Re: Conditionals for development tests and output

[Sam Ravnborg <sam@ravnborg.org>]

On Fri, Jun 01, 2007 at 09:17:53PM -0700, Christoph Lameter wrote:
> This introduces 
> 
> CONFIG_DEVELKERNEL
> 
> If CONFIG_DEVELKERNEL is set then this is a development kernel.
> Otherwise the kernel to be built is a a production kernel.

The below patch suffers from the problem that changing the
value of DEVELKERNEL in the Makefile are not automatically
reflected in autoconf.h.
We need to get this fixed before merging this I think.

I have looked a bit on the kconfig stuff but so far
I did not find a good way to do so.

I hope Roman Zippel can come up with something - yes?

	Sam

[Kept rest of mail on purpose]
> 
> 
> If CONFIG_DEVELKERNEL is set then the constant
> 
> DEVELKERNEL
> 
> is set to 1. Otherwise it is zero.
> 
> The following functions are defined in kernel.h for diagnostics
> 
> DEVEL_WARN_ON(condition)
> 
> 	Warn on the condition but only if this is a development kernel
> 
> DEVEL_WARN_ON_ONCE(condition)
> 
> 	Warn on the condition once but only if this is a development kernel
> 
> devel_printk(fmt, ...)
> 
> 	Output that should only be generated for a development kernel.
> 
> 
> CONFIG_DEVELKERNEL is set and cleared by edit the Makefile. Line 7 contains
> 
> DEVELKERNEL = 1
> 
> 
> Updates SLAB and SLUB to not perform the kmalloc(0) tests anymore
> if the kernel is not a development kernel.
> 
> 
> Editing DEVELKERNEL requires a 
> 
> 	make clean
> 
> to correctly rebuild the kernel with the proper settings. This is similar 
> to editing the version number. Sam: Is there any way to avoid the make 
> clean?
> 
> Cc: Dave Jones <davej@redhat.com>
> Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
> Signed-off-by: Andrew Morton <akpm@linux-foundation.com>
> Signed-off-by: Christoph Lameter <clameter@sgi.com>
> 
> 
> ---
>  Makefile                 |    3 ++-
>  include/linux/kernel.h   |   14 ++++++++++++++
>  include/linux/slub_def.h |    2 +-
>  mm/slab.c                |    2 +-
>  mm/slub.c                |    4 ++--
>  scripts/kconfig/symbol.c |    9 +++++++++
>  6 files changed, 29 insertions(+), 5 deletions(-)
> 
> Index: slub/Makefile
> ===================================================================
> --- slub.orig/Makefile	2007-06-01 20:11:57.000000000 -0700
> +++ slub/Makefile	2007-06-01 20:56:27.000000000 -0700
> @@ -3,6 +3,7 @@ PATCHLEVEL = 6
>  SUBLEVEL = 22
>  EXTRAVERSION = -rc3-mm1
>  NAME = Jeff Thinks I Should Change This, But To What?
> +DEVELKERNEL = 1
>  
>  # *DOCUMENTATION*
>  # To see a list of typical targets execute "make help"
> @@ -320,7 +321,7 @@ AFLAGS          := -D__ASSEMBLY__
>  KERNELRELEASE = $(shell cat include/config/kernel.release 2> /dev/null)
>  KERNELVERSION = $(VERSION).$(PATCHLEVEL).$(SUBLEVEL)$(EXTRAVERSION)
>  
> -export VERSION PATCHLEVEL SUBLEVEL KERNELRELEASE KERNELVERSION
> +export VERSION PATCHLEVEL SUBLEVEL KERNELRELEASE KERNELVERSION DEVELKERNEL
>  export ARCH CONFIG_SHELL HOSTCC HOSTCFLAGS CROSS_COMPILE AS LD CC
>  export CPP AR NM STRIP OBJCOPY OBJDUMP MAKE AWK GENKSYMS PERL UTS_MACHINE
>  export HOSTCXX HOSTCXXFLAGS LDFLAGS_MODULE CHECK CHECKFLAGS
