Solve section mismatch for free_area_init_core.

Solve section mismatch for free_area_init_core.

[Alexander van Heukelum]

Solve section mismatch for free_area_init_core:

WARNING: vmlinux.o(.meminit.text+0x649): 
Section mismatch in reference from the 
function free_area_init_core() to the function .init.text:setup_usemap()
The function __meminit free_area_init_core() references
a function __init setup_usemap().
If free_area_init_core is only used by setup_usemap then
annotate free_area_init_core with a matching annotation.

The warning is covers this stack of functions in mm/page_alloc.c:

alloc_bootmem_node must be marked __init.
alloc_bootmem_node is used by setup_usemap, if !SPARSEMEM.
(usemap_size is only used by setup_usemap, if !SPARSEMEM.)
setup_usemap is only used by free_area_init_core.
free_area_init_core is only used by free_area_init_node.

free_area_init_node is used by:
arch/alpha/mm/numa.c: __init paging_init()
arch/arm/mm/init.c: __init bootmem_init_node()
arch/avr32/mm/init.c: __init paging_init()
arch/cris/arch-v10/mm/init.c: __init paging_init()
arch/cris/arch-v32/mm/init.c: __init paging_init()
arch/m32r/mm/discontig.c: __init zone_sizes_init()
arch/m32r/mm/init.c: __init zone_sizes_init()
arch/m68k/mm/motorola.c: __init paging_init()
arch/m68k/mm/sun3mmu.c: __init paging_init()
arch/mips/sgi-ip27/ip27-memory.c: __init paging_init()
arch/parisc/mm/init.c: __init paging_init()
arch/sparc/mm/srmmu.c: __init srmmu_paging_init()
arch/sparc/mm/sun4c.c: __init sun4c_paging_init()
arch/sparc64/mm/init.c: __init paging_init()
mm/page_alloc.c: __init free_area_init_nodes()
mm/page_alloc.c: __init free_area_init()
and
mm/memory_hotplug.c: hotadd_new_pgdat()

hotadd_new_pgdat can not be an __init function, but:

It is compiled for MEMORY_HOTPLUG configurations only
MEMORY_HOTPLUG depends on SPARSEMEM || X86_64_ACPI_NUMA
X86_64_ACPI_NUMA depends on X86_64
ARCH_FLATMEM_ENABLE depends on X86_32
ARCH_DISCONTIGMEM_ENABLE depends on X86_32
So X86_64_ACPI_NUMA implies SPARSEMEM, right?

So we can mark the stack of functions __init for !SPARSEMEM,
but we must mark them __meminit for SPARSEMEM configurations.
This is ok, because then the calls to alloc_bootmem_node are
also avoided.

Compile-tested on:
silly minimal config
defconfig x86_32
defconfig x86_64
defconfig x86_64 -HIBERNATION +MEMORY_HOTPLUG

Comments?

Signed-off-by: Alexander van Heukelum <heukelum@fastmail.fm>


diff --git a/mm/internal.h b/mm/internal.h
index 953f941..5b46b32 100644
--- a/mm/internal.h
+++ b/mm/internal.h
@@ -47,4 +47,17 @@ static inline unsigned long page_order(struct page *page)
 	VM_BUG_ON(!PageBuddy(page));
 	return page_private(page);
 }
+
+/*
+ * FLATMEM and DISCONTIGMEM configurations use alloc_bootmem_node,
+ * so all functions starting at paging_init should be marked __init
+ * in those cases. SPARSEMEM, however, allows for memory hotplug,
+ * and alloc_bootmem_node is not used.
+ */
+#ifdef CONFIG_SPARSEMEM
+#define __paginginit __meminit
+#else
+#define __paginginit __init
+#endif
+
 #endif
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index b2838c2..859be40 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -3321,7 +3321,7 @@ static inline int pageblock_default_order(unsigned int order)
  *   - mark all memory queues empty
  *   - clear the memory bitmaps
  */
-static void __meminit free_area_init_core(struct pglist_data *pgdat,
+static void __paginginit free_area_init_core(struct pglist_data *pgdat,
 		unsigned long *zones_size, unsigned long *zholes_size)
 {
 	enum zone_type j;
@@ -3445,7 +3445,7 @@ static void __init_refok alloc_node_mem_map(struct pglist_data *pgdat)
 #endif /* CONFIG_FLAT_NODE_MEM_MAP */
 }
 
-void __meminit free_area_init_node(int nid, struct pglist_data *pgdat,
+void __paginginit free_area_init_node(int nid, struct pglist_data *pgdat,
 		unsigned long *zones_size, unsigned long node_start_pfn,
 		unsigned long *zholes_size)
 {

Re: Solve section mismatch for free_area_init_core.

