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fly6

事情是这样的：
有调用ifconfig时出错，从message中拿到的日志为：
Nov 15 20:27:54 asm kernel: ifconfig: page allocation failure: order:9, mode:0x8020
Nov 15 20:27:54 asm kernel: Pid: 23014, comm: ifconfig Tainted: P           O 3.2.6 #3
Nov 15 20:27:54 asm kernel: Call Trace:
Nov 15 20:27:54 asm kernel: [<ffffffff8110e0f3>] warn_alloc_failed+0xf3/0x160
Nov 15 20:27:54 asm kernel: [<ffffffff8112b136>] ? do_anonymous_page+0x116/0x350
Nov 15 20:27:54 asm kernel: [<ffffffff811108c1>] __alloc_pages_slowpath+0x421/0x6d0
Nov 15 20:27:54 asm kernel: [<ffffffff81110d14>] __alloc_pages_nodemask+0x1a4/0x1f0
Nov 15 20:27:54 asm kernel: [<ffffffff8114a0da>] alloc_pages_current+0xaa/0x110
Nov 15 20:27:54 asm kernel: [<ffffffff8110ddde>] __get_free_pages+0xe/0x50
Nov 15 20:27:54 asm kernel: [<ffffffff8144f68a>] nl_pid_hash_rehash+0x8a/0x1a0
Nov 15 20:27:54 asm kernel: [<ffffffff8144f8cc>] netlink_insert+0x12c/0x160
Nov 15 20:27:54 asm kernel: [<ffffffff8144f9d3>] netlink_autobind+0xd3/0x100
Nov 15 20:27:54 asm kernel: [<ffffffff8144fe6e>] netlink_bind+0x7e/0x1e0
Nov 15 20:27:54 asm kernel: [<ffffffff81410190>] sys_bind+0xe0/0x100
Nov 15 20:27:54 asm kernel: [<ffffffff811652fd>] ? fd_install+0x3d/0x70
Nov 15 20:27:54 asm kernel: [<ffffffff8140fd9a>] ? sock_map_fd+0x2a/0x40
Nov 15 20:27:54 asm kernel: [<ffffffff814137d1>] ? sys_socket+0x51/0x80
Nov 15 20:27:54 asm kernel: [<ffffffff8150c002>] system_call_fastpath+0x16/0x1b
Nov 15 20:27:54 asm kernel: Mem-Info:
Nov 15 20:27:54 asm kernel: Node 0 DMA per-cpu:
Nov 15 20:27:54 asm kernel: CPU    0: hi:    0, btch:   1 usd:   0
Nov 15 20:27:54 asm kernel: CPU    1: hi:    0, btch:   1 usd:   0
Nov 15 20:27:54 asm kernel: Node 0 DMA32 per-cpu:
Nov 15 20:27:54 asm kernel: CPU    0: hi:  186, btch:  31 usd:  91
Nov 15 20:27:54 asm kernel: CPU    1: hi:  186, btch:  31 usd: 181
Nov 15 20:27:54 asm kernel: Node 0 Normal per-cpu:
Nov 15 20:27:54 asm kernel: CPU    0: hi:  186, btch:  31 usd:  71
Nov 15 20:27:54 asm kernel: CPU    1: hi:  186, btch:  31 usd: 175
Nov 15 20:27:54 asm kernel: active_anon:189379 inactive_anon:883 isolated_anon:0
Nov 15 20:27:54 asm kernel: active_file:33602 inactive_file:33603 isolated_file:8
Nov 15 20:27:54 asm kernel: unevictable:0 dirty:962 writeback:57 unstable:0
Nov 15 20:27:54 asm kernel: free:492056 slab_reclaimable:94342 slab_unreclaimable:126946
Nov 15 20:27:54 asm kernel: mapped:2233 shmem:2091 pagetables:3317 bounce:0
Nov 15 20:27:54 asm kernel: Node 0 DMA free:15912kB min:256kB low:320kB high:384kB active_anon:0kB inactive_anon:0kB active_file:0kB inactive_file:0kB unevictable:0kB isolated(anon):0kB isolated(file):0kB present:15688kB mlocked:0kB dirty:0kB writeback:0kB mapped:0kB shmem:0kB slab_reclaimable:0kB slab_unreclaimable:0kB kernel_stack:0kB pagetables:0kB unstable:0kB bounce:0kB writeback_tmp:0kB pages_scanned:0 all_unreclaimable? yes
