Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1228479 > unrolled thread

[PATCH 0/3] fix allmodconfig failure of avr32

Back to article view | Back to linux.kernel

Contents

  [PATCH 0/3] fix allmodconfig failure of avr32 Sudip Mukherjee <sudipm.mukherjee@gmail.com> - 2015-09-19 19:20 +0200
    [PATCH 3/3] page-flags: rectify forward declaration Sudip Mukherjee <sudipm.mukherjee@gmail.com> - 2015-09-19 19:20 +0200
      Re: [PATCH 3/3] page-flags: rectify forward declaration Andrew Morton <akpm@linux-foundation.org> - 2015-09-22 00:40 +0200
        Re: [PATCH 3/3] page-flags: rectify forward declaration Sudip Mukherjee <sudipm.mukherjee@gmail.com> - 2015-09-22 11:00 +0200

#1228479 — [PATCH 0/3] fix allmodconfig failure of avr32

Build of allmodconfig with avr32 used to fail with the errors:
error: implicit declaration of function 'pci_iomap'
error: implicit declaration of function 'pci_iounmap'
and
"at91_pmc_base" [drivers/usb/gadget/udc/atmel_usba_udc.ko] undefined!

First two patches fixes these two problems. Third patch is related to a
build warning:
warning: 'compound_head' declared inline after being called.
warning: previous declaration of 'compound_head' was here.

regards
sudip

Sudip Mukherjee (3):
  avr32: fix build failure
  usb: gadget: at91_udc: mention proper dependency
  page-flags: rectify forward declaration

 arch/avr32/include/asm/io.h    | 13 +++++++++++++
 drivers/usb/gadget/udc/Kconfig |  2 +-
 include/linux/page-flags.h     |  2 +-
 3 files changed, 15 insertions(+), 2 deletions(-)

-- 
1.9.1

--
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/

[toc] | [next] | [standalone]

#1228481 — [PATCH 3/3] page-flags: rectify forward declaration

compound_head is defined as inline in page-flags.h but in the forward
declaration of compound_head in the same file missed "inline". As a result
we got plenty of build warnings while building for some architecture
like avr32. The warning showed as:
warning: 'compound_head' declared inline after being called.
warning: previous declaration of 'compound_head' was here

Signed-off-by: Sudip Mukherjee <sudip@vectorindia.org>
---

tested build with avr32 and also with x86_64 allmodconfig to verify that
nothing breaks due to this change.

 include/linux/page-flags.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h
index ab1a0e9..2a2391c 100644
--- a/include/linux/page-flags.h
+++ b/include/linux/page-flags.h
@@ -227,7 +227,7 @@ static inline int __TestClearPage##uname(struct page *page) { return 0; }
 struct page;
 static inline int PageCompound(struct page *page);
 static inline int PageTail(struct page *page);
-static struct page *compound_head(struct page *page);
+static inline struct page *compound_head(struct page *page);
 
 __PAGEFLAG(Locked, locked, PF_NO_TAIL)
 PAGEFLAG(Error, error, PF_NO_COMPOUND) TESTCLEARFLAG(Error, error, PF_NO_COMPOUND)
-- 
1.9.1

--
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/

[toc] | [prev] | [next] | [standalone]

#1229798 — Re: [PATCH 3/3] page-flags: rectify forward declaration

On Sat, 19 Sep 2015 22:42:59 +0530 Sudip Mukherjee <sudipm.mukherjee@gmail.com> wrote:

> compound_head is defined as inline in page-flags.h but in the forward
> declaration of compound_head in the same file missed "inline". As a result
> we got plenty of build warnings while building for some architecture
> like avr32. The warning showed as:
> warning: 'compound_head' declared inline after being called.
> warning: previous declaration of 'compound_head' was here
> 
> ...
>
> --- a/include/linux/page-flags.h
> +++ b/include/linux/page-flags.h
> @@ -227,7 +227,7 @@ static inline int __TestClearPage##uname(struct page *page) { return 0; }
>  struct page;
>  static inline int PageCompound(struct page *page);
>  static inline int PageTail(struct page *page);
> -static struct page *compound_head(struct page *page);
> +static inline struct page *compound_head(struct page *page);
>  
>  __PAGEFLAG(Locked, locked, PF_NO_TAIL)
>  PAGEFLAG(Error, error, PF_NO_COMPOUND) TESTCLEARFLAG(Error, error, PF_NO_COMPOUND)

Yes, that's an error, in -mm due to Kirill's page-flags patches.


