From: Joel Schopp <jschopp@austin.ibm.com>
To: Nick Piggin <npiggin@suse.de>
Cc: linuxppc-dev@ozlabs.org, Paul Mackerras <paulus@samba.org>
Subject: Re: [patch 1/2] powerpc: rmb fix
Date: Tue, 21 Aug 2007 14:07:00 -0500 [thread overview]
Message-ID: <46CB37D4.2080609@austin.ibm.com> (raw)
In-Reply-To: <20070821021143.GB2909@wotan.suse.de>
> #define mb() __asm__ __volatile__ ("sync" : : : "memory")
> -#define rmb() __asm__ __volatile__ (__stringify(LWSYNC) : : : "memory")
> +#define rmb() __asm__ __volatile__ ("sync" : : : "memory")
> #define wmb() __asm__ __volatile__ ("sync" : : : "memory")
> #define read_barrier_depends() do { } while(0)
>
> @@ -42,7 +42,7 @@
> #ifdef __KERNEL__
> #ifdef CONFIG_SMP
> #define smp_mb() mb()
> -#define smp_rmb() rmb()
> +#define smp_rmb() __asm__ __volatile__ (__stringify(LWSYNC) : : : "memory")
> #define smp_wmb() eieio()
> #define smp_read_barrier_depends() read_barrier_depends()
> #else
I had to think about this one for awhile. It looks at first glance to be the right
thing to do. But I do wonder how long rmb() has been lwsync and if as a practical
matter that has caused any problems? If this isn't causing any problems maybe there
is some loigic we are overlooking?
next prev parent reply other threads:[~2007-08-21 19:07 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-08-21 2:11 [patch 1/2] powerpc: rmb fix Nick Piggin
2007-08-21 2:16 ` [patch 1/2] powerpc: smp_wmb speedup Nick Piggin
2007-08-21 2:21 ` Nick Piggin
2007-08-21 19:07 ` Joel Schopp [this message]
2007-08-21 19:43 ` [patch 1/2] powerpc: rmb fix Segher Boessenkool
2007-08-21 21:42 ` Linas Vepstas
2007-08-22 1:16 ` Nick Piggin
2007-08-22 3:29 ` Segher Boessenkool
2007-08-22 3:55 ` Nick Piggin
2007-08-23 17:57 ` Segher Boessenkool
2007-08-24 2:47 ` Nick Piggin
2007-08-22 3:15 ` Nick Piggin
2007-08-22 3:33 ` Segher Boessenkool
2007-08-22 4:05 ` Nick Piggin
2007-08-23 17:49 ` Segher Boessenkool
-- strict thread matches above, loose matches on Subject: below --
2008-05-21 14:10 Nick Piggin
2008-05-21 15:27 ` Benjamin Herrenschmidt
2008-05-21 15:32 ` Nick Piggin
2008-05-21 15:43 ` Benjamin Herrenschmidt
2008-05-23 2:14 ` Paul Mackerras
2008-05-23 4:40 ` Nick Piggin
2008-05-23 4:53 ` Paul Mackerras
2008-05-23 5:48 ` Nick Piggin
2008-05-23 6:40 ` Paul Mackerras
2008-05-26 1:38 ` Nick Piggin
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