我们有一个 EC2 实例，容量非常大（50+GB）目录项缓存并且大部分都在使用中（99%）。 “drop_cache”命令（sysctl -w vm.drop_caches=2或sysctl -w vm.drop_caches=3）没有多大帮助，因为几乎所有命令都在使用中。有什么方法可以找出这个大型正在使用的目录项缓存中的内容或确定导致它的原因吗？
$ cat /proc/meminfo
MemTotal: 64461192 kB
MemFree: 8585000 kB
MemAvailable: 62782360 kB
Buffers: 194872 kB
Cached: 1956268 kB
SwapCached: 0 kB
Active: 1345168 kB
Inactive: 1161952 kB
Active(anon): 432384 kB
Inactive(anon): 55304 kB
Active(file): 912784 kB
Inactive(file): 1106648 kB
Unevictable: 180872 kB
Mlocked: 180872 kB
SwapTotal: 0 kB
SwapFree: 0 kB
Dirty: 660 kB
Writeback: 0 kB
AnonPages: 536000 kB
Mapped: 241356 kB
Shmem: 58028 kB
KReclaimable: 52894088 kB
Slab: 52981812 kB
SReclaimable: 52894088 kB
SUnreclaim: 87724 kB
KernelStack: 7888 kB
PageTables: 9700 kB
NFS_Unstable: 0 kB
Bounce: 0 kB
WritebackTmp: 0 kB
CommitLimit: 32230596 kB
Committed_AS: 3014752 kB
VmallocTotal: 34359738367 kB
VmallocUsed: 0 kB
VmallocChunk: 0 kB
Percpu: 3520 kB
HardwareCorrupted: 0 kB
AnonHugePages: 274432 kB
ShmemHugePages: 0 kB
ShmemPmdMapped: 0 kB
HugePages_Total: 0
HugePages_Free: 0
HugePages_Rsvd: 0
HugePages_Surp: 0
Hugepagesize: 2048 kB
Hugetlb: 0 kB
DirectMap4k: 1101796 kB
DirectMap2M: 35117056 kB
DirectMap1G: 29360128 kB
$ slabtop -o
Active / Total Objects (% used) : 280524292 / 280718042 (99.9%)
Active / Total Slabs (% used) : 6648104 / 6648104 (100.0%)
Active / Total Caches (% used) : 106 / 145 (73.1%)
Active / Total Size (% used) : 52133002.99K / 52158079.36K (100.0%)
Minimum / Average / Maximum Object : 0.01K / 0.19K / 8.00K
OBJS ACTIVE USE OBJ SIZE SLABS OBJ/SLAB CACHE SIZE NAME
276062010 276061880 99% 0.19K 6572905 42 52583240K dentry
3012800 2962891 98% 0.06K 47075 64 188300K kmalloc-rcl-64
537147 427803 79% 0.10K 13773 39 55092K buffer_head
214710 213860 99% 0.02K 1263 170 5052K avtab_node
140288 138299 98% 0.01K 274 512 1096K kmalloc-8
107776 107008 99% 0.02K 421 256 1684K kmalloc-16
97024 93353 96% 0.03K 758 128 3032K kmalloc-32
65688 61376 93% 0.04K 644 102 2576K Acpi-Namespace
40128 38686 96% 0.06K 627 64 2508K kmalloc-64
34304 33033 96% 0.03K 268 128 1072K avc_xperms_data
28140 28140 100% 0.13K 938 30 3752K kernfs_node_cache
27264 26871 98% 0.06K 426 64 1704K ebitmap_node
24300 22497 92% 0.88K 675 36 21600K xfs_inode
23040 23040 100% 0.02K 90 256 360K selinux_file_security
22865 22865 100% 0.05K 269 85 1076K ftrace_event_field
21616 17768 82% 0.57K 772 28 12352K radix_tree_node
$ uname -r
4.20.8-1.el7.elrepo.x86_64