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lscpu 中读取cache 信息的源码如下：https://github.com/karelzak/util-linux/blob/master/sys-utils/lscpu.c下面这段code 中主要从/sys/devices/system/cpu/cpu0/cache/index0 这个文件系统中查找cache信息，包含cache的type.level,sizeread_cache(struct lscpu_desc *desc, int idx){	char buf[256];	int i;	int num = real_cpu_num(desc, idx);	if (!desc->ncaches) {		while (ul_path_accessf(desc->syscpu, F_OK,					"cpu%d/cache/index%d",					num, desc->ncaches) == 0)			desc->ncaches++;		if (!desc->ncaches)			return;		desc->caches = xcalloc(desc->ncaches, sizeof(*desc->caches));	}	for (i = 0; i < desc->ncaches; i++) {		struct cpu_cache *ca = &desc->caches[i];		cpu_set_t *map;		if (ul_path_accessf(desc->syscpu, F_OK,					"cpu%d/cache/index%d", num, i) != 0)			continue;		if (!ca->name) {			int type = 0, level;			/* cache type */			if (ul_path_readf_buffer(desc->syscpu, buf, sizeof(buf),					"cpu%d/cache/index%d/type", num, i) > 0) {				if (!strcmp(buf, "Data"))					type = 'd';				else if (!strcmp(buf, "Instruction"))					type = 'i';			}			/* cache level */			ul_path_readf_s32(desc->syscpu, &level,					"cpu%d/cache/index%d/level", num, i);			if (type)				snprintf(buf, sizeof(buf), "L%d%c", level, type);			else				snprintf(buf, sizeof(buf), "L%d", level);			ca->name = xstrdup(buf);			/* cache size */			if (ul_path_readf_string(desc->syscpu, &ca->size,					"cpu%d/cache/index%d/size", num, i) < 0)				ca->size = xstrdup("unknown size");		}		/* information about how CPUs share different caches */		ul_path_readf_cpuset(desc->syscpu, &map, maxcpus,				  "cpu%d/cache/index%d/shared_cpu_map", num, i);		if (!ca->sharedmaps)			ca->sharedmaps = xcalloc(desc->ncpuspos, sizeof(cpu_set_t *));		add_cpuset_to_array(ca->sharedmaps, &ca->nsharedmaps, map);	}}与之对应的os中实现/sys/devices/system/cpu/cpu0/cache/index0/ 这个sysfs文件系统对应的源码在driver/base/cacheinfo.c show_one(id, id);show_one(level, level);show_one(coherency_line_size, coherency_line_size);可以看到这里实现了读取cache的id/level/size.与之对应的文件系统得到的结果如下：tiantao@BoardServer2:/sys/devices/system/cpu/cpu0/cache/index0$ lscoherency_line_size  level  number_of_sets  physical_line_partition  power  shared_cpu_list  shared_cpu_map  size  type  uevent  ways_of_associativitytiantao@BoardServer2:/sys/devices/system/cpu/cpu0/cache/index0$ cat typeDatatiantao@BoardServer2:/sys/devices/system/cpu/cpu0/cache/index0$ cat level1tiantao@BoardServer2:/sys/devices/system/cpu/cpu0/cache/index0$ cat coherency_line_size64tiantao@BoardServer2:/sys/devices/system/cpu/cpu0/cache/index0$从这里可以知道L1的data cache size是64

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