From mboxrd@z Thu Jan  1 00:00:00 1970
From: Thomas Steudten <alpha@steudten.com>
Subject: Re: SOLVED: BUG: Kernel Panic: kernel-2.6.0-test9-bk21  for alpha
 in scsi context ll_rw_blk.c
Date: Tue, 18 Nov 2003 22:29:04 +0100
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To: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Falk Hueffner <falk.hueffner@student.uni-tuebingen.de>, Richard Henderson <rth@twiddle.net>, linux-kernel@vger.kernel.org, linux-scsi@vger.kernel.org, linux-alpha@vger.kernel.org, akpm@osdl.org

Hi

With the patch from Ivan, the prefetch problem is gone.
Please add this patch to the mainline for 2.6.0 for alpha.

Regards
Tom

> We shouldn't prefetch the spinlocks on UP.
> 
> Ivan.
> 
> --- 2.6/include/asm-alpha/processor.h	Sat Oct 25 22:44:54 2003
> +++ linux/include/asm-alpha/processor.h	Tue Nov 18 01:48:39 2003
> @@ -78,6 +78,11 @@ unsigned long get_wchan(struct task_stru
>  #define ARCH_HAS_PREFETCHW
>  #define ARCH_HAS_SPINLOCK_PREFETCH
>  
> +#ifndef CONFIG_SMP
> +/* Nothing to prefetch. */
> +#define spin_lock_prefetch(lock)  	do { } while (0)
> +#endif
> +
>  #if __GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ >= 1)
>  extern inline void prefetch(const void *ptr)  
>  { 
> @@ -89,10 +94,13 @@ extern inline void prefetchw(const void 
>  	__builtin_prefetch(ptr, 1, 3);
>  }
>  
> +#ifdef CONFIG_SMP
>  extern inline void spin_lock_prefetch(const void *ptr)  
>  {
>  	__builtin_prefetch(ptr, 1, 3);
>  }
> +#endif
> +
>  #else
>  extern inline void prefetch(const void *ptr)  
>  { 
> @@ -104,10 +112,13 @@ extern inline void prefetchw(const void 
>  	__asm__ ("ldq $31,%0" : : "m"(*(char *)ptr)); 
>  }
>  
> +#ifdef CONFIG_SMP
>  extern inline void spin_lock_prefetch(const void *ptr)  
>  {
>  	__asm__ ("ldq $31,%0" : : "m"(*(char *)ptr)); 
>  }
> +#endif
> +
>  #endif /* GCC 3.1 */
>  
>  #endif /* __ASM_ALPHA_PROCESSOR_H */

-- 
Tom

LINUX user since kernel 0.99.x 1994.
RPM Alpha packages at http://alpha.steudten.com/packages
Want to know what S.u.S.E 1995 cdrom-set contains?