+ rcu-fix-sparse-shadowed-variable-warning.patch added to -mm tree

+ rcu-fix-sparse-shadowed-variable-warning.patch added to -mm tree

[akpm]

The patch titled
     rcu: fix sparse shadowed variable warning
has been added to the -mm tree.  Its filename is
     rcu-fix-sparse-shadowed-variable-warning.patch

Before you just go and hit "reply", please:
   a) Consider who else should be cc'ed
   b) Prefer to cc a suitable mailing list as well
   c) Ideally: find the original patch on the mailing list and do a
      reply-to-all to that, adding suitable additional cc's

*** Remember to use Documentation/SubmitChecklist when testing your code ***

See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this

The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/

------------------------------------------------------
Subject: rcu: fix sparse shadowed variable warning
From: Harvey Harrison <harvey.harrison@gmail.com>

kernel/rcuclassic.c:564:18: warning: symbol 'flags' shadows an earlier one
kernel/rcuclassic.c:527:16: originally declared here

Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 kernel/rcuclassic.c |    6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff -puN kernel/rcuclassic.c~rcu-fix-sparse-shadowed-variable-warning kernel/rcuclassic.c
--- a/kernel/rcuclassic.c~rcu-fix-sparse-shadowed-variable-warning
+++ a/kernel/rcuclassic.c
@@ -561,15 +561,15 @@ static void __rcu_process_callbacks(stru
 		local_irq_restore(flags);
 
 		if (rcu_batch_after(rdp->batch, rcp->pending)) {
-			unsigned long flags;
+			unsigned long flags2;
 
 			/* and start it/schedule start if it's a new batch */
-			spin_lock_irqsave(&rcp->lock, flags);
+			spin_lock_irqsave(&rcp->lock, flags2);
 			if (rcu_batch_after(rdp->batch, rcp->pending)) {
 				rcp->pending = rdp->batch;
 				rcu_start_batch(rcp);
 			}
-			spin_unlock_irqrestore(&rcp->lock, flags);
+			spin_unlock_irqrestore(&rcp->lock, flags2);
 		}
 	}
 
_

Patches currently in -mm which might be from harvey.harrison@gmail.com are

linux-next.patch
acpi-toshiba_acpic-fix-sparse-signedness-mismatch-warnings.patch
x86-fix-shadowed-variable-warning.patch
cifs-remove-global_extern-macro.patch
v4l-drx397xdc-sparse-annotations.patch
v4l-mt9m111c-make-function-static.patch
input-ads7846c-sparse-lock-annotation.patch
misdn-endian-annotations-for-struct-zt.patch
misdn-annotate-iomem-pointer-and-add-statics.patch
drivers-net-replace-__function__-with-__func__.patch
rcu-spinlocks-take-an-unsigned-long-flags.patch
rcu-fix-sparse-shadowed-variable-warning.patch
scsi-replace-__inline-with-inline.patch
scsi-aic79xx_core-fix-shadowed-variables-add-statics.patch
scsi-aic79xx-aic79xx_pcic-fix-shadowed-variables.patch
scsi-gdthc-use-unaligned-access-helpers.patch
scsi-use-the-common-hex_asc-array-rather-than-a-private-one.patch
mm-hugetlbc-make-functions-static-use-null-rather-than-0.patch
olpc-olpc_batteryc-sparse-endian-annotations.patch
include-replace-__function__-with-__func__.patch
misc-replace-__function__-with-__func__.patch
befs-annotate-fs32-on-tests-for-superblock-endianness.patch
byteorder-add-new-headers-for-make-headers-install.patch
pvrusb2-use-proper-byteorder-interface.patch

Re: + rcu-fix-sparse-shadowed-variable-warning.patch added to -mm tree

[Alexey Dobriyan]

> --- a/kernel/rcuclassic.c~rcu-fix-sparse-shadowed-variable-warning
> +++ a/kernel/rcuclassic.c
> @@ -561,15 +561,15 @@ static void __rcu_process_callbacks(stru
>  		local_irq_restore(flags);
>  
>  		if (rcu_batch_after(rdp->batch, rcp->pending)) {
> -			unsigned long flags;
> +			unsigned long flags2;
>  
>  			/* and start it/schedule start if it's a new batch */
> -			spin_lock_irqsave(&rcp->lock, flags);
> +			spin_lock_irqsave(&rcp->lock, flags2);
>  			if (rcu_batch_after(rdp->batch, rcp->pending)) {
>  				rcp->pending = rdp->batch;
>  				rcu_start_batch(rcp);
>  			}
> -			spin_unlock_irqrestore(&rcp->lock, flags);
> +			spin_unlock_irqrestore(&rcp->lock, flags2);
>  		}
>  	}

Bzzzrt... just remove second variable.

Re: + rcu-fix-sparse-shadowed-variable-warning.patch added to -mm tree

[Harvey Harrison]

On Thu, 2008-08-28 at 07:31 +0400, Alexey Dobriyan wrote:
> > --- a/kernel/rcuclassic.c~rcu-fix-sparse-shadowed-variable-warning
> > +++ a/kernel/rcuclassic.c
> > @@ -561,15 +561,15 @@ static void __rcu_process_callbacks(stru
> >  		local_irq_restore(flags);
> >  
> >  		if (rcu_batch_after(rdp->batch, rcp->pending)) {
> > -			unsigned long flags;
> > +			unsigned long flags2;
> >  
> >  			/* and start it/schedule start if it's a new batch */
> > -			spin_lock_irqsave(&rcp->lock, flags);
> > +			spin_lock_irqsave(&rcp->lock, flags2);
> >  			if (rcu_batch_after(rdp->batch, rcp->pending)) {
> >  				rcp->pending = rdp->batch;
> >  				rcu_start_batch(rcp);
> >  			}
> > -			spin_unlock_irqrestore(&rcp->lock, flags);
> > +			spin_unlock_irqrestore(&rcp->lock, flags2);
> >  		}
> >  	}
> 
> Bzzzrt... just remove second variable.
> 

>From my original e-mail:

It would be safe in this case to just remove the second declaration of flags
and reuse it as it is outside the local_irq_save/restore pair.  I did it
this
way in case there are future changes that might mix up the use of flags.

Feel free to just remove the second flags declaration if you'd rather do
it
that way.

Cheers,

Harvey