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Date: Fri, 8 Apr 2016 08:22:50 +0200
From: Michal Hocko <mhocko@kernel.org>
To: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Cc: LKML <linux-kernel@vger.kernel.org>, Peter Zijlstra <peterz@infradead.org>,
        Ingo Molnar <mingo@redhat.com>, Thomas Gleixner <tglx@linutronix.de>,
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Subject: Re: [PATCH 08/11] ia64, rwsem: provide __down_write_killable
Message-ID: <20160408062249.GA29820@dhcp22.suse.cz>
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 <570698B0.8090707@cogentembedded.com>
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On Thu 07-04-16 20:28:16, Sergei Shtylyov wrote:
> Hello.
> 
> On 04/07/2016 06:12 PM, Michal Hocko wrote:
> 
> >From: Michal Hocko <mhocko@suse.com>
> >
> >Introduce ___down_write for the fast path and reuse it for __down_write
> >resp. __down_write_killable each using the respective generic slow path
> >(rwsem_down_write_failed resp. rwsem_down_write_failed_killable).
> >
> >Signed-off-by: Michal Hocko <mhocko@suse.com>
> >---
> >  arch/ia64/include/asm/rwsem.h | 22 +++++++++++++++++++---
> >  1 file changed, 19 insertions(+), 3 deletions(-)
> >
> >diff --git a/arch/ia64/include/asm/rwsem.h b/arch/ia64/include/asm/rwsem.h
> >index 3027e7516d85..5e78cb40d9df 100644
> >--- a/arch/ia64/include/asm/rwsem.h
> >+++ b/arch/ia64/include/asm/rwsem.h
> >@@ -49,8 +49,8 @@ __down_read (struct rw_semaphore *sem)
> >  /*
> >   * lock for writing
> >   */
> >-static inline void
> >-__down_write (struct rw_semaphore *sem)
> >+static inline long
> >+___down_write (struct rw_semaphore *sem)
> >  {
> >  	long old, new;
> >
> >@@ -59,10 +59,26 @@ __down_write (struct rw_semaphore *sem)
> >  		new = old + RWSEM_ACTIVE_WRITE_BIAS;
> >  	} while (cmpxchg_acq(&sem->count, old, new) != old);
> >
> >-	if (old != 0)
> >+	return old;
> >+}
> >+
> >+static inline void
> >+__down_write (struct rw_semaphore *sem)
> >+{
> >+	if (___down_write(sem))
> >  		rwsem_down_write_failed(sem);
> >  }
> >
> >+static inline int
> >+__down_write_killable (struct rw_semaphore *sem)
> 
>    Looks like you haven't run this patch thru scripts/checkpatch.pl. Hint:
> space before ( isn't allowed.

I have just kept the original code styling because I didn't feel like
changing the whole file.

-- 
Michal Hocko
SUSE Labs