Re: SMP Athlon...(a quiet question)

Tom Leete (tleete@mountain.net)
Sat, 27 Jan 2001 20:36:53 -0500


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Andre Hedrick wrote:
>
> ER, they work but must compile as PII/Celeron :-(
> A bunch of memcpy header stuff fails to compile....
> current is one of the left overs in some cases.
>
> I will dive deeper in monday, just wanting some feed back first.
>
> Cheers,
>
> Andre Hedrick
> Linux ATA Development
>
> -
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Hello Andre,

I think that there is no good way to use in_interrupt() in asm/string.h.
Circular dependencies.

I've been using some form of this patch since last May, posted here several
times. It moves the mmx style memcpy into lib.a (mmx.c). I lose some
inlining, but since k7 does branch prediction for call addresses, inline
functions are somewhat less of a win. Certainly the big speedup from mmx is
more than enough to pay for it.

Cheers,
Tom

-- 
The Daemons lurk and are dumb. -- Emerson
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--- linux/arch/i386/lib/mmx.c.orig Wed Oct 27 21:30:39 1999 +++ linux/arch/i386/lib/mmx.c Tue Jun 6 04:20:01 2000 @@ -1,6 +1,7 @@ #include <linux/types.h> #include <linux/string.h> #include <linux/sched.h> +#include <asm/hardirq.h> /* * MMX 3DNow! library helper functions @@ -88,6 +89,21 @@ stts(); return p; } + +void * __constant_mmx_memcpy3d(void * to, const void * from, size_t len) +{ + if(in_interrupt()) + return __constant_memcpy(to, from, len); + return _mmx_memcpy(to, from, len); +} + +void *__mmx_memcpy3d(void *to, const void *from, size_t len) +{ + if(in_interrupt()) + return __memcpy(to, from, len); + return _mmx_memcpy(to, from, len); +} + static void fast_clear_page(void *page) { --- linux/include/asm-i386/mmx.h.orig Tue Jun 6 03:05:02 2000 +++ linux/include/asm-i386/mmx.h Tue Jun 6 04:25:27 2000 @@ -10,5 +10,7 @@ extern void *_mmx_memcpy(void *to, const void *from, size_t size); extern void mmx_clear_page(void *page); extern void mmx_copy_page(void *to, void *from); +extern __inline__ void *__constant_mmx_memcpy3d(void * to, const void * from, size_t len); +extern __inline__ void *__mmx_memcpy3d(void *to, const void *from, size_t len); #endif --- linux/include/asm-i386/string.h.orig Tue Jun 6 03:05:02 2000 +++ linux/include/asm-i386/string.h Tue Jun 6 04:30:37 2000 @@ -287,13 +287,6 @@ #ifdef CONFIG_X86_USE_3DNOW -/* All this just for in_interrupt() ... */ - -#include <asm/system.h> -#include <asm/ptrace.h> -#include <linux/smp.h> -#include <linux/spinlock.h> -#include <linux/interrupt.h> #include <asm/mmx.h> /* @@ -302,16 +295,16 @@ static inline void * __constant_memcpy3d(void * to, const void * from, size_t len) { - if(len<512 || in_interrupt()) + if(len<512) return __constant_memcpy(to, from, len); - return _mmx_memcpy(to, from, len); + return __constant_mmx_memcpy3d(to, from, len); } extern __inline__ void *__memcpy3d(void *to, const void *from, size_t len) { - if(len<512 || in_interrupt()) + if(len<512) return __memcpy(to, from, len); - return _mmx_memcpy(to, from, len); + return __mmx_memcpy3d(to, from, len); } #define memcpy(t, f, n) \

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