svn commit: r254164 - head/sys/arm/include

[Alan Cox]

On Aug 9, 2013, at 2:53 PM, Olivier Houchard wrote:

> Author: cognet
> Date: Fri Aug  9 21:53:02 2013
> New Revision: 254164
> URL: http://svnweb.freebsd.org/changeset/base/254164
> 
> Log:
>  Make sure vm_kmem_size is aligned on a page boundary, since that's what vmem
>  expects.
> 
> Modified:
>  head/sys/arm/include/vmparam.h
> 
> Modified: head/sys/arm/include/vmparam.h
> ==============================================================================
> --- head/sys/arm/include/vmparam.h	Fri Aug  9 21:14:55 2013	(r254163)
> +++ head/sys/arm/include/vmparam.h	Fri Aug  9 21:53:02 2013	(r254164)
> @@ -165,8 +165,8 @@
>  * Ceiling on the size of the kmem submap: 40% of the kernel map.
>  */
> #ifndef VM_KMEM_SIZE_MAX
> -#define	VM_KMEM_SIZE_MAX	((vm_max_kernel_address - \
> -    VM_MIN_KERNEL_ADDRESS + 1) * 2 / 5)
> +#define	VM_KMEM_SIZE_MAX	(((vm_max_kernel_address - \
> +    VM_MIN_KERNEL_ADDRESS + 1) * 2 / 5) &~ PAGE_MASK)
> #endif
> 
> #ifdef ARM_USE_SMALL_ALLOC
> 


I would suggest a different approach.  Add a round_page() to kmeminit() after the TUNABLE_ULONG_FETCH("vm.kmem_size", ...).  This alternate approach has two virtues.  First, it will also handle a /boot/loader.conf value that isn't page aligned.  Second, it will simultaneously address the same problem on other architectures.

Thanks,
Alan