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Date: Mon, 25 Apr 2005 13:07:52 -0400
From: "Jim C. Brown" <jma5@umd.edu>
Subject: Re: [Qemu-devel] [patch] option -no-tsc for i386 with speedstep
Message-ID: <20050425170752.GA20078@jbrown.mylinuxbox.org>
References: <20050425111532.GA2554@dizzy.ath.cx>
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To: qemu-devel@nongnu.org, dz@debian.org

On Mon, Apr 25, 2005 at 01:15:32PM +0200, Massimo Dal Zotto wrote:
> The patch works for me but I don't know if this is the best way of fixing
> this bug. If anyone has a better suggestion it is welcome.
> 
> -- 
> Massimo Dal Zotto <dz@debian.org>

I just want to point out that your patches break qemu for almost every platform
other than i386.

> +#ifdef __i386__
> +static int notsc = 0;
> +extern int64_t get_clock(void);
> +#endif

> @@ -502,6 +506,9 @@
>  int64_t cpu_get_real_ticks(void)
>  {
>      int64_t val;
> +    if (notsc) {
> +	return get_clock();
> +    }
>      asm volatile ("rdtsc" : "=A" (val));
>      return val;
>  }

You probably want to do this, because notsc is only declared for the i386
platform.

 int64_t cpu_get_real_ticks(void)
 {
     int64_t val;
+#ifdef __i386__
+    if (notsc) {
+	return get_clock();
+    }
+#endif
     asm volatile ("rdtsc" : "=A" (val));
     return val;
 }

-- 
Infinite complexity begets infinite beauty.
Infinite precision begets infinite perfection.