/proc和内存管理 相关的内容
本文平台是 x86虚拟云服务器，kernel版本时 4.15
主要分析以下几个文件节点信息
sh@tencent_cloud:/ $ ls /proc/ |grep info
buddyinfo #伙伴系统信息
cpuinfo #cpu硬件相关信息
meminfo #内存总览信息
pagetypeinfo #伙伴系统信息,比buddyinfo更加详细
slabinfo #slab分配器当前情况
vmallocinfo #vmalloc分配器相关信息
zoneinfo #zone节点信息
meminfo
/proc/meminfo 是系统中 汇总的 内存信息
sh@tencent_cloud:/ $ sudo cat /proc/meminfo
MemTotal: 1877504 kB #系统中有的总共内存
MemFree: 350448 kB #系统中空闲的内存
MemAvailable: 1007712 kB #系统中可获得内存一般 <= Memfree + Buffers + Cached
Buffers: 207976 kB
Cached: 464604 kB
SwapCached: 52812 kB
Active: 689112 kB
Inactive: 501844 kB
Active(anon): 252108 kB
Inactive(anon): 280312 kB
Active(file): 437004 kB
Inactive(file): 221532 kB
Unevictable: 0 kB
Mlocked: 0 kB
SwapTotal: 1049596 kB
SwapFree: 576764 kB
Dirty: 696 kB
Writeback: 0 kB
AnonPages: 509408 kB
Mapped: 132704 kB
Shmem: 14016 kB
Slab: 260092 kB
SReclaimable: 185924 kB
SUnreclaim: 74168 kB
KernelStack: 6752 kB
PageTables: 30656 kB
NFS_Unstable: 0 kB
Bounce: 0 kB
WritebackTmp: 0 kB
CommitLimit: 1988348 kB
Committed_AS: 3351132 kB
VmallocTotal: 34359738367 kB
VmallocUsed: 0 kB
VmallocChunk: 0 kB
HardwareCorrupted: 0 kB
AnonHugePages: 22528 kB
ShmemHugePages: 0 kB
ShmemPmdMapped: 0 kB
CmaTotal: 0 kB
CmaFree: 0 kB
HugePages_Total: 0
HugePages_Free: 0
HugePages_Rsvd: 0
HugePages_Surp: 0
Hugepagesize: 2048 kB
DirectMap4k: 937976 kB
DirectMap2M: 1159168 kB
zone
sh@tencent_cloud:/ $ cat /proc/zoneinfo
Node 0, zone DMA
per-node stats
nr_inactive_anon 69990 #不活跃的匿名页面数量
nr_active_anon 63512 #活跃的匿名页面数量
nr_inactive_file 66070 #不活跃的文件数量
nr_active_file 106456 #活跃的文件数量
nr_unevictable 0
nr_slab_reclaimable 46500
nr_slab_unreclaimable 18531
nr_isolated_anon 0
nr_isolated_file 0
workingset_refault 9595434
workingset_activate 1613846
workingset_nodereclaim 273918
nr_anon_pages 127743
nr_mapped 32598
nr_file_pages 189232
nr_dirty 125
nr_writeback 0
nr_writeback_temp 0
nr_shmem 3504
nr_shmem_hugepages 0
nr_shmem_pmdmapped 0
nr_anon_transparent_hugepages 11
nr_unstable 0
nr_vmscan_write 611232
nr_vmscan_immediate_reclaim 117183
nr_dirtied 10693130
nr_written 11016332
pages free 2360
min 99
low 123
high 147
spanned 4095
present 3998
managed 3977
protection: (0, 1750, 1750, 1750, 1750)
nr_free_pages 2360
nr_zone_inactive_anon 298
nr_zone_active_anon 141
nr_zone_inactive_file 6
nr_zone_active_file 535
nr_zone_unevictable 0
nr_zone_write_pending 0
nr_mlock 0
nr_page_table_pages 7
nr_kernel_stack 0
nr_bounce 0
nr_zspages 0
nr_free_cma 0
numa_hit 759691
numa_miss 0
numa_foreign 0
numa_interleave 0
numa_local 759691
numa_other 0
pagesets
cpu: 0
count: 0
high: 0
batch: 1
vm stats threshold: 2
node_unreclaimable: 0
start_pfn: 1
Node 0, zone DMA32
pages free 76925
min 11164
low 13955
high 16746
spanned 520190
present 520190
managed 465399
protection: (0, 0, 0, 0, 0)
nr_free_pages 76925
nr_zone_inactive_anon 69692
nr_zone_active_anon 63371
nr_zone_inactive_file 66064
nr_zone_active_file 105921
nr_zone_unevictable 0
nr_zone_write_pending 125
nr_mlock 0
nr_page_table_pages 7667
nr_kernel_stack 6796
nr_bounce 0
nr_zspages 0
nr_free_cma 0
numa_hit 569528359
numa_miss 0
numa_foreign 0
numa_interleave 47596
numa_local 569528359
numa_other 0
pagesets
cpu: 0
count: 109
high: 186
batch: 31
vm stats threshold: 10
node_unreclaimable: 0
start_pfn: 4096
Node 0, zone Normal
pages free 0
min 0
low 0
high 0
spanned 0
present 0
managed 0
protection: (0, 0, 0, 0, 0)
Node 0, zone Movable
pages free 0
min 0
low 0
high 0
spanned 0
present 0
managed 0
protection: (0, 0, 0, 0, 0)
Node 0, zone Device
pages free 0
min 0
low 0
high 0
spanned 0
present 0
managed 0
protection: (0, 0, 0, 0, 0)
buddyinfo
/proc/buddyinfo 是系统中伙伴系统的信息
伙伴系统中 是以 page_block为单位去管理 内存的，page_block的单位也是 2^ORDER,
其中 0 < ORDER < 11.
