flush_tlb_func\u00a0\u662f x86 \u67b6\u6784 TLB \u5237\u65b0（TLB Shootdown）\u673a\u5236\u4e2d\u7684\u6838\u5fc3 IPI \u5904\u7406\u51fd\u6570\u3002\u5b83\u8fd0\u884c\u5728\u63a5\u6536\u5230\u5237\u65b0\u8bf7\u6c42\u7684\u8fdc\u7a0b CPU \u4e0a，\u8d1f\u8d23\u6839\u636e\u8bf7\u6c42\u4fe1\u606f\u6267\u884c\u672c\u5730 TLB \u5931\u6548\u64cd\u4f5c\u3002<\/p>\n
\u5f53 CPU A \u4fee\u6539\u4e86\u9875\u8868\u540e，\u9700\u8981\u901a\u77e5\u6240\u6709\u6b63\u5728\u4f7f\u7528\u8be5\u5730\u5740\u7a7a\u95f4\u7684 CPU \u5237\u65b0 TLB\u3002\u5b83\u901a\u8fc7\u00a0smp_call_function_many\u00a0\u53d1\u9001 IPI，\u76ee\u6807 CPU \u7684\u4e2d\u65ad\u5904\u7406\u7a0b\u5e8f\u4f1a\u8c03\u7528\u00a0flush_tlb_func，\u5728\u672c\u5730\u6267\u884c\u5b9e\u9645\u7684 TLB \u5931\u6548\u64cd\u4f5c\u3002<\/p>\n
\u6839\u636e\u5185\u6838\u6e90\u7801，\u5176\u903b\u8f91\u53ef\u4ee5\u6982\u62ec\u4e3a\u4ee5\u4e0b\u51e0\u4e2a\u5173\u952e\u9636\u6bb5：<\/p>\n
1. \u5feb\u901f\u68c0\u67e5\u4e0e\u60f0\u6027 TLB \u5904\u7406<\/p>\n
if (f->mm && f->mm != this_cpu_read(cpu_tlbstate.active_mm))
\n return;<\/p>\n
\u5982\u679c\u8bf7\u6c42\u7684\u00a0mm\u00a0\u4e0e\u5f53\u524d CPU \u6d3b\u8dc3\u7684\u00a0mm\u00a0\u4e0d\u5339\u914d，\u8bf4\u660e\u8be5 CPU \u4e0d\u9700\u8981\u5237\u65b0，\u76f4\u63a5\u8fd4\u56de\u3002\u968f\u540e\u68c0\u67e5\u5f53\u524d CPU \u662f\u5426\u5904\u4e8e\u60f0\u6027 TLB \u6a21\u5f0f：\u5982\u679c\u662f，\u5219\u8c03\u7528\u00a0leave_mm()\u00a0\u9000\u51fa\u60f0\u6027\u6a21\u5f0f\u5e76\u5207\u6362\u56de\u00a0init_mm，\u800c\u4e0d\u662f\u7ee7\u7eed\u4f7f\u7528\u53ef\u80fd\u8fc7\u671f\u7684\u9875\u8868\u3002<\/p>\n
2. TLB \u4e16\u4ee3（tlb_gen）\u68c0\u67e5<\/p>\n
u64 mm_tlb_gen = atomic64_read(&loaded_mm->context.tlb_gen);
\nu64 local_tlb_gen = this_cpu_read(cpu_tlbstate.ctxs[loaded_mm_asid].tlb_gen);<\/p>\n
\u5185\u6838\u4e3a\u6bcf\u4e2a\u00a0mm\u00a0\u7ef4\u62a4\u4e00\u4e2a\u5168\u5c40\u9012\u589e\u7684 TLB \u4e16\u4ee3\u8ba1\u6570\u5668\u3002\u6bcf\u4e2a CPU \u8bb0\u5f55\u81ea\u5df1\u5df2\u201c\u8ffd\u8d76\u201d\u5230\u7684\u4e16\u4ee3\u3002\u5982\u679c\u8bf7\u6c42\u7684\u00a0new_tlb_gen <= local_tlb_gen，\u8bf4\u660e\u8be5 CPU \u7684 TLB \u5df2\u7ecf\u662f\u6700\u65b0\u7684，\u53ef\u4ee5\u8df3\u8fc7\u5237\u65b0，\u907f\u514d\u4e0d\u5fc5\u8981\u7684\u5f00\u9500\u3002<\/p>\n
3. \u6267\u884c\u5237\u65b0<\/p>\n
if (f->end == TLB_FLUSH_ALL) {
\n local_flush_tlb();
\n} else {
\n for (addr = f->start; addr < f->end; addr += PAGE_SIZE)
\n __flush_tlb_single(addr);
\n}<\/p>\n
\u6839\u636e\u8bf7\u6c42\u8303\u56f4\u51b3\u5b9a\u5237\u65b0\u7b56\u7565：<\/p>\n
\u5168\u91cf\u5237\u65b0（end == TLB_FLUSH_ALL）：\u8c03\u7528\u00a0local_flush_tlb()，\u901a\u8fc7\u91cd\u5199 CR3 \u6216\u5207\u6362 PGE \u4f4d\u6765\u6e05\u7a7a\u6574\u4e2a TLB\u3002<\/p>\n<\/li>\n
\u8303\u56f4\u5237\u65b0：\u9010\u9875\u8c03\u7528\u00a0__flush_tlb_single(addr)（\u5373\u00a0invlpg\u00a0\u6307\u4ee4），\u7cbe\u786e\u5931\u6548\u6307\u5b9a\u5730\u5740\u7684 TLB \u6761\u76ee\u3002<\/p>\n<\/li>\n<\/ul>\n
