Re: [PATCH] atomic: cleanup asm-generic atomic*.h inclusion

From: Arun Sharma
Date: Fri Jun 17 2011 - 13:49:19 EST


On 6/17/11 10:28 AM, Mike Frysinger wrote:
On Fri, Jun 17, 2011 at 13:11, Arun Sharma wrote:
On 6/16/11 11:36 PM, Mike Frysinger wrote:
i'm not sure this doesnt break things. what tree exactly should i
apply this patch to to verify things ?

I tested 3.0-rc2 + patch 1 + patch 2 + this patch.

not sure what those patches are, so i picked at random:
Subject: [PATCH 2/3] atomic: move atomic_add_unless to generic code
Date: Tue, 7 Jun 2011 17:07:18 -0700
Message-Id:<1307491639-9864-2-git-send-email-asharma@xxxxxx>

Subject: [PATCH 1/3] atomic: use<linux/atomic.h>
Date: Mon, 6 Jun 2011 10:27:29 -0700
Message-Id:<1307381251-15729-1-git-send-email-asharma@xxxxxx>

Yes - these are the right patches.


but even after just these two, things fail because
include/asm-generic/atomic.h provides atomic_add_unless() already.
i'm guessing your patch 2/3 should have fixed that somehow since it
adds the func to linux/atomic.h.

Thanks for catching this. I missed it because I tested only on i386 and x86_64. Looks like only 4 archs are affected:

$ grep -r asm-generic.atomic.h *
blackfin/include/asm/atomic.h:# include <asm-generic/atomic.h>
microblaze/include/asm/atomic.h:#include <asm-generic/atomic.h>
mn10300/include/asm/atomic.h:#include <asm-generic/atomic.h>
score/include/asm/atomic.h:#include <asm-generic/atomic.h>

I believe the correct fix is:

--- a/include/asm-generic/atomic.h
+++ b/include/asm-generic/atomic.h
@@ -129,17 +129,6 @@ static inline void atomic_dec(atomic_t *v)

#define cmpxchg64_local(ptr, o, n) __cmpxchg64_local_generic((ptr), (o), (n))

-static inline int atomic_add_unless(atomic_t *v, int a, int u)
-{
- int c, old;
- c = atomic_read(v);
- while (c != u && (old = atomic_cmpxchg(v, c, c + a)) != c)
- c = old;
- return c != u;
-}
-
-#define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0)
-
static inline void atomic_clear_mask(unsigned long mask, unsigned long *addr)
{
unsigned long flags;

Could you help test this? I'll resend the patch series once I get confirmation.

-Arun
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