next-0402: build fails at mm/debug-pagealloc.c

next-0402: build fails at mm/debug-pagealloc.c

[Alexander Beregalov]

mm/debug-pagealloc.c: In function 'set_page_poison':
mm/debug-pagealloc.c:8: error: 'struct page' has no member named 'debug_flags'
mm/debug-pagealloc.c: In function 'clear_page_poison':
mm/debug-pagealloc.c:13: error: 'struct page' has no member named 'debug_flags'
mm/debug-pagealloc.c: In function 'page_poison':
mm/debug-pagealloc.c:18: error: 'struct page' has no member named 'debug_flags'
mm/debug-pagealloc.c: At top level:
mm/debug-pagealloc.c:120: error: redefinition of 'kernel_map_pages'
include/linux/mm.h:1278: error: previous definition of
'kernel_map_pages' was here
mm/debug-pagealloc.c: In function 'kernel_map_pages':
mm/debug-pagealloc.c:122: error: 'debug_pagealloc_enabled' undeclared
(first use in this function)

Should debug_flags really be in vm_area_struct instead of `struct page` ?

[PATCH] build fix for generic debug pagealloc

[Akinobu Mita]

> mm/debug-pagealloc.c: In function 'set_page_poison':
> mm/debug-pagealloc.c:8: error: 'struct page' has no member named 'debug_flags'
> mm/debug-pagealloc.c: In function 'clear_page_poison':
> mm/debug-pagealloc.c:13: error: 'struct page' has no member named 'debug_flags'
> mm/debug-pagealloc.c: In function 'page_poison':
> mm/debug-pagealloc.c:18: error: 'struct page' has no member named 'debug_flags'
> mm/debug-pagealloc.c: At top level:
> mm/debug-pagealloc.c:120: error: redefinition of 'kernel_map_pages'
> include/linux/mm.h:1278: error: previous definition of
> 'kernel_map_pages' was here
> mm/debug-pagealloc.c: In function 'kernel_map_pages':
> mm/debug-pagealloc.c:122: error: 'debug_pagealloc_enabled' undeclared
> (first use in this function)

This patch fixes build failure with generic debug pagealloc:

 - debug_flags should be in struct page
 - define DEBUG_PAGEALLOC config option for all architectures

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Reported-by: Alexander Beregalov <a.beregalov@gmail.com>
---
 arch/powerpc/Kconfig.debug |   10 ----------
 arch/s390/Kconfig.debug    |    9 ---------
 arch/sparc/Kconfig.debug   |    9 ---------
 arch/x86/Kconfig.debug     |    9 ---------
 include/linux/mm_types.h   |    6 +++---
 mm/Kconfig.debug           |    9 +++++++++
 6 files changed, 12 insertions(+), 40 deletions(-)

diff --git a/arch/powerpc/Kconfig.debug b/arch/powerpc/Kconfig.debug
index 6aa0b5e..a1098e2 100644
--- a/arch/powerpc/Kconfig.debug
+++ b/arch/powerpc/Kconfig.debug
@@ -27,16 +27,6 @@ config DEBUG_STACK_USAGE
 
 	  This option will slow down process creation somewhat.
 
-config DEBUG_PAGEALLOC
-        bool "Debug page memory allocations"
-        depends on DEBUG_KERNEL && !HIBERNATION
-	depends on ARCH_SUPPORTS_DEBUG_PAGEALLOC
-        help
-          Unmap pages from the kernel linear mapping after free_pages().
-          This results in a large slowdown, but helps to find certain types
-          of memory corruptions.
-
-
 config HCALL_STATS
 	bool "Hypervisor call instrumentation"
 	depends on PPC_PSERIES && DEBUG_FS
diff --git a/arch/s390/Kconfig.debug b/arch/s390/Kconfig.debug
index 7e297a3..2283933 100644
--- a/arch/s390/Kconfig.debug
+++ b/arch/s390/Kconfig.debug
@@ -6,13 +6,4 @@ config TRACE_IRQFLAGS_SUPPORT
 
 source "lib/Kconfig.debug"
 
-config DEBUG_PAGEALLOC
-	bool "Debug page memory allocations"
-	depends on DEBUG_KERNEL
-	depends on ARCH_SUPPORTS_DEBUG_PAGEALLOC
-	help
-	  Unmap pages from the kernel linear mapping after free_pages().
-	  This results in a slowdown, but helps to find certain types of
-	  memory corruptions.
-
 endmenu
diff --git a/arch/sparc/Kconfig.debug b/arch/sparc/Kconfig.debug
index d001b42..90d5fe2 100644
--- a/arch/sparc/Kconfig.debug
+++ b/arch/sparc/Kconfig.debug
@@ -22,15 +22,6 @@ config DEBUG_DCFLUSH
 config STACK_DEBUG
 	bool "Stack Overflow Detection Support"
 
-config DEBUG_PAGEALLOC
-	bool "Debug page memory allocations"
-	depends on DEBUG_KERNEL && !HIBERNATION
-	depends on ARCH_SUPPORTS_DEBUG_PAGEALLOC
-	help
-	  Unmap pages from the kernel linear mapping after free_pages().
-	  This results in a large slowdown, but helps to find certain types
-	  of memory corruptions.
-
 config MCOUNT
 	bool
 	depends on SPARC64
diff --git a/arch/x86/Kconfig.debug b/arch/x86/Kconfig.debug
index a345cb5..d8359e7 100644
--- a/arch/x86/Kconfig.debug
+++ b/arch/x86/Kconfig.debug
@@ -72,15 +72,6 @@ config DEBUG_STACK_USAGE
 
 	  This option will slow down process creation somewhat.
 
