All of lore.kernel.org
 help / color / mirror / Atom feed
* [RFC][PATCH v2] irq_work: Drop cmpxchg result
@ 2010-11-16 18:02 Sergio Aguirre
  2010-11-16 18:16 ` Eric Dumazet
                   ` (2 more replies)
  0 siblings, 3 replies; 5+ messages in thread
From: Sergio Aguirre @ 2010-11-16 18:02 UTC (permalink / raw)
  To: LKML
  Cc: Sergio Aguirre, Huang Ying, Martin Schwidefsky, Ingo Molnar,
	Kyle McMartin, Peter Zijlstra

This solves this compilation warning:

kernel/irq_work.c: In function 'irq_work_run':
kernel/irq_work.c:148: warning: value computed is not used

Signed-off-by: Sergio Aguirre <saaguirre@ti.com>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
---

Changelog:
v2 - Keep ignoring the cmpxchg return value, as pointed
     out by Peter Zijlstra, and update patch subject/description

v1 - Initial version
     (found here: https://patchwork.kernel.org/patch/328662/)

 kernel/irq_work.c |    4 +++-
 1 files changed, 3 insertions(+), 1 deletions(-)

diff --git a/kernel/irq_work.c b/kernel/irq_work.c
index f16763f..90f8819 100644
--- a/kernel/irq_work.c
+++ b/kernel/irq_work.c
@@ -145,7 +145,9 @@ void irq_work_run(void)
 		 * Clear the BUSY bit and return to the free state if
 		 * no-one else claimed it meanwhile.
 		 */
-		cmpxchg(&entry->next, next_flags(NULL, IRQ_WORK_BUSY), NULL);
+		(void)cmpxchg(&entry->next,
+			      next_flags(NULL, IRQ_WORK_BUSY),
+			      NULL);
 	}
 }
 EXPORT_SYMBOL_GPL(irq_work_run);
-- 
1.7.0.4


^ permalink raw reply related	[flat|nested] 5+ messages in thread

* Re: [RFC][PATCH v2] irq_work: Drop cmpxchg result
  2010-11-16 18:02 [RFC][PATCH v2] irq_work: Drop cmpxchg result Sergio Aguirre
@ 2010-11-16 18:16 ` Eric Dumazet
  2010-11-16 19:32   ` Aguirre, Sergio
  2010-11-16 18:26 ` Peter Zijlstra
  2010-11-18 14:09 ` [tip:perf/urgent] irq_work: Drop cmpxchg() result tip-bot for Sergio Aguirre
  2 siblings, 1 reply; 5+ messages in thread
From: Eric Dumazet @ 2010-11-16 18:16 UTC (permalink / raw)
  To: Sergio Aguirre
  Cc: LKML, Huang Ying, Martin Schwidefsky, Ingo Molnar, Kyle McMartin,
	Peter Zijlstra

Le mardi 16 novembre 2010 à 12:02 -0600, Sergio Aguirre a écrit :
> This solves this compilation warning:
> 
> kernel/irq_work.c: In function 'irq_work_run':
> kernel/irq_work.c:148: warning: value computed is not used

Just curious, what is your compiler version ?

Thanks



^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: [RFC][PATCH v2] irq_work: Drop cmpxchg result
  2010-11-16 18:02 [RFC][PATCH v2] irq_work: Drop cmpxchg result Sergio Aguirre
  2010-11-16 18:16 ` Eric Dumazet
@ 2010-11-16 18:26 ` Peter Zijlstra
  2010-11-18 14:09 ` [tip:perf/urgent] irq_work: Drop cmpxchg() result tip-bot for Sergio Aguirre
  2 siblings, 0 replies; 5+ messages in thread
From: Peter Zijlstra @ 2010-11-16 18:26 UTC (permalink / raw)
  To: Sergio Aguirre
  Cc: LKML, Huang Ying, Martin Schwidefsky, Ingo Molnar, Kyle McMartin

On Tue, 2010-11-16 at 12:02 -0600, Sergio Aguirre wrote:
> This solves this compilation warning:
> 
> kernel/irq_work.c: In function 'irq_work_run':
> kernel/irq_work.c:148: warning: value computed is not used
> 
Thanks!

