Re: [PATCH] ftrace: use only 5 byte nops for x86

From: H. Peter Anvin
Date: Fri Aug 15 2008 - 19:00:32 EST


Linus Torvalds wrote:

I think what we need to do is to test the NOPL instruction and create a
Linux-specific CPUID bit for it. I'll do that and submit to tip:x86/cpu.

I also suspect that we'd really be much better off just fixing the generic NOP tables for the 5-byte nop. As far as I could tell, from all the numbers that have been posted, absolutely _none_ show that there is any point at all to the 2-instruction 3/2-byte sequence.

So instead of having a magic special ftrace-only thing, why not just do it right, and fix the generic 5-byte nop sequence?


There is that, too. The two are orthogonal.

-hpa
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