每一行 是以 type 作为区分的
下面每一列 都是以 page_block size作为区分的
sh@tencent_cloud:/ $ cat /proc/buddyinfo
Node 0, zone DMA 88 70 73 18 12 11 6 2 2 0 0
Node 0, zone DMA32 2453 511 2158 1859 1063 561 75 20 11 0 0
slabinfo
/proc/slabinfo 是系统中 slab 结构的信息
sh@tencent_cloud:/ $ sudo cat /proc/slabinfo
slabinfo - version: 2.1
# name : tunables : slabdata
au_finfo 0 0 192 21 1 : tunables 0 0 0 : slabdata 0 0 0
au_icntnr 0 0 768 10 2 : tunables 0 0 0 : slabdata 0 0 0
…………
vmallocinfo
/proc/vmallocinfo 是系统中伙伴系统的信息
sh@tencent_cloud:/ $ sudo cat /proc/vmallocinfo
0xffffbf3040000000-0xffffbf3040002000 8192 acpi_os_map_iomem+0x17c/0x1b0 phys=0x000000007ffff000 ioremap
0xffffbf3040002000-0xffffbf3040005000 12288 acpi_os_map_iomem+0x17c/0x1b0 phys=0x000000007fffe000 ioremap
0xffffbf3040005000-0xffffbf3040206000 2101248 alloc_large_system_hash+0x19c/0x259 pages=512 vmalloc N0=512
0xffffbf3040206000-0xffffbf3040307000 1052672 alloc_large_system_hash+0x19c/0x259 pages=256 vmalloc N0=256
0xffffbf3040307000-0xffffbf3040310000 36864 alloc_large_system_hash+0x19c/0x259 pages=8 vmalloc N0=8
0xffffbf3040310000-0xffffbf3040319000 36864 alloc_large_system_hash+0x19c/0x259 pages=8 vmalloc N0=8
0xffffbf3040319000-0xffffbf304031b000 8192 bpf_prog_alloc+0x4c/0xc0 pages=1 vmalloc N0=1
0xffffbf304031c000-0xffffbf3040321000 20480 _do_fork+0xdf/0x400 pages=4 vmalloc N0=4
0xffffbf3040321000-0xffffbf3040323000 8192 acpi_os_map_iomem+0x17c/0x1b0 phys=0x00000000fed00000 ioremap
0xffffbf3040324000-0xffffbf3040329000 20480 _do_fork+0xdf/0x400 pages=4 vmalloc N0=4
0xffffbf3040329000-0xffffbf304032b000 8192 memremap+0x122/0x180 phys=0x00000000000fd000 ioremap
pagetypeinfo
/proc/pagetypeinfo 是系统中伙伴系统的信息
不过比 buddy_info更加详细，这里把 page_block 更加细分 为 Unmovable Movable HighAtomic CMA Isolate 这几种类型
sh@tencent_cloud:/ $ sudo cat /proc/pagetypeinfo
Page block order: 9
Pages per block: 512
Free pages count per migrate type at order 0 1 2 3 4 5 6 7 8 9 10
Node 0, zone DMA, type Unmovable 8 12 13 5 9 3 3 1 1 0 0
Node 0, zone DMA, type Movable 75 56 50 10 0 1 0 1 1 0 0
Node 0, zone DMA, type Reclaimable 5 2 10 3 3 7 3 0 0 0 0
Node 0, zone DMA, type HighAtomic 0 0 0 0 0 0 0 0 0 0 0
Node 0, zone DMA, type CMA 0 0 0 0 0 0 0 0 0 0 0
Node 0, zone DMA, type Isolate 0 0 0 0 0 0 0 0 0 0 0
Node 0, zone DMA32, type Unmovable 140 172 139 46 30 17 11 4 2 0 0
Node 0, zone DMA32, type Movable 8325 3763 2401 1616 969 496 39 4 8 0 0
Node 0, zone DMA32, type Reclaimable 1062 357 155 226 57 47 24 12 0 0 0
cpuinfo
/proc/cpuinfo 是系统中伙伴系统 CPU 的详细信息
sh@tencent_cloud:/ $ sudo cat /proc/cpuinfo
processor : 0
vendor_id : GenuineIntel
cpu family : 6
model : 79
model name : Intel(R) Xeon(R) CPU E5-26xx v4
stepping : 1
microcode : 0x1
cpu MHz : 2394.454
cache size : 4096 KB
physical id : 0
siblings : 1
core id : 0
cpu cores : 1
apicid : 0
initial apicid : 0
fpu : yes
fpu_exception : yes
cpuid level : 13
wp : yes
flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush mmx fxsr sse sse2 ss ht syscall nx lm constant_tsc rep_good nopl cpuid tsc_known_freq pni pclmulqdq ssse3 fma cx16 pcid sse4_1 sse4_2 x2apic movbe popcnt tsc_deadline_timer aes xsave avx f16c rdrand hypervisor lahf_lm abm 3dnowprefetch pti bmi1 avx2 bmi2 rdseed adx xsaveopt
bugs : cpu_meltdown spectre_v1 spectre_v2 spec_store_bypass l1tf mds
bogomips : 4788.90
clflush size : 64
cache_alignment : 64
address sizes : 40 bits physical, 48 bits virtual
power management:
可参考: https://www.cnblogs.com/arnoldlu/p/8568330.html
由于 参数太多，一时半会儿 无法全部注释完，还有一部分我也不知道啥意思，后面有空
会 慢慢补充，结合代码分析这些参数具体在代码中使用的什么数据结构