[Sam Ravnborg]

Hi Andrew.

I have (triggered by Geert) spend some time reviewing this patch
and I see no better way to fix it.

So it gets my:

Reviewed-by: Sam Ravnborg <sam@ravnborg.org>

Original mail is here:
http://lkml.org/lkml/2008/2/3/129

Can you take it in -mm so we get some testing coverage.

Thanks,
	Sam

On Sun, Feb 03, 2008 at 06:21:48PM +0100, Alexander van Heukelum wrote:
> Solve section mismatch for free_area_init_core:
> 
> WARNING: vmlinux.o(.meminit.text+0x649): 
> Section mismatch in reference from the 
> function free_area_init_core() to the function .init.text:setup_usemap()
> The function __meminit free_area_init_core() references
> a function __init setup_usemap().
> If free_area_init_core is only used by setup_usemap then
> annotate free_area_init_core with a matching annotation.
> 
> The warning is covers this stack of functions in mm/page_alloc.c:
> 
> alloc_bootmem_node must be marked __init.
> alloc_bootmem_node is used by setup_usemap, if !SPARSEMEM.
> (usemap_size is only used by setup_usemap, if !SPARSEMEM.)
> setup_usemap is only used by free_area_init_core.
> free_area_init_core is only used by free_area_init_node.
> 
> free_area_init_node is used by:
> arch/alpha/mm/numa.c: __init paging_init()
> arch/arm/mm/init.c: __init bootmem_init_node()
> arch/avr32/mm/init.c: __init paging_init()
> arch/cris/arch-v10/mm/init.c: __init paging_init()
> arch/cris/arch-v32/mm/init.c: __init paging_init()
> arch/m32r/mm/discontig.c: __init zone_sizes_init()
> arch/m32r/mm/init.c: __init zone_sizes_init()
> arch/m68k/mm/motorola.c: __init paging_init()
> arch/m68k/mm/sun3mmu.c: __init paging_init()
> arch/mips/sgi-ip27/ip27-memory.c: __init paging_init()
> arch/parisc/mm/init.c: __init paging_init()
> arch/sparc/mm/srmmu.c: __init srmmu_paging_init()
> arch/sparc/mm/sun4c.c: __init sun4c_paging_init()
> arch/sparc64/mm/init.c: __init paging_init()
> mm/page_alloc.c: __init free_area_init_nodes()
> mm/page_alloc.c: __init free_area_init()
> and
> mm/memory_hotplug.c: hotadd_new_pgdat()
> 
> hotadd_new_pgdat can not be an __init function, but:
> 
> It is compiled for MEMORY_HOTPLUG configurations only
> MEMORY_HOTPLUG depends on SPARSEMEM || X86_64_ACPI_NUMA
> X86_64_ACPI_NUMA depends on X86_64
> ARCH_FLATMEM_ENABLE depends on X86_32
> ARCH_DISCONTIGMEM_ENABLE depends on X86_32
> So X86_64_ACPI_NUMA implies SPARSEMEM, right?
> 
> So we can mark the stack of functions __init for !SPARSEMEM,
> but we must mark them __meminit for SPARSEMEM configurations.
> This is ok, because then the calls to alloc_bootmem_node are
> also avoided.
> 
> Compile-tested on:
> silly minimal config
> defconfig x86_32
> defconfig x86_64
> defconfig x86_64 -HIBERNATION +MEMORY_HOTPLUG
> 
> Comments?
> 
> Signed-off-by: Alexander van Heukelum <heukelum@fastmail.fm>
> 
> 
> diff --git a/mm/internal.h b/mm/internal.h
> index 953f941..5b46b32 100644
> --- a/mm/internal.h
> +++ b/mm/internal.h
> @@ -47,4 +47,17 @@ static inline unsigned long page_order(struct page *page)
>  	VM_BUG_ON(!PageBuddy(page));
>  	return page_private(page);
>  }
> +
> +/*
> + * FLATMEM and DISCONTIGMEM configurations use alloc_bootmem_node,
> + * so all functions starting at paging_init should be marked __init
> + * in those cases. SPARSEMEM, however, allows for memory hotplug,
> + * and alloc_bootmem_node is not used.
> + */
> +#ifdef CONFIG_SPARSEMEM
> +#define __paginginit __meminit
> +#else
> +#define __paginginit __init
> +#endif
> +
>  #endif
> diff --git a/mm/page_alloc.c b/mm/page_alloc.c
> index b2838c2..859be40 100644
> --- a/mm/page_alloc.c
> +++ b/mm/page_alloc.c
> @@ -3321,7 +3321,7 @@ static inline int pageblock_default_order(unsigned int order)
>   *   - mark all memory queues empty
>   *   - clear the memory bitmaps
>   */
> -static void __meminit free_area_init_core(struct pglist_data *pgdat,
> +static void __paginginit free_area_init_core(struct pglist_data *pgdat,
>  		unsigned long *zones_size, unsigned long *zholes_size)
>  {
>  	enum zone_type j;
> @@ -3445,7 +3445,7 @@ static void __init_refok alloc_node_mem_map(struct pglist_data *pgdat)
>  #endif /* CONFIG_FLAT_NODE_MEM_MAP */
>  }
>  
> -void __meminit free_area_init_node(int nid, struct pglist_data *pgdat,
> +void __paginginit free_area_init_node(int nid, struct pglist_data *pgdat,
>  		unsigned long *zones_size, unsigned long node_start_pfn,
>  		unsigned long *zholes_size)
>  {
> --
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at  http://www.tux.org/lkml/

