Compilation of pktgen fails for ARCH=um

Compilation of pktgen fails for ARCH=um

[Christoph Paasch]

Hi,

compiling the packet generator (NET_PKTGEN) for ARCH=um does not work.

Since commit 43d28b6515a6ea580a198df3e253e88236f08978 (pktgen: increasing 
transmission granularity), function spin(...) uses ndelay(...), which is not 
implemented for uml.

Should pktgen be disabled for uml?
Or should ndelay be an empty macro? (in arch/um/include/asm/delay.h)

Regards,
Christoph

--
Christoph Paasch

Research Assistant
IP Networking Lab --- http://inl.info.ucl.ac.be
MultiPath TCP in the Linux Kernel --- http://inl.info.ucl.ac.be/mptcp
Université Catholique de Louvain

www.rollerbulls.be
--

[PATCH/RFC] Re: Compilation of pktgen fails for ARCH=um

[Randy Dunlap]

On Thu, 30 Dec 2010 11:33:14 +0100 Christoph Paasch wrote:

> Hi,
> 
> compiling the packet generator (NET_PKTGEN) for ARCH=um does not work.
> 
> Since commit 43d28b6515a6ea580a198df3e253e88236f08978 (pktgen: increasing 
> transmission granularity), function spin(...) uses ndelay(...), which is not 
> implemented for uml.
> 
> Should pktgen be disabled for uml?
> Or should ndelay be an empty macro? (in arch/um/include/asm/delay.h)

or ndelay() in arch/um/include/asm/delay.y can be removed completely
and then the default implementation of ndelay() will be used from
include/linux/delay.h.
This builds cleanly, but I don't know how well it would work.

---
From: Randy Dunlap <randy.dunlap@oracle.com>

Allow uml to use the default implementation of ndelay() from
<linux/delay.h>.  Fixes build error:

net/built-in.o: In function `spin':
pktgen.c:(.text+0x27391): undefined reference to `__unimplemented_ndelay'

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
---
 arch/um/include/asm/delay.h |    5 -----
 1 file changed, 5 deletions(-)

--- linux-next-20101214.orig/arch/um/include/asm/delay.h
+++ linux-next-20101214/arch/um/include/asm/delay.h
@@ -12,9 +12,4 @@ extern void __delay(unsigned long loops)
 #define udelay(n) ((__builtin_constant_p(n) && (n) > 20000) ? \
 	__bad_udelay() : __udelay(n))
 
-/* It appears that ndelay is not used at all for UML, and has never been
- * implemented. */
-extern void __unimplemented_ndelay(void);
-#define ndelay(n) __unimplemented_ndelay()
-
 #endif

Re: [PATCH/RFC] Re: Compilation of pktgen fails for ARCH=um

[Christoph Paasch]

Hi,

On Thursday, December 30, 2010 wrote Randy Dunlap:
> or ndelay() in arch/um/include/asm/delay.y can be removed completely
> and then the default implementation of ndelay() will be used from
> include/linux/delay.h.
> This builds cleanly, but I don't know how well it would work.
This will do a rounded up micro-second sleep. I think that it's ok.

Christoph

> ---
> From: Randy Dunlap <randy.dunlap@oracle.com>
> 
> Allow uml to use the default implementation of ndelay() from
> <linux/delay.h>.  Fixes build error:
> 
> net/built-in.o: In function `spin':
> pktgen.c:(.text+0x27391): undefined reference to `__unimplemented_ndelay'
> 
> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
> ---
>  arch/um/include/asm/delay.h |    5 -----
>  1 file changed, 5 deletions(-)
> 
> --- linux-next-20101214.orig/arch/um/include/asm/delay.h
> +++ linux-next-20101214/arch/um/include/asm/delay.h
> @@ -12,9 +12,4 @@ extern void __delay(unsigned long loops)
>  #define udelay(n) ((__builtin_constant_p(n) && (n) > 20000) ? \
>  	__bad_udelay() : __udelay(n))
> 
> -/* It appears that ndelay is not used at all for UML, and has never been
> - * implemented. */
> -extern void __unimplemented_ndelay(void);
> -#define ndelay(n) __unimplemented_ndelay()
> -
>  #endif

--
Christoph Paasch
PhD Student

IP Networking Lab --- http://inl.info.ucl.ac.be
MultiPath TCP in the Linux Kernel --- http://inl.info.ucl.ac.be/mptcp
Université Catholique de Louvain

www.rollerbulls.be
--