^ permalink raw reply	[flat|nested] 5+ messages in thread

* RE: [RFC][PATCH v2] irq_work: Drop cmpxchg result
  2010-11-16 18:16 ` Eric Dumazet
@ 2010-11-16 19:32   ` Aguirre, Sergio
  0 siblings, 0 replies; 5+ messages in thread
From: Aguirre, Sergio @ 2010-11-16 19:32 UTC (permalink / raw)
  To: Eric Dumazet
  Cc: LKML, Huang Ying, Martin Schwidefsky, Ingo Molnar, Kyle McMartin,
	Peter Zijlstra



> -----Original Message-----
> From: Eric Dumazet [mailto:eric.dumazet@gmail.com]
> Sent: Tuesday, November 16, 2010 12:17 PM
> To: Aguirre, Sergio
> Cc: LKML; Huang Ying; Martin Schwidefsky; Ingo Molnar; Kyle McMartin;
> Peter Zijlstra
> Subject: Re: [RFC][PATCH v2] irq_work: Drop cmpxchg result
> 
> Le mardi 16 novembre 2010 à 12:02 -0600, Sergio Aguirre a écrit :
> > This solves this compilation warning:
> >
> > kernel/irq_work.c: In function 'irq_work_run':
> > kernel/irq_work.c:148: warning: value computed is not used
> 
> Just curious, what is your compiler version ?

I'm using a Code Sourcery ARM toolchain, and compiling for TI OMAP2+ chips (armv7-a)

# arm-none-linux-gnueabi-gcc --version
arm-none-linux-gnueabi-gcc (Sourcery G++ Lite 2010q1-202) 4.4.1
Copyright (C) 2009 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

Regards,
Sergio

> 
> Thanks
> 


^ permalink raw reply	[flat|nested] 5+ messages in thread

* [tip:perf/urgent] irq_work: Drop cmpxchg() result
  2010-11-16 18:02 [RFC][PATCH v2] irq_work: Drop cmpxchg result Sergio Aguirre
  2010-11-16 18:16 ` Eric Dumazet
  2010-11-16 18:26 ` Peter Zijlstra
@ 2010-11-18 14:09 ` tip-bot for Sergio Aguirre
  2 siblings, 0 replies; 5+ messages in thread
From: tip-bot for Sergio Aguirre @ 2010-11-18 14:09 UTC (permalink / raw)
  To: linux-tip-commits
  Cc: linux-kernel, hpa, mingo, a.p.zijlstra, schwidefsky, kyle,
	ying.huang, saaguirre, tglx, mingo

Commit-ID:  94e8ba728640dc01375a14e337f3b892bfacbeeb
Gitweb:     http://git.kernel.org/tip/94e8ba728640dc01375a14e337f3b892bfacbeeb
Author:     Sergio Aguirre <saaguirre@ti.com>
AuthorDate: Tue, 16 Nov 2010 12:02:47 -0600
Committer:  Ingo Molnar <mingo@elte.hu>
CommitDate: Thu, 18 Nov 2010 13:18:47 +0100

irq_work: Drop cmpxchg() result

The compiler warned us about:

 kernel/irq_work.c: In function 'irq_work_run':
 kernel/irq_work.c:148: warning: value computed is not used

Dropping the cmpxchg() result is indeed weird, but correct -
so annotate away the warning.

Signed-off-by: Sergio Aguirre <saaguirre@ti.com>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1289930567-17828-1-git-send-email-saaguirre@ti.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
 kernel/irq_work.c |    4 +++-
 1 files changed, 3 insertions(+), 1 deletions(-)

diff --git a/kernel/irq_work.c b/kernel/irq_work.c
index f16763f..90f8819 100644
--- a/kernel/irq_work.c
+++ b/kernel/irq_work.c
@@ -145,7 +145,9 @@ void irq_work_run(void)
 		 * Clear the BUSY bit and return to the free state if
 		 * no-one else claimed it meanwhile.
 		 */
-		cmpxchg(&entry->next, next_flags(NULL, IRQ_WORK_BUSY), NULL);
+		(void)cmpxchg(&entry->next,
+			      next_flags(NULL, IRQ_WORK_BUSY),
+			      NULL);
 	}
 }
 EXPORT_SYMBOL_GPL(irq_work_run);

^ permalink raw reply related	[flat|nested] 5+ messages in thread

end of thread, other threads:[~2010-11-18 14:10 UTC | newest]

Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2010-11-16 18:02 [RFC][PATCH v2] irq_work: Drop cmpxchg result Sergio Aguirre
2010-11-16 18:16 ` Eric Dumazet
2010-11-16 19:32   ` Aguirre, Sergio
2010-11-16 18:26 ` Peter Zijlstra
2010-11-18 14:09 ` [tip:perf/urgent] irq_work: Drop cmpxchg() result tip-bot for Sergio Aguirre

This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.