-config DEBUG_PAGEALLOC
-	bool "Debug page memory allocations"
-	depends on DEBUG_KERNEL
-	depends on ARCH_SUPPORTS_DEBUG_PAGEALLOC
-	---help---
-	  Unmap pages from the kernel linear mapping after free_pages().
-	  This results in a large slowdown, but helps to find certain types
-	  of memory corruptions.
-
 config DEBUG_PER_CPU_MAPS
 	bool "Debug access to per_cpu maps"
 	depends on DEBUG_KERNEL
diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h
index ddadb4d..0e80e26 100644
--- a/include/linux/mm_types.h
+++ b/include/linux/mm_types.h
@@ -95,6 +95,9 @@ struct page {
 	void *virtual;			/* Kernel virtual address (NULL if
 					   not kmapped, ie. highmem) */
 #endif /* WANT_PAGE_VIRTUAL */
+#ifdef CONFIG_WANT_PAGE_DEBUG_FLAGS
+	unsigned long debug_flags;	/* Use atomic bitops on this */
+#endif
 };
 
 /*
@@ -175,9 +178,6 @@ struct vm_area_struct {
 #ifdef CONFIG_NUMA
 	struct mempolicy *vm_policy;	/* NUMA policy for the VMA */
 #endif
-#ifdef CONFIG_WANT_PAGE_DEBUG_FLAGS
-	unsigned long debug_flags;	/* Use atomic bitops on this */
-#endif
 };
 
 struct core_thread {
diff --git a/mm/Kconfig.debug b/mm/Kconfig.debug
index c8d62d4..bb01e29 100644
--- a/mm/Kconfig.debug
+++ b/mm/Kconfig.debug
@@ -1,3 +1,12 @@
+config DEBUG_PAGEALLOC
+	bool "Debug page memory allocations"
+	depends on DEBUG_KERNEL && ARCH_SUPPORTS_DEBUG_PAGEALLOC
+	depends on !HIBERNATION || !PPC && !SPARC
+	---help---
+	  Unmap pages from the kernel linear mapping after free_pages().
+	  This results in a large slowdown, but helps to find certain types
+	  of memory corruptions.
+
 config WANT_PAGE_DEBUG_FLAGS
 	bool
 

Re: [PATCH] build fix for generic debug pagealloc

[Andrew Morton]

On Fri, 3 Apr 2009 01:31:52 +0900 Akinobu Mita <akinobu.mita@gmail.com> wrote:

> > mm/debug-pagealloc.c: In function 'set_page_poison':
> > mm/debug-pagealloc.c:8: error: 'struct page' has no member named 'debug_flags'
> > mm/debug-pagealloc.c: In function 'clear_page_poison':
> > mm/debug-pagealloc.c:13: error: 'struct page' has no member named 'debug_flags'
> > mm/debug-pagealloc.c: In function 'page_poison':
> > mm/debug-pagealloc.c:18: error: 'struct page' has no member named 'debug_flags'
> > mm/debug-pagealloc.c: At top level:
> > mm/debug-pagealloc.c:120: error: redefinition of 'kernel_map_pages'
> > include/linux/mm.h:1278: error: previous definition of
> > 'kernel_map_pages' was here
> > mm/debug-pagealloc.c: In function 'kernel_map_pages':
> > mm/debug-pagealloc.c:122: error: 'debug_pagealloc_enabled' undeclared
> > (first use in this function)
> 
> This patch fixes build failure with generic debug pagealloc:
> 
>  - debug_flags should be in struct page
>  - define DEBUG_PAGEALLOC config option for all architectures
>
> ...
>
>  	bool "Debug access to per_cpu maps"
>  	depends on DEBUG_KERNEL
> diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h
> index ddadb4d..0e80e26 100644
> --- a/include/linux/mm_types.h
> +++ b/include/linux/mm_types.h
> @@ -95,6 +95,9 @@ struct page {
>  	void *virtual;			/* Kernel virtual address (NULL if
>  					   not kmapped, ie. highmem) */
>  #endif /* WANT_PAGE_VIRTUAL */
> +#ifdef CONFIG_WANT_PAGE_DEBUG_FLAGS
> +	unsigned long debug_flags;	/* Use atomic bitops on this */
> +#endif
>  };
>  
>  /*
> @@ -175,9 +178,6 @@ struct vm_area_struct {
>  #ifdef CONFIG_NUMA
>  	struct mempolicy *vm_policy;	/* NUMA policy for the VMA */
>  #endif
> -#ifdef CONFIG_WANT_PAGE_DEBUG_FLAGS
> -	unsigned long debug_flags;	/* Use atomic bitops on this */
> -#endif
>  };

dammit.

