Re: new text patching for review

[Zachary Amsden]

Andi Kleen wrote:
> +	*addr = opcode;
> +	/* Not strictly needed, but can speed CPU recovery up */
> +	if (cpu_has_clflush)
> +		asm("clflush (%0) " :: "r" (addr) : "memory");
> +	if (addr != oaddr)
> +		vunmap(addr);
>   

clflush should take oaddr.

If you had to remap, note that the processor does not know the linear 
address you wrote to could be matched by another mapping in icache.  In 
that case, you'll need a serializing instruction (cpuid) to 
resynchronize caches.

I don't think any of these are SMP problems since either the code is 
patched before AP bringup or it is single byte patching.

Zach
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/