2008-08-04 18:21:31

by Adrian Bunk

Subject: [2.6 patch] fix mm/mm_init.c compilation

This patch fixes the following compile error with gcc 3.2:

<-- snip -->

...
CC mm/mm_init.o
/home/bunk/linux/kernel-2.6/git/linux-2.6/mm/mm_init.c:77:1: directives may not be used inside a macro argument
/home/bunk/linux/kernel-2.6/git/linux-2.6/mm/mm_init.c:76:47: unterminated argument list invoking macro "mminit_dprintk"
/home/bunk/linux/kernel-2.6/git/linux-2.6/mm/mm_init.c: In function `mminit_verify_pageflags_layout':
/home/bunk/linux/kernel-2.6/git/linux-2.6/mm/mm_init.c:80: `mminit_dprintk' undeclared (first use in this function)
/home/bunk/linux/kernel-2.6/git/linux-2.6/mm/mm_init.c:80: (Each undeclared identifier is reported only once
/home/bunk/linux/kernel-2.6/git/linux-2.6/mm/mm_init.c:80: for each function it appears in.)
/home/bunk/linux/kernel-2.6/git/linux-2.6/mm/mm_init.c:80: syntax error before numeric constant
make[2]: *** [mm/mm_init.o] Error 1

<-- snip -->

Reported-by: Adrian Bunk <[email protected]>
Signed-off-by: Adrian Bunk <[email protected]>

---

mm/mm_init.c | 13 ++++++++-----
1 file changed, 8 insertions(+), 5 deletions(-)

--- a/mm/mm_init.c
+++ b/mm/mm_init.c
@@ -63,6 +63,13 @@ void __init mminit_verify_pageflags_layout(void)
{
int shift, width;
unsigned long or_mask, add_mask;
+ int sections_shift;
+
+#ifdef SECTIONS_SHIFT
+ sections_shift = SECTIONS_SHIFT;
+#else
+ sections_shift = 0;
+#endif

shift = 8 * sizeof(unsigned long);
width = shift - SECTIONS_WIDTH - NODES_WIDTH - ZONES_WIDTH;
@@ -74,11 +81,7 @@ void __init mminit_verify_pageflags_layout(void)
NR_PAGEFLAGS);
mminit_dprintk(MMINIT_TRACE, "pageflags_layout_shifts",
"Section %d Node %d Zone %d\n",
-#ifdef SECTIONS_SHIFT
- SECTIONS_SHIFT,
-#else
- 0,
-#endif
+ sections_shift,
NODES_SHIFT,
ZONES_SHIFT);
mminit_dprintk(MMINIT_TRACE, "pageflags_layout_offsets",

2008-08-04 21:06:44

by Andrew Morton

Subject: Re: [2.6 patch] fix mm/mm_init.c compilation

On Mon, 4 Aug 2008 21:19:15 +0300
Adrian Bunk <[email protected]> wrote:

> This patch fixes the following compile error with gcc 3.2:
>
> <-- snip -->
>
> ...
> CC mm/mm_init.o
> /home/bunk/linux/kernel-2.6/git/linux-2.6/mm/mm_init.c:77:1: directives may not be used inside a macro argument
> /home/bunk/linux/kernel-2.6/git/linux-2.6/mm/mm_init.c:76:47: unterminated argument list invoking macro "mminit_dprintk"
> /home/bunk/linux/kernel-2.6/git/linux-2.6/mm/mm_init.c: In function `mminit_verify_pageflags_layout':
> /home/bunk/linux/kernel-2.6/git/linux-2.6/mm/mm_init.c:80: `mminit_dprintk' undeclared (first use in this function)
> /home/bunk/linux/kernel-2.6/git/linux-2.6/mm/mm_init.c:80: (Each undeclared identifier is reported only once
> /home/bunk/linux/kernel-2.6/git/linux-2.6/mm/mm_init.c:80: for each function it appears in.)
> /home/bunk/linux/kernel-2.6/git/linux-2.6/mm/mm_init.c:80: syntax error before numeric constant
> make[2]: *** [mm/mm_init.o] Error 1
>
> <-- snip -->
>
>
> --- a/mm/mm_init.c
> +++ b/mm/mm_init.c
> @@ -63,6 +63,13 @@ void __init mminit_verify_pageflags_layout(void)
> {
> int shift, width;
> unsigned long or_mask, add_mask;
> + int sections_shift;
> +
> +#ifdef SECTIONS_SHIFT
> + sections_shift = SECTIONS_SHIFT;
> +#else
> + sections_shift = 0;
> +#endif
>
> shift = 8 * sizeof(unsigned long);
> width = shift - SECTIONS_WIDTH - NODES_WIDTH - ZONES_WIDTH;
> @@ -74,11 +81,7 @@ void __init mminit_verify_pageflags_layout(void)
> NR_PAGEFLAGS);
> mminit_dprintk(MMINIT_TRACE, "pageflags_layout_shifts",
> "Section %d Node %d Zone %d\n",
> -#ifdef SECTIONS_SHIFT
> - SECTIONS_SHIFT,
> -#else
> - 0,
> -#endif
> + sections_shift,
> NODES_SHIFT,
> ZONES_SHIFT);
> mminit_dprintk(MMINIT_TRACE, "pageflags_layout_offsets",

OK, ifdefs inside macro expansion aren't a great idea.

Mel, is there any erason why we shouldn't do it this way?

include/linux/mmzone.h | 3 ++-
mm/mm_init.c | 4 ----

2 files changed, 2 insertions(+), 5 deletions(-)

diff -puN include/linux/mmzone.h~a include/linux/mmzone.h
--- a/include/linux/mmzone.h~a
+++ a/include/linux/mmzone.h
@@ -831,7 +831,7 @@ static inline unsigned long early_pfn_to
#ifdef CONFIG_SPARSEMEM

/*
- * SECTION_SHIFT #bits space required to store a section #
+ * SECTIONS_SHIFT #bits space required to store a section #
*
* PA_SECTION_SHIFT physical address to/from section number
* PFN_SECTION_SHIFT pfn to/from section number
@@ -973,6 +973,7 @@ static inline int pfn_present(unsigned l
#define early_pfn_valid(pfn) pfn_valid(pfn)
void sparse_init(void);
#else
+#define SECTIONS_SHIFT 0
#define sparse_init() do {} while (0)
#define sparse_index_init(_sec, _nid) do {} while (0)
#endif /* CONFIG_SPARSEMEM */
diff -puN mm/mm_init.c~a mm/mm_init.c
--- a/mm/mm_init.c~a
+++ a/mm/mm_init.c
@@ -74,11 +74,7 @@ void __init mminit_verify_pageflags_layo
NR_PAGEFLAGS);
mminit_dprintk(MMINIT_TRACE, "pageflags_layout_shifts",
"Section %d Node %d Zone %d\n",
-#ifdef SECTIONS_SHIFT
SECTIONS_SHIFT,
-#else
- 0,
-#endif
NODES_SHIFT,
ZONES_SHIFT);
mminit_dprintk(MMINIT_TRACE, "pageflags_layout_offsets",
_

