From: Nick Piggin <npiggin@suse.de>
To: Anton Blanchard <anton@samba.org>
Cc: linuxppc-dev@ozlabs.org
Subject: Re: [PATCH 4/6] powerpc: Rename LWSYNC_ON_SMP to PPC_RELEASE_BARRIER, ISYNC_ON_SMP to PPC_ACQUIRE_BARRIER
Date: Fri, 19 Mar 2010 12:08:13 +1100 [thread overview]
Message-ID: <20100319010813.GF25636@laptop> (raw)
In-Reply-To: <20100210110406.GD3399@kryten>
On Wed, Feb 10, 2010 at 10:04:06PM +1100, Anton Blanchard wrote:
>
> For performance reasons we are about to change ISYNC_ON_SMP to sometimes be
> lwsync. Now that the macro name doesn't make sense, change it and LWSYNC_ON_SMP
> to better explain what the barriers are doing.
>
> Signed-off-by: Anton Blanchard <anton@samba.org>
> ---
>
> Index: powerpc.git/arch/powerpc/include/asm/atomic.h
> ===================================================================
> --- powerpc.git.orig/arch/powerpc/include/asm/atomic.h 2010-02-10 17:12:30.264322204 +1100
> +++ powerpc.git/arch/powerpc/include/asm/atomic.h 2010-02-10 17:13:05.355571902 +1100
> @@ -49,13 +49,13 @@ static __inline__ int atomic_add_return(
> int t;
>
> __asm__ __volatile__(
> - LWSYNC_ON_SMP
> + PPC_RELEASE_BARRIER
> "1: lwarx %0,0,%2 # atomic_add_return\n\
> add %0,%1,%0\n"
> PPC405_ERR77(0,%2)
> " stwcx. %0,0,%2 \n\
> bne- 1b"
> - ISYNC_ON_SMP
> + PPC_ACQUIRE_BARRIER
I wonder if this shouldn't be called PPC_ISYNC_ACQUIRE_BARRIER ?
Unlike PPC_RELEASE_BARRIER, it is not an acquire barrier unless it
is used like an isync.
next prev parent reply other threads:[~2010-03-19 1:08 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-02-10 10:57 [PATCH 1/6] powerpc: Use lwarx hint in spinlocks Anton Blanchard
2010-02-10 11:02 ` [PATCH 2/6] powerpc: Use lwarx/ldarx hint in bit locks Anton Blanchard
2010-02-10 11:03 ` [PATCH 3/6] powerpc: Convert open coded native hashtable bit lock Anton Blanchard
2010-02-10 11:04 ` [PATCH 4/6] powerpc: Rename LWSYNC_ON_SMP to PPC_RELEASE_BARRIER, ISYNC_ON_SMP to PPC_ACQUIRE_BARRIER Anton Blanchard
2010-02-10 11:07 ` [PATCH 5/6] powerpc: Fix lwsync patching code on 64bit Anton Blanchard
2010-02-10 11:10 ` [PATCH 6/6] powerpc: Use lwsync for acquire barrier if CPU supports it Anton Blanchard
2010-02-11 7:09 ` Nick Piggin
2010-02-17 9:43 ` Anton Blanchard
2010-02-17 10:41 ` Nick Piggin
2010-02-17 12:12 ` Benjamin Herrenschmidt
2010-02-16 4:22 ` Olof Johansson
2010-02-16 4:19 ` Benjamin Herrenschmidt
2010-02-16 6:07 ` Olof Johansson
2010-03-19 1:08 ` Nick Piggin [this message]
2010-03-19 1:36 ` [PATCH 4/6] powerpc: Rename LWSYNC_ON_SMP to PPC_RELEASE_BARRIER, ISYNC_ON_SMP to PPC_ACQUIRE_BARRIER Benjamin Herrenschmidt
2010-02-11 6:56 ` [PATCH 1/6] powerpc: Use lwarx hint in spinlocks Nick Piggin
2010-02-17 9:37 ` Anton Blanchard
2010-02-17 10:22 ` Nick Piggin
2010-02-16 4:16 ` Olof Johansson
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