> Index: slub/scripts/kconfig/symbol.c
> ===================================================================
> --- slub.orig/scripts/kconfig/symbol.c	2007-06-01 20:13:24.000000000 -0700
> +++ slub/scripts/kconfig/symbol.c	2007-06-01 21:07:52.000000000 -0700
> @@ -72,6 +72,15 @@ void sym_init(void)
>  	sym->type = S_STRING;
>  	sym->flags |= SYMBOL_AUTO;
>  	sym_add_default(sym, uts.release);
> +
> +	sym = sym_lookup("DEVELKERNEL", 0);
> +	sym->type = S_BOOLEAN;
> +	sym->flags |= SYMBOL_VALID|SYMBOL_AUTO;
> +	p = getenv("DEVELKERNEL");
> +	if (p && atoi(p))
> +		sym_add_default(sym, "y");
> +	else
> +		sym_add_default(sym, "n");
>  }
>  
>  enum symbol_type sym_get_type(struct symbol *sym)
> Index: slub/include/linux/kernel.h
> ===================================================================
> --- slub.orig/include/linux/kernel.h	2007-06-01 20:19:17.000000000 -0700
> +++ slub/include/linux/kernel.h	2007-06-01 20:30:16.000000000 -0700
> @@ -375,4 +375,18 @@ struct sysinfo {
>  #define NUMA_BUILD 0
>  #endif
>  
> +#ifdef CONFIG_DEVELKERNEL
> +#define DEVELKERNEL 1
> +#else
> +#define DEVELKERNEL 0
> +#endif
> +
> +#define DEVEL_WARN_ON(x)	WARN_ON(DEVELKERNEL && (x))
> +#define DEVEL_WARN_ON_ONCE(x)	WARN_ON_ONCE(DEVELKERNEL && (x))
> +
> +#define devel_printk(fmt,arg...) 	({					\
> +	if (DEVELKERNEL)						\
> +			printk(fmt, ##arg);				\
> +})
> +
>  #endif
> Index: slub/include/linux/slub_def.h
> ===================================================================
> --- slub.orig/include/linux/slub_def.h	2007-06-01 20:25:06.000000000 -0700
> +++ slub/include/linux/slub_def.h	2007-06-01 20:28:02.000000000 -0700
> @@ -80,7 +80,7 @@ static inline int kmalloc_index(size_t s
>  	 * allocate memory but return ZERO_SIZE_PTR.
>  	 * WARN so that people can review and fix their code.
>  	 */
> -	WARN_ON_ONCE(size == 0);
> +	DEVEL_WARN_ON_ONCE(size == 0);
>  
>  	if (!size)
>  		return 0;
> Index: slub/mm/slub.c
> ===================================================================
> --- slub.orig/mm/slub.c	2007-06-01 20:24:26.000000000 -0700
> +++ slub/mm/slub.c	2007-06-01 20:28:20.000000000 -0700
> @@ -2525,8 +2525,8 @@ void __init kmem_cache_init(void)
>  	kmem_size = offsetof(struct kmem_cache, cpu_slab) +
>  				nr_cpu_ids * sizeof(struct page *);
>  
> -	printk(KERN_INFO "SLUB: Genslabs=%d, HWalign=%d, Order=%d-%d, MinObjects=%d,"
> -		" Processors=%d, Nodes=%d\n",
> +	devel_printk(KERN_INFO "SLUB: Genslabs=%d, HWalign=%d, Order=%d-%d, "
> +		"MinObjects=%d, Processors=%d, Nodes=%d\n",
>  		KMALLOC_SHIFT_HIGH, cache_line_size(),
>  		slub_min_order, slub_max_order, slub_min_objects,
>  		nr_cpu_ids, nr_node_ids);
> Index: slub/mm/slab.c
> ===================================================================
> --- slub.orig/mm/slab.c	2007-06-01 20:29:39.000000000 -0700
> +++ slub/mm/slab.c	2007-06-01 20:29:45.000000000 -0700
> @@ -774,7 +774,7 @@ static inline struct kmem_cache *__find_
>  	 */
>  	BUG_ON(malloc_sizes[INDEX_AC].cs_cachep == NULL);
>  #endif
> -	WARN_ON_ONCE(size == 0);
> +	DEVEL_WARN_ON_ONCE(size == 0);
>  	while (size > csizep->cs_size)
>  		csizep++;
>