Date: Sun, 12 Sep 2004 23:48:39 +0400
From: Alex Zarochentsev <zam@namesys.com>
To: Paul Jackson <pj@sgi.com>
Cc: reiser@namesys.com, linux-kernel@vger.kernel.org, akpm@osdl.org
Subject: Re: 2.6.9-rc1-mm4 sparc reiser4 build broken - undefined atomic_sub_and_test
Message-ID: <20040912194839.GV6294@backtop.namesys.com>
References: <20040912031235.48c738ae.pj@sgi.com> <20040912163352.GA27411@backtop.namesys.com> <20040912114948.49095cd2.pj@sgi.com>
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On Sun, Sep 12, 2004 at 11:49:48AM -0700, Paul Jackson wrote:
> Alex writes:
> > please try this patch:
> > ...
> > +++ reiser4-linux-2.6/fs/reiser4/flush_queue.c
> > ...
> > +#include <asm/atomic.h>
> 
> This patch doesn't help.
> 
> Both with and without this patch, I observe the following:
> 
>  1) include/asm/atomic.h is listed in fs/reiser4/.flush_queue.o.cmd
>     (apparently it is included indirectly, even if not explicitly so)
>  2) The command:
> 	make fs/reiser4/flush_queue.o
>     produces the output:
> 	fs/reiser4/flush_queue.c: In function `end_io_handler':
> 	fs/reiser4/flush_queue.c:451: warning: implicit declaration of function `atomic_sub_and_test'
>  3) include/asm/atomic.h (which is include/asm-sparc/atomic.h via the asm symlink)
>     does _not_ mention atomic_sub_and_test
>  4) include/asm-sparc64/atomic.h _does_ mention atomic_sub_and_test (and build ok)
>  5) the final kernel link fails with:
> 	fs/built-in.o(.text+0x58618): In function `end_io_handler':
> 	: undefined reference to `atomic_sub_and_test'
> 	make[1]: *** [arch/sparc/boot/image] Error 1
> 
> I also saw an email from Bill Irwin go by, explaining that he did not
> choose to add atomic_sub_and_test to include/asm-sparc/atomic.h, which
> email is consistent with my observation that sparc atomic.h does not
> define atomic_sub_and_test.
> 
> It would seem that your asm-sparc/atomic.h is not the same as mine.
> 
> I believe that mine is the one in 2.6.9-rc1-mm4, which is the same as
> the latest one in Linus' bk tree, since its most recent change of:
> 
>   1.10 04/05/14 19:00:05 akpm@osdl.org[torvalds] +10 -0
>   Implement atomic_inc_and_test() on various architectures
> 
> and continuing through now.  This atomic.h is 4550 bytes long, with an
> md5sum of:
> 
> 	90eb38997e21e579fc1cd1617180d630  include/asm-sparc/atomic.h
> 
> And, to repeat myself, it has no mention of atomic_sub_and_test.

ah, that was atomic24_sub_and_test(), marked as
/* This is the old 24-bit implementation. ... */

I think adding the wrappers for atomic_sub_and_test() wouldn't be wrong:

===== include/asm-sparc/atomic.h 1.10 vs edited =====
--- 1.10/include/asm-sparc/atomic.h	Sat May 15 06:00:05 2004
+++ edited/include/asm-sparc/atomic.h	Sun Sep 12 23:37:05 2004
@@ -44,8 +44,9 @@
  * other cases.
  */
 #define atomic_inc_and_test(v) (atomic_inc_return(v) == 0)
-
 #define atomic_dec_and_test(v) (atomic_dec_return(v) == 0)
+#define atomic_add_and_test(i, v) (atomic_add_return(i, v) == 0)
+#define atomic_sub_and_test(i, v) (atomic_sub_return(i, v) == 0)
 
 /* This is the old 24-bit implementation.  It's still used internally
  * by some sparc-specific code, notably the semaphore implementation.
=============================

Interesting that asm-sparc64/atomic.h defines atomic_add/sub_and_test().

>                           I won't rest till it's the best ...
>                           Programmer, Linux Scalability
>                           Paul Jackson <pj@sgi.com> 1.650.933.1373

-- 
Alex.
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