From: Dave Chinner <david@fromorbit.com>
To: Joe Perches <joe@perches.com>
Cc: peterz@infradead.org, Pranith Kumar <pranith@gatech.edu>,
linux-kernel@vger.kernel.org, xfs@oss.sgi.com, mingo@redhat.com,
davidlohr@hp.com, Pranith Kumar <bobby.prani@gmail.com>,
tim.c.chen@linux.intel.com
Subject: Re: [RFC PATCH 1/1] cleanup: use bool as return type for rwsem_is_locked
Date: Sun, 8 Jun 2014 09:44:11 +1000 [thread overview]
Message-ID: <20140607234411.GA9508@dastard> (raw)
In-Reply-To: <1402108770.25112.5.camel@joe-AO725>
On Fri, Jun 06, 2014 at 07:39:30PM -0700, Joe Perches wrote:
> On Fri, 2014-06-06 at 21:41 -0400, Pranith Kumar wrote:
> > On 06/06/2014 08:59 PM, Pranith Kumar wrote:
> > > On 06/06/2014 08:18 PM, Dave Chinner wrote:
> > >> If you are going to change the return type to bool, then you should
> > >> also remove the manual "!!" conversions to a boolean return and let
> > >> the compiler do it in the most optimal way.
> > > Agreed, please find patch below:
> > Simplify the "!!" condition. This is much simpler. :)
> []
> > diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c
>
> > @@ -285,25 +285,25 @@ xfs_ilock_demote(
> > }
> >
> > #if defined(DEBUG) || defined(XFS_WARN)
> > -int
> > +bool
> > xfs_isilocked(
> > xfs_inode_t *ip,
> > uint lock_flags)
> > {
> > if (lock_flags & (XFS_ILOCK_EXCL|XFS_ILOCK_SHARED)) {
> > if (!(lock_flags & XFS_ILOCK_SHARED))
> > - return !!ip->i_lock.mr_writer;
> > + return (ip->i_lock.mr_writer != 0);
>
> simpler still would be just removing the !! completely.
> I presume in no case would it make an actual difference
> in emitted code.
>
> ie:
> return ip->i_lock.mr_writer;
Yup, that's exactly what I meant. Casting to a bool type does all
the work of squashing all non-zero values to 1...
Cheers,
Dave.
--
Dave Chinner
david@fromorbit.com
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WARNING: multiple messages have this Message-ID (diff)
From: Dave Chinner <david@fromorbit.com>
To: Joe Perches <joe@perches.com>
Cc: Pranith Kumar <bobby.prani@gmail.com>,
Pranith Kumar <pranith@gatech.edu>,
peterz@infradead.org, linux-kernel@vger.kernel.org,
tim.c.chen@linux.intel.com, davidlohr@hp.com, mingo@redhat.com,
xfs@oss.sgi.com
Subject: Re: [RFC PATCH 1/1] cleanup: use bool as return type for rwsem_is_locked
Date: Sun, 8 Jun 2014 09:44:11 +1000 [thread overview]
Message-ID: <20140607234411.GA9508@dastard> (raw)
In-Reply-To: <1402108770.25112.5.camel@joe-AO725>
On Fri, Jun 06, 2014 at 07:39:30PM -0700, Joe Perches wrote:
> On Fri, 2014-06-06 at 21:41 -0400, Pranith Kumar wrote:
> > On 06/06/2014 08:59 PM, Pranith Kumar wrote:
> > > On 06/06/2014 08:18 PM, Dave Chinner wrote:
> > >> If you are going to change the return type to bool, then you should
> > >> also remove the manual "!!" conversions to a boolean return and let
> > >> the compiler do it in the most optimal way.
> > > Agreed, please find patch below:
> > Simplify the "!!" condition. This is much simpler. :)
> []
> > diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c
>
> > @@ -285,25 +285,25 @@ xfs_ilock_demote(
> > }
> >
> > #if defined(DEBUG) || defined(XFS_WARN)
> > -int
> > +bool
> > xfs_isilocked(
> > xfs_inode_t *ip,
> > uint lock_flags)
> > {
> > if (lock_flags & (XFS_ILOCK_EXCL|XFS_ILOCK_SHARED)) {
> > if (!(lock_flags & XFS_ILOCK_SHARED))
> > - return !!ip->i_lock.mr_writer;
> > + return (ip->i_lock.mr_writer != 0);
>
> simpler still would be just removing the !! completely.
> I presume in no case would it make an actual difference
> in emitted code.
>
> ie:
> return ip->i_lock.mr_writer;
Yup, that's exactly what I meant. Casting to a bool type does all
the work of squashing all non-zero values to 1...
Cheers,
Dave.
--
Dave Chinner
david@fromorbit.com
next prev parent reply other threads:[~2014-06-07 23:44 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-06-05 20:49 [RFC PATCH 1/1] cleanup: use bool as return type for rwsem_is_locked Pranith Kumar
2014-06-06 7:35 ` Peter Zijlstra
2014-06-06 17:53 ` Pranith Kumar
2014-06-06 17:56 ` Peter Zijlstra
2014-06-06 18:02 ` Pranith Kumar
2014-06-06 18:41 ` Davidlohr Bueso
2014-06-06 18:52 ` Pranith Kumar
2014-06-06 18:11 ` Pranith Kumar
2014-06-06 18:11 ` Pranith Kumar
2014-06-07 0:18 ` Dave Chinner
2014-06-07 0:18 ` Dave Chinner
2014-06-07 0:59 ` Pranith Kumar
2014-06-07 0:59 ` Pranith Kumar
2014-06-07 1:41 ` Pranith Kumar
2014-06-07 1:41 ` Pranith Kumar
2014-06-07 2:39 ` Joe Perches
2014-06-07 2:39 ` Joe Perches
2014-06-07 23:44 ` Dave Chinner [this message]
2014-06-07 23:44 ` Dave Chinner
2014-06-08 2:57 ` Pranith Kumar
2014-06-08 2:57 ` Pranith Kumar
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