Re: Solve section mismatch for free_area_init_core.

[Geert Uytterhoeven]

On Mon, 18 Feb 2008, Sam Ravnborg wrote:
> I have (triggered by Geert) spend some time reviewing this patch
> and I see no better way to fix it.
> 
> So it gets my:
> 
> Reviewed-by: Sam Ravnborg <sam@ravnborg.org>

Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>

> Original mail is here:
> http://lkml.org/lkml/2008/2/3/129
> 
> Can you take it in -mm so we get some testing coverage.
> 
> Thanks,
> 	Sam
> 
> On Sun, Feb 03, 2008 at 06:21:48PM +0100, Alexander van Heukelum wrote:
> > Solve section mismatch for free_area_init_core:
> > 
> > WARNING: vmlinux.o(.meminit.text+0x649): 
> > Section mismatch in reference from the 
> > function free_area_init_core() to the function .init.text:setup_usemap()
> > The function __meminit free_area_init_core() references
> > a function __init setup_usemap().
> > If free_area_init_core is only used by setup_usemap then
> > annotate free_area_init_core with a matching annotation.
> > 
> > The warning is covers this stack of functions in mm/page_alloc.c:
> > 
> > alloc_bootmem_node must be marked __init.
> > alloc_bootmem_node is used by setup_usemap, if !SPARSEMEM.
> > (usemap_size is only used by setup_usemap, if !SPARSEMEM.)
> > setup_usemap is only used by free_area_init_core.
> > free_area_init_core is only used by free_area_init_node.
> > 
> > free_area_init_node is used by:
> > arch/alpha/mm/numa.c: __init paging_init()
> > arch/arm/mm/init.c: __init bootmem_init_node()
> > arch/avr32/mm/init.c: __init paging_init()
> > arch/cris/arch-v10/mm/init.c: __init paging_init()
> > arch/cris/arch-v32/mm/init.c: __init paging_init()
> > arch/m32r/mm/discontig.c: __init zone_sizes_init()
> > arch/m32r/mm/init.c: __init zone_sizes_init()
> > arch/m68k/mm/motorola.c: __init paging_init()
> > arch/m68k/mm/sun3mmu.c: __init paging_init()
> > arch/mips/sgi-ip27/ip27-memory.c: __init paging_init()
> > arch/parisc/mm/init.c: __init paging_init()
> > arch/sparc/mm/srmmu.c: __init srmmu_paging_init()
> > arch/sparc/mm/sun4c.c: __init sun4c_paging_init()
> > arch/sparc64/mm/init.c: __init paging_init()
> > mm/page_alloc.c: __init free_area_init_nodes()
> > mm/page_alloc.c: __init free_area_init()
> > and
> > mm/memory_hotplug.c: hotadd_new_pgdat()
> > 
> > hotadd_new_pgdat can not be an __init function, but:
> > 
> > It is compiled for MEMORY_HOTPLUG configurations only
> > MEMORY_HOTPLUG depends on SPARSEMEM || X86_64_ACPI_NUMA
> > X86_64_ACPI_NUMA depends on X86_64
> > ARCH_FLATMEM_ENABLE depends on X86_32
> > ARCH_DISCONTIGMEM_ENABLE depends on X86_32
> > So X86_64_ACPI_NUMA implies SPARSEMEM, right?
> > 
