在linux系统中可以通过/proc/slabinfo获取slab的统计数据，crash提供了kmem来实现这个功能。
查看系统每个kmem_cache的概要信息
crash> kmem -s CACHE OBJSIZE ALLOCATED TOTAL SLABS SSIZE NAME ffff888141e12000 131072 0 0 0 128k 9p-fcall-cache ffff888140834f00 312 800 806 31 8k ext4_groupinfo_4k ffff888140834e00 216 0 216 6 8k p9_req_t ffff888140834d00 304 0 0 0 8k ip6-frags ffff888140834c00 1984 0 32 2 32k UDPv6 ffff888140834b00 312 0 0 0 8k tw_sock_TCPv6 ffff888140834a00 352 0 0 0 8k request_sock_TCPv6 ffff888140834900 3176 3 20 2 32k TCPv6 ... ffff888005842900 256 1348 1696 53 8k kmalloc-256 ffff888005842800 192 1014 2961 141 4k kmalloc-192 ffff888005842700 128 883 1184 37 4k kmalloc-128 ffff888005842600 96 664 1806 43 4k kmalloc-96 ffff888005842500 64 4175 4992 78 4k kmalloc-64 ffff888005842400 32 3387 4480 35 4k kmalloc-32 ffff888005842300 16 2436 3840 15 4k kmalloc-16 ffff888005842200 8 2283 5120 10 4k kmalloc-8 ffff888005842100 128 652 864 27 4k kmem_cache_node ffff888005842000 224 163 288 9 8k kmem_cache
查看某个kmem_cache的详细信息
比如想查看kmalloc-8k为例：
crash> kmem -S kmalloc-8k CACHE OBJSIZE ALLOCATED TOTAL SLABS SSIZE NAME ffff888005842e00 8192 33 60 15 32k kmalloc-8k CPU 0 KMEM_CACHE_CPU: ffff88807f802db0 CPU 0 SLAB: SLAB MEMORY NODE TOTAL ALLOCATED FREE ffffea000019ba00 ffff8880066e8000 0 4 0 4 FREE / [ALLOCATED] ffff8880066e8000 (cpu 0 cache) ffff8880066ea000 (cpu 0 cache) ffff8880066ec000 (cpu 0 cache) ffff8880066ee000 (cpu 0 cache) CPU 0 PARTIAL: (empty) CPU 1 KMEM_CACHE_CPU: ffff88807fc02db0 CPU 1 SLAB: (empty) CPU 1 PARTIAL: (empty) CPU 2 KMEM_CACHE_CPU: ffff88813d802db0 CPU 2 SLAB: SLAB MEMORY NODE TOTAL ALLOCATED FREE ffffea0004068600 ffff888101a18000 1 4 2 2 FREE / [ALLOCATED] [ffff888101a18000] [ffff888101a1a000] ffff888101a1c000 (cpu 2 cache) ffff888101a1e000 (cpu 2 cache) CPU 2 PARTIAL: (empty) CPU 3 KMEM_CACHE_CPU: ffff88813dc02db0 CPU 3 SLAB: SLAB MEMORY NODE TOTAL ALLOCATED FREE ffffea0004108200 ffff888104208000 1 4 0 4 FREE / [ALLOCATED] ffff888104208000 (cpu 3 cache) ffff88810420a000 (cpu 3 cache) ffff88810420c000 (cpu 3 cache) ffff88810420e000 (cpu 3 cache) CPU 3 PARTIAL: (empty) ... KMEM_CACHE_NODE NODE SLABS PARTIAL PER-CPU ffff888005840700 0 3 1 1 NODE 0 PARTIAL: SLAB MEMORY NODE TOTAL ALLOCATED FREE ffffea00001f7e00 ffff888007df8000 0 4 2 2 NODE 0 FULL: (not tracked) KMEM_CACHE_NODE NODE SLABS PARTIAL PER-CPU ffff888100000700 1 2 0 2 NODE 1 PARTIAL: (empty) NODE 1 FULL: (not tracked) KMEM_CACHE_NODE NODE SLABS PARTIAL PER-CPU ffff888140000700 2 3 0 2 NODE 2 PARTIAL: (empty) NODE 2 FULL: (not tracked) KMEM_CACHE_NODE NODE SLABS PARTIAL PER-CPU ffff8881c0000700 3 7 0 2 NODE 3 PARTIAL: (empty) NODE 3 FULL: (not tracked)