2008-08-05 07:51:57

by Mel Gorman

Subject: Re: [2.6 patch] fix mm/mm_init.c compilation

On (04/08/08 14:05), Andrew Morton didst pronounce:
> On Mon, 4 Aug 2008 21:19:15 +0300
> Adrian Bunk <[email protected]> wrote:
>
> > This patch fixes the following compile error with gcc 3.2:
> >
> > <-- snip -->
> >
> > ...
> > CC mm/mm_init.o
> > /home/bunk/linux/kernel-2.6/git/linux-2.6/mm/mm_init.c:77:1: directives may not be used inside a macro argument
> > /home/bunk/linux/kernel-2.6/git/linux-2.6/mm/mm_init.c:76:47: unterminated argument list invoking macro "mminit_dprintk"
> > /home/bunk/linux/kernel-2.6/git/linux-2.6/mm/mm_init.c: In function `mminit_verify_pageflags_layout':
> > /home/bunk/linux/kernel-2.6/git/linux-2.6/mm/mm_init.c:80: `mminit_dprintk' undeclared (first use in this function)
> > /home/bunk/linux/kernel-2.6/git/linux-2.6/mm/mm_init.c:80: (Each undeclared identifier is reported only once
> > /home/bunk/linux/kernel-2.6/git/linux-2.6/mm/mm_init.c:80: for each function it appears in.)
> > /home/bunk/linux/kernel-2.6/git/linux-2.6/mm/mm_init.c:80: syntax error before numeric constant
> > make[2]: *** [mm/mm_init.o] Error 1
> >
> > <-- snip -->
> >
> >
> > --- a/mm/mm_init.c
> > +++ b/mm/mm_init.c
> > @@ -63,6 +63,13 @@ void __init mminit_verify_pageflags_layout(void)
> > {
> > int shift, width;
> > unsigned long or_mask, add_mask;
> > + int sections_shift;
> > +
> > +#ifdef SECTIONS_SHIFT
> > + sections_shift = SECTIONS_SHIFT;
> > +#else
> > + sections_shift = 0;
> > +#endif
> >
> > shift = 8 * sizeof(unsigned long);
> > width = shift - SECTIONS_WIDTH - NODES_WIDTH - ZONES_WIDTH;
> > @@ -74,11 +81,7 @@ void __init mminit_verify_pageflags_layout(void)
> > NR_PAGEFLAGS);
> > mminit_dprintk(MMINIT_TRACE, "pageflags_layout_shifts",
> > "Section %d Node %d Zone %d\n",
> > -#ifdef SECTIONS_SHIFT
> > - SECTIONS_SHIFT,
> > -#else
> > - 0,
> > -#endif
> > + sections_shift,
> > NODES_SHIFT,
> > ZONES_SHIFT);
> > mminit_dprintk(MMINIT_TRACE, "pageflags_layout_offsets",
>
> OK, ifdefs inside macro expansion aren't a great idea.
>
> Mel, is there any erason why we shouldn't do it this way?
>

The only minor nit is SECTIONS_SHIFT is defined outside of SPARSEMEM even
though it has no meaning there. There is no problem with this as such but
someone being silly might use SECTIONS_SHIFT accidently. If this sort of
behaviour was considered a possibility, we could add something like this to
mm/mm_init.c instead?

#ifndef SECTIONS_SHIFT
#define SECTIONS_SHIFT 0
#endif /* SECTIONS_SHIFT */

> include/linux/mmzone.h | 3 ++-
> mm/mm_init.c | 4 ----
>
> 2 files changed, 2 insertions(+), 5 deletions(-)
>
> diff -puN include/linux/mmzone.h~a include/linux/mmzone.h
> --- a/include/linux/mmzone.h~a
> +++ a/include/linux/mmzone.h
> @@ -831,7 +831,7 @@ static inline unsigned long early_pfn_to
> #ifdef CONFIG_SPARSEMEM
>
> /*
> - * SECTION_SHIFT #bits space required to store a section #
> + * SECTIONS_SHIFT #bits space required to store a section #
> *
> * PA_SECTION_SHIFT physical address to/from section number
> * PFN_SECTION_SHIFT pfn to/from section number
> @@ -973,6 +973,7 @@ static inline int pfn_present(unsigned l
> #define early_pfn_valid(pfn) pfn_valid(pfn)
> void sparse_init(void);
> #else
> +#define SECTIONS_SHIFT 0
> #define sparse_init() do {} while (0)
> #define sparse_index_init(_sec, _nid) do {} while (0)
> #endif /* CONFIG_SPARSEMEM */
> diff -puN mm/mm_init.c~a mm/mm_init.c
> --- a/mm/mm_init.c~a
> +++ a/mm/mm_init.c
> @@ -74,11 +74,7 @@ void __init mminit_verify_pageflags_layo
> NR_PAGEFLAGS);
> mminit_dprintk(MMINIT_TRACE, "pageflags_layout_shifts",
> "Section %d Node %d Zone %d\n",
> -#ifdef SECTIONS_SHIFT
> SECTIONS_SHIFT,
> -#else
> - 0,
> -#endif
> NODES_SHIFT,
> ZONES_SHIFT);
> mminit_dprintk(MMINIT_TRACE, "pageflags_layout_offsets",
> _
>

