Re: new text patching for review

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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
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