>  struct core_thread {
> diff --git a/mm/Kconfig.debug b/mm/Kconfig.debug
> index c8d62d4..bb01e29 100644
> --- a/mm/Kconfig.debug
> +++ b/mm/Kconfig.debug
> @@ -1,3 +1,12 @@
> +config DEBUG_PAGEALLOC
> +	bool "Debug page memory allocations"
> +	depends on DEBUG_KERNEL && ARCH_SUPPORTS_DEBUG_PAGEALLOC
> +	depends on !HIBERNATION || !PPC && !SPARC
> +	---help---
> +	  Unmap pages from the kernel linear mapping after free_pages().
> +	  This results in a large slowdown, but helps to find certain types
> +	  of memory corruptions.
> +

I guess this is why it wasn't discovered in my compile testing.  It's
quite regrettable that `make allmodconfig' didn't enable the feature. 
That's what allmodconfig is for.

Re: [PATCH] build fix for generic debug pagealloc

[Ingo Molnar]

* Andrew Morton <akpm@linux-foundation.org> wrote:

> > +config DEBUG_PAGEALLOC
> > +	bool "Debug page memory allocations"
> > +	depends on DEBUG_KERNEL && ARCH_SUPPORTS_DEBUG_PAGEALLOC
> > +	depends on !HIBERNATION || !PPC && !SPARC
> > +	---help---
> > +	  Unmap pages from the kernel linear mapping after free_pages().
> > +	  This results in a large slowdown, but helps to find certain types
> > +	  of memory corruptions.
> > +
> 
> I guess this is why it wasn't discovered in my compile testing.  
> It's quite regrettable that `make allmodconfig' didn't enable the 
> feature. That's what allmodconfig is for.

Hm, i _do_ remember some hibernation magic fix from Rafael, in the 
area of debugalloc. Many months ago.

Rafael, is it supposed to work? If yes, i think we should unblock 
it.

	Ingo

Re: [PATCH] build fix for generic debug pagealloc

[Rafael J. Wysocki]

On Friday 03 April 2009, Ingo Molnar wrote:
> 
> * Andrew Morton <akpm@linux-foundation.org> wrote:
> 
> > > +config DEBUG_PAGEALLOC
> > > +	bool "Debug page memory allocations"
> > > +	depends on DEBUG_KERNEL && ARCH_SUPPORTS_DEBUG_PAGEALLOC
> > > +	depends on !HIBERNATION || !PPC && !SPARC
> > > +	---help---
> > > +	  Unmap pages from the kernel linear mapping after free_pages().
> > > +	  This results in a large slowdown, but helps to find certain types
> > > +	  of memory corruptions.
> > > +
> > 
> > I guess this is why it wasn't discovered in my compile testing.  
> > It's quite regrettable that `make allmodconfig' didn't enable the 
> > feature. That's what allmodconfig is for.
> 
> Hm, i _do_ remember some hibernation magic fix from Rafael, in the 
> area of debugalloc. Many months ago.
> 
> Rafael, is it supposed to work? If yes, i think we should unblock 
> it.

Yes, it is, at least on x86.

ISTR using DEBUG_PAGEALLOC with hibernation quite some time ago already.

Thanks,
Rafael

Re: [PATCH] build fix for generic debug pagealloc

[Ingo Molnar]

* Rafael J. Wysocki <rjw@sisk.pl> wrote:

> On Friday 03 April 2009, Ingo Molnar wrote:
> > 
> > * Andrew Morton <akpm@linux-foundation.org> wrote:
> > 
> > > > +config DEBUG_PAGEALLOC
> > > > +	bool "Debug page memory allocations"
> > > > +	depends on DEBUG_KERNEL && ARCH_SUPPORTS_DEBUG_PAGEALLOC
> > > > +	depends on !HIBERNATION || !PPC && !SPARC
> > > > +	---help---
> > > > +	  Unmap pages from the kernel linear mapping after free_pages().
> > > > +	  This results in a large slowdown, but helps to find certain types
> > > > +	  of memory corruptions.
> > > > +
> > > 
> > > I guess this is why it wasn't discovered in my compile testing.  
> > > It's quite regrettable that `make allmodconfig' didn't enable the 
> > > feature. That's what allmodconfig is for.
> > 
> > Hm, i _do_ remember some hibernation magic fix from Rafael, in the 
> > area of debugalloc. Many months ago.
> > 
> > Rafael, is it supposed to work? If yes, i think we should unblock 
> > it.
> 
> Yes, it is, at least on x86.
> 
> ISTR using DEBUG_PAGEALLOC with hibernation quite some time ago 
> already.

Could you please send a patch to Andrew then to remove the above 
dependency?

	Ingo