--
Mel Gorman
Part-time Phd Student Linux Technology Center
University of Limerick IBM Dublin Software Lab

2008-08-05 09:12:18

by Andrew Morton

Subject: Re: [2.6 patch] fix mm/mm_init.c compilation

On Tue, 5 Aug 2008 08:51:23 +0100 Mel Gorman <[email protected]> wrote:

> > > --- a/mm/mm_init.c
> > > +++ b/mm/mm_init.c
> > > @@ -63,6 +63,13 @@ void __init mminit_verify_pageflags_layout(void)
> > > {
> > > int shift, width;
> > > unsigned long or_mask, add_mask;
> > > + int sections_shift;
> > > +
> > > +#ifdef SECTIONS_SHIFT
> > > + sections_shift = SECTIONS_SHIFT;
> > > +#else
> > > + sections_shift = 0;
> > > +#endif
> > >
> > > shift = 8 * sizeof(unsigned long);
> > > width = shift - SECTIONS_WIDTH - NODES_WIDTH - ZONES_WIDTH;
> > > @@ -74,11 +81,7 @@ void __init mminit_verify_pageflags_layout(void)
> > > NR_PAGEFLAGS);
> > > mminit_dprintk(MMINIT_TRACE, "pageflags_layout_shifts",
> > > "Section %d Node %d Zone %d\n",
> > > -#ifdef SECTIONS_SHIFT
> > > - SECTIONS_SHIFT,
> > > -#else
> > > - 0,
> > > -#endif
> > > + sections_shift,
> > > NODES_SHIFT,
> > > ZONES_SHIFT);
> > > mminit_dprintk(MMINIT_TRACE, "pageflags_layout_offsets",
> >
> > OK, ifdefs inside macro expansion aren't a great idea.
> >
> > Mel, is there any erason why we shouldn't do it this way?
> >
>
> The only minor nit is SECTIONS_SHIFT is defined outside of SPARSEMEM even
> though it has no meaning there. There is no problem with this as such but
> someone being silly might use SECTIONS_SHIFT accidently. If this sort of
> behaviour was considered a possibility, we could add something like this to
> mm/mm_init.c instead?

That sounds sane.

diff -puN mm/mm_init.c~mm_initc-avoid-ifdef-inside-macro-expansion mm/mm_init.c
--- a/mm/mm_init.c~mm_initc-avoid-ifdef-inside-macro-expansion
+++ a/mm/mm_init.c
@@ -14,6 +14,10 @@
#ifdef CONFIG_DEBUG_MEMORY_INIT
int __meminitdata mminit_loglevel;

+#ifndef SECTIONS_SHIFT
+#define SECTIONS_SHIFT 0
+#endif
+
/* The zonelists are simply reported, validation is manual. */
void mminit_verify_zonelist(void)
{
@@ -74,11 +78,7 @@ void __init mminit_verify_pageflags_layo
NR_PAGEFLAGS);
mminit_dprintk(MMINIT_TRACE, "pageflags_layout_shifts",
"Section %d Node %d Zone %d\n",
-#ifdef SECTIONS_SHIFT
SECTIONS_SHIFT,
-#else
- 0,
-#endif
NODES_SHIFT,
ZONES_SHIFT);
mminit_dprintk(MMINIT_TRACE, "pageflags_layout_offsets",
_