> > So we can mark the stack of functions __init for !SPARSEMEM,
> > but we must mark them __meminit for SPARSEMEM configurations.
> > This is ok, because then the calls to alloc_bootmem_node are
> > also avoided.
> > 
> > Compile-tested on:
> > silly minimal config
> > defconfig x86_32
> > defconfig x86_64
> > defconfig x86_64 -HIBERNATION +MEMORY_HOTPLUG
> > 
> > Comments?
> > 
> > Signed-off-by: Alexander van Heukelum <heukelum@fastmail.fm>
> > 
> > 
> > diff --git a/mm/internal.h b/mm/internal.h
> > index 953f941..5b46b32 100644
> > --- a/mm/internal.h
> > +++ b/mm/internal.h
> > @@ -47,4 +47,17 @@ static inline unsigned long page_order(struct page *page)
> >  	VM_BUG_ON(!PageBuddy(page));
> >  	return page_private(page);
> >  }
> > +
> > +/*
> > + * FLATMEM and DISCONTIGMEM configurations use alloc_bootmem_node,
> > + * so all functions starting at paging_init should be marked __init
> > + * in those cases. SPARSEMEM, however, allows for memory hotplug,
> > + * and alloc_bootmem_node is not used.
> > + */
> > +#ifdef CONFIG_SPARSEMEM
> > +#define __paginginit __meminit
> > +#else
> > +#define __paginginit __init
> > +#endif
> > +
> >  #endif
> > diff --git a/mm/page_alloc.c b/mm/page_alloc.c
> > index b2838c2..859be40 100644
> > --- a/mm/page_alloc.c
> > +++ b/mm/page_alloc.c
> > @@ -3321,7 +3321,7 @@ static inline int pageblock_default_order(unsigned int order)
> >   *   - mark all memory queues empty
> >   *   - clear the memory bitmaps
> >   */
> > -static void __meminit free_area_init_core(struct pglist_data *pgdat,
> > +static void __paginginit free_area_init_core(struct pglist_data *pgdat,
> >  		unsigned long *zones_size, unsigned long *zholes_size)
> >  {
> >  	enum zone_type j;
> > @@ -3445,7 +3445,7 @@ static void __init_refok alloc_node_mem_map(struct pglist_data *pgdat)
> >  #endif /* CONFIG_FLAT_NODE_MEM_MAP */
> >  }
> >  
> > -void __meminit free_area_init_node(int nid, struct pglist_data *pgdat,
> > +void __paginginit free_area_init_node(int nid, struct pglist_data *pgdat,
> >  		unsigned long *zones_size, unsigned long node_start_pfn,
> >  		unsigned long *zholes_size)
> >  {
> > --
> > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> > the body of a message to majordomo@vger.kernel.org
> > More majordomo info at  http://vger.kernel.org/majordomo-info.html
> > Please read the FAQ at  http://www.tux.org/lkml/
> --
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at  http://www.tux.org/lkml/
> 

Gr{oetje,eeting}s,

						Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
							    -- Linus Torvalds

Lump xxxinit together with init if possible (was Re: Solve section mismatch for free_area_init_core.)