4. \u66f4\u65b0\u672c\u5730\u4e16\u4ee3<\/p>\n
\u5237\u65b0\u5b8c\u6210\u540e，\u5c06\u672c CPU \u8bb0\u5f55\u7684\u00a0tlb_gen\u00a0\u66f4\u65b0\u4e3a\u00a0mm_tlb_gen，\u8868\u793a\u5df2\u7ecf\u8ffd\u8d76\u4e0a\u4e86\u6700\u65b0\u7684\u9875\u8868\u72b6\u6001\u3002<\/p>\n
flush_tlb_mm_range() \/ flush_tlb_kernel_range()
\n \u2514\u2500\u2500 native_flush_tlb_others() \/ flush_tlb_multi()
\n \u2514\u2500\u2500 smp_call_function_many(cpumask, flush_tlb_func, info, 1)
\n \u2514\u2500\u2500 flush_tlb_func(info) \/\/ \u2190 \u8fdc\u7a0b CPU \u7684 IPI \u5904\u7406<\/p>\n
flush_tlb_func\u00a0\u4f5c\u4e3a\u00a0smp_call_function_many\u00a0\u7684\u56de\u8c03\u88ab\u8c03\u7528，\u8fd0\u884c\u5728\u4e2d\u65ad\u4e0a\u4e0b\u6587\u4e2d，\u56e0\u6b64\u5fc5\u987b\u6ee1\u8db3：\u4e2d\u65ad\u5df2\u7981\u7528\u3001\u4e0d\u53ef\u91cd\u5165（\u4ee3\u7801\u4e2d\u6709\u00a0VM_WARN_ON(!irqs_disabled())\u00a0\u548c\u91cd\u5165\u68c0\u67e5）\u3002<\/p>\n
\u8fd9\u4e2a\u51fd\u6570\u7ecf\u5386\u8fc7\u591a\u6b21\u4f18\u5316：<\/p>\n
\u5ef6\u8fdf\u8bfb\u53d6\u00a0mm_tlb_gen：2022 \u5e74\u7684\u8865\u4e01\u5c06\u00a0mm_tlb_gen\u00a0\u7684\u8bfb\u53d6\u63a8\u8fdf\u5230\u786e\u8ba4\u9700\u8981\u5237\u65b0\u4e4b\u540e，\u907f\u514d\u5728\u5237\u65b0\u98ce\u66b4\u4e2d\u4e89\u62a2\u00a0mm\u00a0\u7ed3\u6784\u4f53\u7684\u7f13\u5b58\u884c，\u5728 56 \u6838 Skylake \u4e0a\u5e26\u6765\u9ad8\u8fbe\u00a024%\u00a0\u7684\u6027\u80fd\u63d0\u5347\u3002<\/p>\n<\/li>\n
\u8df3\u8fc7\u65e0\u610f\u4e49\u7684\u8ddf\u8e2a：2022 \u5e74\u7684\u8865\u4e01\u786e\u4fdd\u5728\u201c\u4e0d\u6267\u884c\u5237\u65b0\u201d\u7684\u8def\u5f84\u4e0a\u4e0d\u8c03\u7528\u00a0trace_tlb_flush，\u4fdd\u6301\u8ddf\u8e2a\u884c\u4e3a\u4e00\u81f4\u3002<\/p>\n<\/li>\n
\u9608\u503c\u51b3\u7b56\u96c6\u4e2d\u5316：2025 \u5e74\u7684\u8865\u4e01\u5c06\u201c\u90e8\u5206\u5237\u65b0\u8fd8\u662f\u5168\u91cf\u5237\u65b0\u201d\u7684\u51b3\u7b56\u96c6\u4e2d\u5230\u00a0get_flush_tlb_info\u4e2d，\u51cf\u5c11\u4ee3\u7801\u91cd\u590d\u3002<\/p>\n<\/li>\n<\/ul>\n","protected":false},"excerpt":{"rendered":"
flush_tlb_func\u00a0\u662f x86 \u67b6\u6784 TLB \u5237\u65b0（TLB Shootdown）\u673a\u5236\u4e2d\u7684\u6838\u5fc3 IPI \u5904\u7406\u51fd\u6570\u3002\u5b83\u8fd0\u884c\u5728\u63a5\u6536\u5230\u5237\u65b0\u8bf7\u6c42\u7684\u8fdc\u7a0b CPU \u4e0a，\u8d1f\u8d23\u6839\u636e\u8bf7\u6c42\u4fe1\u606f\u6267\u884c\u672c\u5730 TLB \u5931\u6548\u64cd\u4f5c\u3002\u6838\u5fc3\u4f5c\u7528：\u8fdc\u7a0b TLB \u5931\u6548\u6267\u884c\u8005\u5f53 CPU A \u4fee\u6539\u4e86\u9875\u8868\u540e，\u9700\u8981\u901a\u77e5\u6240\u6709\u6b63\u5728\u4f7f\u7528\u8be5\u5730\u5740\u7a7a\u95f4\u7684 CPU \u5237\u65b0 TLB\u3002\u5b83\u901a\u8fc7\u00a0smp_call_function_many\u00a0\u53d1\u9001 IPI，<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[58],"topic":[],"class_list":["post-112038","post","type-post","status-publish","format-standard","hentry","category-server","tag-linux"],"yoast_head":"\n