Nov 15 20:27:54 asm kernel: lowmem_reserve[]: 0 2964 3974 3974
Nov 15 20:27:54 asm kernel: Node 0 DMA32 free:1822820kB min:50216kB low:62768kB high:75324kB active_anon:530448kB inactive_anon:0kB active_file:58992kB inactive_file:59048kB unevictable:0kB isolated(anon):0kB isolated(file):0kB present:3035936kB mlocked:0kB dirty:3716kB writeback:28kB mapped:20kB shmem:4808kB slab_reclaimable:272880kB slab_unreclaimable:249640kB kernel_stack:328kB pagetables:5480kB unstable:0kB bounce:0kB writeback_tmp:0kB pages_scanned:36 all_unreclaimable? no
Nov 15 20:27:54 asm kernel: lowmem_reserve[]: 0 0 1010 1010
Nov 15 20:27:54 asm kernel: Node 0 Normal free:129492kB min:17104kB low:21380kB high:25656kB active_anon:227068kB inactive_anon:3532kB active_file:75416kB inactive_file:75364kB unevictable:0kB isolated(anon):0kB isolated(file):32kB present:1034240kB mlocked:0kB dirty:132kB writeback:200kB mapped:8912kB shmem:3556kB slab_reclaimable:104488kB slab_unreclaimable:258144kB kernel_stack:936kB pagetables:7788kB unstable:0kB bounce:0kB writeback_tmp:0kB pages_scanned:40 all_unreclaimable? no
Nov 15 20:27:54 asm kernel: lowmem_reserve[]: 0 0 0 0
Nov 15 20:27:54 asm kernel: Node 0 DMA: 0*4kB 1*8kB 0*16kB 1*32kB 2*64kB 1*128kB 1*256kB 0*512kB 1*1024kB 1*2048kB 3*4096kB = 15912kB
Nov 15 20:27:54 asm kernel: Node 0 DMA32: 14755*4kB 3900*8kB 5510*16kB 4757*32kB 3448*64kB 2278*128kB 1472*256kB 716*512kB 229*1024kB 1*2048kB 0*4096kB = 1822828kB
Nov 15 20:27:54 asm kernel: Node 0 Normal: 23037*4kB 4090*8kB 159*16kB 1*32kB 0*64kB 0*128kB 0*256kB 0*512kB 0*1024kB 1*2048kB 0*4096kB = 129492kB
Nov 15 20:27:54 asm kernel: 69281 total pagecache pages
Nov 15 20:27:54 asm kernel: 0 pages in swap cache
Nov 15 20:27:54 asm kernel: Swap cache stats: add 0, delete 0, find 0/0
Nov 15 20:27:54 asm kernel: Free swap  = 0kB
Nov 15 20:27:54 asm kernel: Total swap = 0kB
Nov 15 20:27:54 asm kernel: 1048560 pages RAM
Nov 15 20:27:54 asm kernel: 43170 pages reserved
Nov 15 20:27:54 asm kernel: 88264 pages shared
Nov 15 20:27:54 asm kernel: 447919 pages non-shared

这段日志是显示内存差不多已经消耗得差不多了，但在用户层使用top命令却显示
Mem: 2090332K used, 1931228K free, 0K shrd, 223176K buff, 95988K cached
CPU: 70.0% usr 30.0% sys  0.0% nic  0.0% idle  0.0% io  0.0% irq  0.0% sirq
Load average: 0.03 0.07 0.06 2/150 17813
这里为什么差别特么大，请各位知无不言，言无不尽

crspo

order 9，内存可能已经高度碎片化了

humjb_1983

fly6 发表于 2013-11-19 13:46
事情是这样的：
有调用ifconfig时出错，从message中拿到的日志为：
Nov 15 20:27:54 asm kernel: ifconfi ...

主要是因为低端内存中，没有连续的内存页可用了，需要分配order为9的页，但实际没有这么大的连续页了
Nov 15 20:27:54 asm kernel: Node 0 Normal: 23037*4kB 4090*8kB 159*16kB 1*32kB 0*64kB 0*128kB 0*256kB 0*512kB 0*1024kB 1*2048kB 0*4096kB = 129492kB

top中显示的free内存主要在DMA32管理区中，这个配得有点大了。

fly6

感谢楼上两位的回复，是碎片化的很严重