[Alexander van Heukelum]

On Tue, Feb 19, 2008 at 09:30:42AM +0100, Geert Uytterhoeven wrote:
> On Mon, 18 Feb 2008, Sam Ravnborg wrote:
> > I have (triggered by Geert) spend some time reviewing this patch
> > and I see no better way to fix it.
> > 
> > So it gets my:
> > 
> > Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
> 
> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>

Thanks!

I more than less expected people to scream "ugly, ugly!". Maybe you
could consider the following patch, instead?

In non-HOTPLUG configurations, devinit and init sections in vmlinux
are lumped together during the final link. There is no good reason
to warn about section mismatches between them in this case, because
all code is discarded at the same time. This patch moves the lumping-
together to the compile stage, which makes the unnecessary warnings
go away. Same for MEMORY_HOTPLUG/meminit and HOTPLUG_CPU/cpuinit.

On the condition that someone with knowledge in this area confirms
that this approach is right and not for some reason undesirable:

Signed-off-by: Alexander van Heukelum <heukelum@fastmail.fm>

 include/asm-generic/vmlinux.lds.h |   98 ++++++++----------------------------
 include/linux/init.h              |   27 ++++++++++
 2 files changed, 49 insertions(+), 76 deletions(-)

diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h
index f054778..742152b 100644
--- a/include/asm-generic/vmlinux.lds.h
+++ b/include/asm-generic/vmlinux.lds.h
@@ -9,46 +9,17 @@
 /* Align . to a 8 byte boundary equals to maximum function alignment. */
 #define ALIGN_FUNCTION()  . = ALIGN(8)
 
-/* The actual configuration determine if the init/exit sections
- * are handled as text/data or they can be discarded (which
- * often happens at runtime)
- */
-#ifdef CONFIG_HOTPLUG
-#define DEV_KEEP(sec)    *(.dev##sec)
-#define DEV_DISCARD(sec)
-#else
-#define DEV_KEEP(sec)
-#define DEV_DISCARD(sec) *(.dev##sec)
-#endif
-
-#ifdef CONFIG_HOTPLUG_CPU
-#define CPU_KEEP(sec)    *(.cpu##sec)
-#define CPU_DISCARD(sec)
-#else
-#define CPU_KEEP(sec)
-#define CPU_DISCARD(sec) *(.cpu##sec)
-#endif
-
-#if defined(CONFIG_MEMORY_HOTPLUG)
-#define MEM_KEEP(sec)    *(.mem##sec)
-#define MEM_DISCARD(sec)
-#else
-#define MEM_KEEP(sec)
-#define MEM_DISCARD(sec) *(.mem##sec)
-#endif
-
-
 /* .data section */
 #define DATA_DATA							\
 	*(.data)							\
 	*(.data.init.refok)						\
 	*(.ref.data)							\
-	DEV_KEEP(init.data)						\
-	DEV_KEEP(exit.data)						\
-	CPU_KEEP(init.data)						\
-	CPU_KEEP(exit.data)						\
-	MEM_KEEP(init.data)						\
-	MEM_KEEP(exit.data)						\
+	*(.devinit.data)						\
+	*(.devexit.data)						\
+	*(.cpuinit.data)						\
+	*(.cpuexit.data)						\
+	*(.meminit.data)						\
+	*(.memexit.data)						\
 	. = ALIGN(8);							\
 	VMLINUX_SYMBOL(__start___markers) = .;				\
 	*(__markers)							\
@@ -171,12 +142,12 @@
 	/* __*init sections */						\
 	__init_rodata : AT(ADDR(__init_rodata) - LOAD_OFFSET) {		\
 		*(.ref.rodata)						\
-		DEV_KEEP(init.rodata)					\
-		DEV_KEEP(exit.rodata)					\
-		CPU_KEEP(init.rodata)					\
-		CPU_KEEP(exit.rodata)					\
-		MEM_KEEP(init.rodata)					\
-		MEM_KEEP(exit.rodata)					\
+		*(.devinit.rodata)					\
+		*(.devexit.rodata)					\
+		*(.cpuinit.rodata)					\
+		*(.cpuexit.rodata)					\
+		*(.meminit.rodata)					\
+		*(.memexit.rodata)					\
 	}								\
 									\
 	/* Built-in module parameters. */				\
@@ -208,12 +179,12 @@
 		*(.ref.text)						\
 		*(.text.init.refok)					\
 		*(.exit.text.refok)					\
-	DEV_KEEP(init.text)						\
-	DEV_KEEP(exit.text)						\
-	CPU_KEEP(init.text)						\
-	CPU_KEEP(exit.text)						\
-	MEM_KEEP(init.text)						\
-	MEM_KEEP(exit.text)
+	*(.devinit.text)						\
+	*(.devexit.text)						\
+	*(.cpuinit.text)						\
+	*(.cpuexit.text)						\
+	*(.meminit.text)						\
+	*(.memexit.text)
 
