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如何在Linux中刷新地址空间区域的CPU缓存?

linux

我只对地址空间的某个区域刷新缓存(L1,L2和L3)感兴趣,例如从地址A到地址B的所有缓存条目。在Linux中,有没有一种从用户空间或内核空间进行缓存的机制?


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2020-06-02

共1个答案

小编典典

检查此页面以获取Linux内核中可用的刷新方法列表:https
:
//www.kernel.org/doc/Documentation/cachetlb.txt

Linux下的缓存和TLB刷新。戴维·米勒

有一套范围冲洗功能

2) flush_cache_range(vma, start, end);
   change_range_of_page_tables(mm, start, end);
   flush_tlb_range(vma, start, end);

3)void flush_cache_range(struct vm_area_struct * vma,unsigned long
start,unsigned long end)

Here we are flushing a specific range of (user) virtual
addresses from the cache.  After running, there will be no
entries in the cache for 'vma->vm_mm' for virtual addresses in
the range 'start' to 'end-1'.

您还可以检查该功能的实现-http://lxr.free-
electrons.com/ident?a=sh;i=flush_cache_range

例如,在手臂上-http://lxr.free-
electrons.com/source/arch/arm/mm/flush.c?a=sh&v=3.13#L67

 67 void flush_cache_range(struct vm_area_struct *vma, unsigned long start, unsigned long end)
 68 {
 69         if (cache_is_vivt()) {
 70                 vivt_flush_cache_range(vma, start, end);
 71                 return;
 72         }
 73 
 74         if (cache_is_vipt_aliasing()) {
 75                 asm(    "mcr    p15, 0, %0, c7, c14, 0\n"
 76                 "       mcr     p15, 0, %0, c7, c10, 4"
 77                     :
 78                     : "r" (0)
 79                     : "cc");
 80         }
 81 
 82         if (vma->vm_flags & VM_EXEC)
 83                 __flush_icache_all();
 84 }
2020-06-02