The code is effectively doing

static inline XXX foo(...);

static inline YYY bar(...)
{
	foo(...);
}

inline XXX foo(...)
{
	...
}

ie: asking gcc to inline a forward-defined function.  That does work,
but it's unusual and unexpected, and it's a bit unwise to expect the
compiler to do unusual and more difficult things.

Is it fixable?  Can we use the traditional define-before-using structure?

Also, I'm finding that the patch series introduces a pretty large
bisection hole:

include/linux/page-flags.h: In function 'PageYoung':
include/linux/page-flags.h:327: error: implicit declaration of function 'PF_ANY'
include/linux/page-flags.h:327: error: invalid type argument of '->' (have 'int')
include/linux/page-flags.h:327: error: invalid type argument of '->' (have 'int')

which later gets fixed up by
page-flags-rectify-forward-declaration.patch.

Maybe it's time to do a wholesale refactoring of the patchset?
--
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/

[toc] | [prev] | [next] | [standalone]

#1229988 — Re: [PATCH 3/3] page-flags: rectify forward declaration

On Mon, Sep 21, 2015 at 03:35:09PM -0700, Andrew Morton wrote:
> On Sat, 19 Sep 2015 22:42:59 +0530 Sudip Mukherjee <sudipm.mukherjee@gmail.com> wrote:
> 
<snip>
> 
> Is it fixable?  Can we use the traditional define-before-using structure?
How about this:

diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h
index ab1a0e9..d7a1055 100644
--- a/include/linux/page-flags.h
+++ b/include/linux/page-flags.h
@@ -133,6 +133,19 @@ enum pageflags {
 
 #ifndef __GENERATING_BOUNDS_H
 
+/* Forward declarations */
+struct page;
+static inline int PageCompound(struct page *page);
+static inline int PageTail(struct page *page);
+static inline struct page *compound_head(struct page *page)
+{
+	unsigned long head = READ_ONCE(page->compound_head);
+
+	if (unlikely(head & 1))
+		return (struct page *) (head - 1);
+	return page;
+}
+
 /* Page flags policies wrt compound pages */
 #define PF_ANY(page, enforce)	page
 #define PF_HEAD(page, enforce)	compound_head(page)
@@ -223,12 +236,6 @@ static inline int __TestClearPage##uname(struct page *page) { return 0; }
 #define TESTSCFLAG_FALSE(uname)						\
 	TESTSETFLAG_FALSE(uname) TESTCLEARFLAG_FALSE(uname)
 
-/* Forward declarations */
-struct page;
-static inline int PageCompound(struct page *page);
-static inline int PageTail(struct page *page);
-static struct page *compound_head(struct page *page);
-
 __PAGEFLAG(Locked, locked, PF_NO_TAIL)
 PAGEFLAG(Error, error, PF_NO_COMPOUND) TESTCLEARFLAG(Error, error, PF_NO_COMPOUND)
 PAGEFLAG(Referenced, referenced, PF_HEAD)
@@ -450,15 +457,6 @@ static inline void clear_compound_head(struct page *page)
 	WRITE_ONCE(page->compound_head, 0);
 }
 
-static inline struct page *compound_head(struct page *page)
-{
-	unsigned long head = READ_ONCE(page->compound_head);
-
-	if (unlikely(head & 1))
-		return (struct page *) (head - 1);
-	return page;
-}
-
 static inline int PageCompound(struct page *page)
 {
 	return PageHead(page) || PageTail(page);


---
It builds properly. Tested with allmodconfig of x86_64 and avr32.

> 
> Also, I'm finding that the patch series introduces a pretty large
> bisection hole:
> 
> include/linux/page-flags.h: In function 'PageYoung':
> include/linux/page-flags.h:327: error: implicit declaration of function 'PF_ANY'
> include/linux/page-flags.h:327: error: invalid type argument of '->' (have 'int')
> include/linux/page-flags.h:327: error: invalid type argument of '->' (have 'int')
> 
> which later gets fixed up by
> page-flags-rectify-forward-declaration.patch.
How to test this? Should I apply them on top of v4.2 and bisect? And I
don't see any relation between the first two patches and this patch of
the series, then how does it fail in bisect? Am I missing something?
Confused.. :(
> 
> Maybe it's time to do a wholesale refactoring of the patchset?
If this patch is the first in the series will that help?
And besides I got the auto mail from you that the patch is applied.
Now totally confused.. :(

regards
sudip
--
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/

[toc] | [prev] | [standalone]

Back to top | Article view | linux.kernel

csiph-web