 
 /* sched.text is aling to function alignment to secure we have same
@@ -242,35 +213,10 @@
 #define HEAD_TEXT  *(.head.text)
 
 /* init and exit section handling */
-#define INIT_DATA							\
-	*(.init.data)							\
-	DEV_DISCARD(init.data)						\
-	DEV_DISCARD(init.rodata)					\
-	CPU_DISCARD(init.data)						\
-	CPU_DISCARD(init.rodata)					\
-	MEM_DISCARD(init.data)						\
-	MEM_DISCARD(init.rodata)
-
-#define INIT_TEXT							\
-	*(.init.text)							\
-	DEV_DISCARD(init.text)						\
-	CPU_DISCARD(init.text)						\
-	MEM_DISCARD(init.text)
-
-#define EXIT_DATA							\
-	*(.exit.data)							\
-	DEV_DISCARD(exit.data)						\
-	DEV_DISCARD(exit.rodata)					\
-	CPU_DISCARD(exit.data)						\
-	CPU_DISCARD(exit.rodata)					\
-	MEM_DISCARD(exit.data)						\
-	MEM_DISCARD(exit.rodata)
-
-#define EXIT_TEXT							\
-	*(.exit.text)							\
-	DEV_DISCARD(exit.text)						\
-	CPU_DISCARD(exit.text)						\
-	MEM_DISCARD(exit.text)
+#define INIT_DATA	*(.init.data)
+#define INIT_TEXT	*(.init.text)
+#define EXIT_DATA	*(.exit.data)
+#define EXIT_TEXT	*(.exit.text)
 
 		/* DWARF debug sections.
 		Symbols in the DWARF debugging sections are relative to
diff --git a/include/linux/init.h b/include/linux/init.h
index fb58c04..8461f8f 100644
--- a/include/linux/init.h
+++ b/include/linux/init.h
@@ -83,28 +83,55 @@
 #define __exit          __section(.exit.text) __exitused __cold
 
 /* Used for HOTPLUG */
+#if defined(MODULE) || defined(CONFIG_HOTPLUG)
 #define __devinit        __section(.devinit.text) __cold
 #define __devinitdata    __section(.devinit.data)
 #define __devinitconst   __section(.devinit.rodata)
 #define __devexit        __section(.devexit.text) __exitused __cold
 #define __devexitdata    __section(.devexit.data)
 #define __devexitconst   __section(.devexit.rodata)
+#else
+#define __devinit        __section(.init.text) __cold
+#define __devinitdata    __section(.init.data)
+#define __devinitconst   __section(.init.rodata)
+#define __devexit        __section(.exit.text) __exitused __cold
+#define __devexitdata    __section(.exit.data)
+#define __devexitconst   __section(.exit.rodata)
+#endif
 
