1. 根目录:
2. tools
3. perf
4. util
5. include
6. asm
7. alternative-asm.h

#ifndef _PERF_ASM_ALTERNATIVE_ASM_H
#define _PERF_ASM_ALTERNATIVE_ASM_H

/* Just disable it so we can build arch/x86/lib/memcpy_64.S for perf bench: */

#define altinstruction_entry #

#endif