if (old != new) force_flush_all(); 
static inline void activate_mm(struct mm_struct *old, struct mm_struct *new){}
4520	/local/tlutelli/issta_data/temp/c/2005_temp/2005/4520/c40504e87e28c52258458a53fefcd63f58e11a42/mmu_context.h/buggy/include/asm-um/mmu_context.h