 /* Used for HOTPLUG_CPU */
+#if defined(MODULE) || defined(CONFIG_HOTPLUG_CPU)
 #define __cpuinit        __section(.cpuinit.text) __cold
 #define __cpuinitdata    __section(.cpuinit.data)
 #define __cpuinitconst   __section(.cpuinit.rodata)
 #define __cpuexit        __section(.cpuexit.text) __exitused __cold
 #define __cpuexitdata    __section(.cpuexit.data)
 #define __cpuexitconst   __section(.cpuexit.rodata)
+#else
+#define __cpuinit        __section(.init.text) __cold
+#define __cpuinitdata    __section(.init.data)
+#define __cpuinitconst   __section(.init.rodata)
+#define __cpuexit        __section(.exit.text) __exitused __cold
+#define __cpuexitdata    __section(.exit.data)
+#define __cpuexitconst   __section(.exit.rodata)
+#endif
 
 /* Used for MEMORY_HOTPLUG */
+#if defined(MODULE) || defined(CONFIG_MEMORY_HOTPLUG)
 #define __meminit        __section(.meminit.text) __cold
 #define __meminitdata    __section(.meminit.data)
 #define __meminitconst   __section(.meminit.rodata)
 #define __memexit        __section(.memexit.text) __exitused __cold
 #define __memexitdata    __section(.memexit.data)
 #define __memexitconst   __section(.memexit.rodata)
+#else
+#define __meminit        __section(.init.text) __cold
+#define __meminitdata    __section(.init.data)
+#define __meminitconst   __section(.init.rodata)
+#define __memexit        __section(.exit.text) __exitused __cold
+#define __memexitdata    __section(.exit.data)
+#define __memexitconst   __section(.exit.rodata)
+#endif
 
 /* For assembly routines */
 #define __HEAD		.section	".head.text","ax"

Re: Lump xxxinit together with init if possible (was Re: Solve section mismatch for free_area_init_core.)

[Sam Ravnborg]

Hi Alexander.
> I more than less expected people to scream "ugly, ugly!".

That was my first thought and the reason why it stayed in my inbox
for so long.
But I could not find a better way to do it. We could do it in
different ways but not better.

> Maybe you could consider the following patch, instead?
> In non-HOTPLUG configurations, devinit and init sections in vmlinux
> are lumped together during the final link. There is no good reason
> to warn about section mismatches between them in this case, because
> all code is discarded at the same time. This patch moves the lumping-
> together to the compile stage, which makes the unnecessary warnings
> go away. Same for MEMORY_HOTPLUG/meminit and HOTPLUG_CPU/cpuinit.

>From the commit where the seperate section were introduced:

    Introducing separate sections for __dev* (HOTPLUG),
    __cpu* (HOTPLUG_CPU) and __mem* (MEMORY_HOTPLUG)
    allows us to do a much more reliable Section mismatch
    check in modpost. We are no longer dependent on the actual
    configuration of for example HOTPLUG.

I think that explains it.

	Sam

Re: Lump xxxinit together with init if possible (was Re: Solve section mismatch for free_area_init_core.)

[Alexander van Heukelum]

On Sat, 23 Feb 2008 18:53:06 +0100, "Sam Ravnborg" <sam@ravnborg.org>
said:
> Hi Alexander.
> > I more than less expected people to scream "ugly, ugly!".
> 
> That was my first thought and the reason why it stayed in my inbox
> for so long.
> But I could not find a better way to do it. We could do it in
> different ways but not better.
> 
> > Maybe you could consider the following patch, instead?
> > In non-HOTPLUG configurations, devinit and init sections in vmlinux
> > are lumped together during the final link. There is no good reason
> > to warn about section mismatches between them in this case, because
> > all code is discarded at the same time. This patch moves the lumping-
> > together to the compile stage, which makes the unnecessary warnings
> > go away. Same for MEMORY_HOTPLUG/meminit and HOTPLUG_CPU/cpuinit.
> 
> From the commit where the seperate section were introduced:
> 
>     Introducing separate sections for __dev* (HOTPLUG),
>     __cpu* (HOTPLUG_CPU) and __mem* (MEMORY_HOTPLUG)
>     allows us to do a much more reliable Section mismatch
>     check in modpost. We are no longer dependent on the actual
>     configuration of for example HOTPLUG.
> 
> I think that explains it.

I should have looked at that commit first. Indeed, it does explain
why it is better to keep the sections separate. Thanks.
-- 
  Alexander van Heukelum
  heukelum@fastmail.fm

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