The slabtop command shows detailed kernel slab cache information in real time. It displays aggregate statistics for all caches on the top frame and a detailed list beneath.
.Active / Total Objects (% used) : 4022606 / 4075871 (98.7%)
.Active / Total Slabs (% used) : 108200 / 108200 (100.0%)
.Active / Total Caches (% used) : 87 / 116 (75.0%)
.Active / Total Size (% used) : 931698.02K / 944745.29K (98.6%)
.Minimum / Average / Maximum Object : 0.01K / 0.23K / 16.00K
.
. OBJS ACTIVE USE OBJ SIZE SLABS OBJ/SLAB CACHE SIZE NAME
420960 420960 100% 1.00K 13155 32 420960K xfs_inode
771498 771107 99% 0.19K 36738 21 146952K dentry
135018 128584 95% 0.59K 5193 26 83088K proc_inode_cache
116900 114734 98% 0.57K 4175 28 66800K radix_tree_node
955072 950316 99% 0.06K 14923 64 59692K kmalloc64
581604 574153 98% 0.08K 11404 51 45616K AcpiState
287976 285123 99% 0.10K 7384 39 29536K buffer_head
101478 101478 100% 0.15K 3903 26 15612K xfs_ili
.19401 19349 99% 0.54K 669 29 10704K inode_cache
.23940 23719 99% 0.38K 1140 21 9120K mnt_cache
.41866 38205 91% 0.18K 1903 22 7612K vm_area_struct
.19072 16103 84% 0.25K 596 32 4768K kmalloc256
142592 137537 96% 0.03K 1114 128 4456K kmalloc32
.36142 34506 95% 0.12K 1063 34 4252K kernfs_node_cache
..4650 4131 88% 0.62K 186 25 2976K shmem_inode_cache
122740 122740 100% 0.02K 722 170 2888K scsi_data_buffer
…720 593 82% 4.00K 90 8 2880K kmalloc4096
..2752 2526 91% 1.00K 86 32 2752K kmalloc1024
..1248 1073 85% 2.00K 78 16 2496K kmalloc2048
…900 781 86% 2.47K 75 12 2400K task_struct
..9975 8711 87% 0.19K 475 21 1900K kmalloc192
.16107 15582 96% 0.10K 413 39 1652K blkdev_ioc
…720 720 100% 2.05K 48 15 1536K idr_layer_cache
.11808 10668 90% 0.12K 369 32 1476K kmalloc128
..2944 2724 92% 0.50K 92 32 1472K kmalloc512
..3132 2807 89% 0.44K 87 36 1392K i915_gem_object
.14196 14196 100% 0.09K 338 42 1352K kmalloc96
.16524 14770 89% 0.08K 324 51 1296K anon_vma
…570 506 88% 2.06K 38 15 1216K sighand_cache
.73216 70964 96% 0.02K 286 256 1144K kmalloc16
..1365 946 69% 0.81K 35 39 1120K task_xstate
…136 130 95% 8.00K 34 4 1088K kmalloc8192
..1152 1020 88% 0.88K 32 36 1024K RAW
..1500 1379 91% 0.62K 60 25 960K sock_inode_cache
…784 653 83% 1.12K 28 28 896K signal_cache
.97280 97280 100% 0.01K 190 512 760K kmalloc8
…512 512 100% 0.98K 16 32 512K ext4_inode_cache
…224 164 73% 2.00K 14 16 448K TCP
..5768 5709 98% 0.07K 103 56 412K AcpiParseExt
..3240 3240 100% 0.11K 90 36 360K Netatop_sockinfo
..1435 1435 100% 0.23K 41 35 328K cfq_queue
…312 59 18% 0.81K 8 39 256K bdev_cache
…272 272 100% 0.94K 8 34 256K UDP
…240 240 100% 1.06K 8 30 256K UDPv6
..5100 5015 98% 0.05K 60 85 240K ftrace_event_field
…750 654 87% 0.31K 30 25 240K nf_conntrack_ffffffff81cfa400
…210 210 100% 1.06K 7 30 224K dmaengineunmap128
…112 32 28% 1.90K 7 16 224K blkdev_queue
..5100 5100 100% 0.04K 50 102 200K AcpiNamespace
…300 300 100% 0.62K 12 25 192K files_cache
….42 21 50% 4.44K 6 7 192K net_namespace
..1932 1862 96% 0.09K 42 46 168K ftrace_event_file
…420 380 90% 0.39K 21 20 168K xfs_efd_item
….70 56 80% 2.17K 5 14 160K pid_namespace
…352 288 81% 0.36K 16 22 128K blkdev_requests
The output above is sorted by cache size but it can be changed interactively by pressing:
-
character description header
a number of active objects ACTIVE
b objects per slab OBJ/SLAB
c cache size CACHE SIZE
l number of slabs SLABS
v number of active slabs N/A
n name NAME
o number of objects OBJS
p pages per slab N/A
s object size OBJ SIZE
u cache utilization USE
The default output is interactive and the refresh interval is 3 seconds. From the command line we can change the refresh interval and sort criteria with the -d and -s flags respectively. We can also get the output in a non-interactive manner by sending it to stdout (screen or file) with the -o flag.
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