core/usbcore.ko] undefined!
>
> How do I properly link to the hrtimer library?
Hi,
That function needs to be exported in its source file.
Patch below should fix it for you.
From: Randy Dunlap <randy.dunlap@oracle.com>
Export hrtimer_nanosleep() for module use.
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
---
kernel/hrtimer.c | 1 +
1 file changed, 1 insertion(+)
--- linux-2.6.27-rc8-git5.orig/kernel/hrtimer.c
+++ linux-2.6.27-rc8-git5/kernel/hrtimer.c
@@ -1559,6 +1559,7 @@ out:
destroy_hrtimer_on_stack(&t.timer);
return ret;
}
+EXPORT_SYMBOL_GPL(hrtimer_nanosleep);
asmlinkage long
sys_nanosleep(struct timespec __user *rqtp, struct timespec __user *rmtp)
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [patch] Re: how to link to hrtimers in the kernel
2008-10-06 16:33 ` [patch] " Randy.Dunlap
@ 2008-10-06 16:51 ` Thomas Gleixner
2008-10-06 17:16 ` George Nychis
0 siblings, 1 reply; 5+ messages in thread
From: Thomas Gleixner @ 2008-10-06 16:51 UTC (permalink / raw)
To: Randy.Dunlap; +Cc: George Nychis, linux-kernel
On Mon, 6 Oct 2008, Randy.Dunlap wrote:
> On Mon, 6 Oct 2008, George Nychis wrote:
>
> > Hi all,
> >
> > I have modified drivers/usb/core/devio.c to use hrtimer_nanosleep(), and have
> > included linux/hrtimer.h with it.
Please do not use hrtimer_nanosleep() in drivers. That's
wrong.
What do you want to achieve ?
> Export hrtimer_nanosleep() for module use.
NAK, hrtimer_nanosleep is part of the user space interfaces.
> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
> ---
> kernel/hrtimer.c | 1 +
> 1 file changed, 1 insertion(+)
>
> --- linux-2.6.27-rc8-git5.orig/kernel/hrtimer.c
> +++ linux-2.6.27-rc8-git5/kernel/hrtimer.c
> @@ -1559,6 +1559,7 @@ out:
> destroy_hrtimer_on_stack(&t.timer);
> return ret;
> }
> +EXPORT_SYMBOL_GPL(hrtimer_nanosleep);
>
> asmlinkage long
> sys_nanosleep(struct timespec __user *rqtp, struct timespec __user *rmtp)
>
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [patch] Re: how to link to hrtimers in the kernel
2008-10-06 16:51 ` Thomas Gleixner
@ 2008-10-06 17:16 ` George Nychis
2008-10-07 14:55 ` Brian Pomerantz
0 siblings, 1 reply; 5+ messages in thread
From: George Nychis @ 2008-10-06 17:16 UTC (permalink / raw)
To: Thomas Gleixner; +Cc: Randy.Dunlap, linux-kernel
Thomas Gleixner wrote:
> On Mon, 6 Oct 2008, Randy.Dunlap wrote:
>> On Mon, 6 Oct 2008, George Nychis wrote:
>>
>>> Hi all,
>>>
>>> I have modified drivers/usb/core/devio.c to use hrtimer_nanosleep(), and have
>>> included linux/hrtimer.h with it.
>
> Please do not use hrtimer_nanosleep() in drivers. That's
> wrong.
>
> What do you want to achieve ?
>
I am trying to sleep at the microsecond level, which ssleep and msleep
cannot provide. I couldn't find any other nanosleep method in the kernel.
I found information by searching the net on using jiffies to accomplish
sleep periods, but that is not high enough in resolution.
I'd greatly appreciate any feedback.
Thanks!
George
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [patch] Re: how to link to hrtimers in the kernel
2008-10-06 17:16 ` George Nychis
@ 2008-10-07 14:55 ` Brian Pomerantz
0 siblings, 0 replies; 5+ messages in thread
From: Brian Pomerantz @ 2008-10-07 14:55 UTC (permalink / raw)
To: George Nychis; +Cc: Thomas Gleixner, Randy.Dunlap, linux-kernel
On Mon, Oct 06, 2008 at 01:16:15PM -0400, George Nychis wrote:
>
> I am trying to sleep at the microsecond level, which ssleep and msleep
> cannot provide. I couldn't find any other nanosleep method in the kernel.
>
> I found information by searching the net on using jiffies to accomplish
> sleep periods, but that is not high enough in resolution.
>
> I'd greatly appreciate any feedback.
>
Is there any reason you can't use udelay()/ndelay()?
BAPper
^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2008-10-07 15:04 UTC | newest]
Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
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2008-10-06 15:41 how to link to hrtimers in the kernel George Nychis
2008-10-06 16:33 ` [patch] " Randy.Dunlap
2008-10-06 16:51 ` Thomas Gleixner
2008-10-06 17:16 ` George Nychis
2008-10-07 14:55 ` Brian Pomerantz
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