Pessoal,
acabei de colocar um server em produção, daí estou monitorando ele com maior frequência.
Usei o comando dmesg, e ele retornou-me as seguintes mensagens:
swapper: page allocation failure. order:1, mode:0x20
[<c014bfb1>] __alloc_pages+0x2d1/0x2f0
[<c0162818>] cache_alloc_refill+0x2c8/0x4f0
[<c0161e59>] cache_flusharray+0x59/0xd0
[<c0162aac>] __kmalloc+0x6c/0x80
[<c03ac843>] __alloc_skb+0x53/0x110
[<c03e4e95>] tcp_collapse+0x1a5/0x380
[<c03e519c>] tcp_prune_queue+0x12c/0x320
[<c03e5b9c>] tcp_data_queue+0x80c/0xc00
[<c03c8e79>] __nf_conntrack_find+0x19/0x120
[<c03ca4db>] nf_conntrack_in+0x27b/0x5a0
[<c03e7686>] tcp_rcv_established+0x2a6/0x920
[<f8a0a75b>] ipt_do_table+0x21b/0x350 [ip_tables]
[<c03eda33>] tcp_v4_do_rcv+0xc3/0x310
[<c03cddda>] nf_ct_deliver_cached_events+0x8a/0xa0
[<f8a1b25b>] ipv4_confirm+0x2b/0x50 [nf_conntrack_ipv4]
[<c03f008d>] tcp_v4_rcv+0x78d/0x930
[<c03d2aa0>] ip_rcv_finish+0x0/0x280
[<c03d3622>] ip_local_deliver+0x122/0x2c0
[<c03d2d20>] ip_local_deliver_finish+0x0/0x200
[<c03d32bc>] ip_rcv+0x2ac/0x4f0
[<c03d2aa0>] ip_rcv_finish+0x0/0x280
[<c03b0f52>] netif_receive_skb+0x232/0x310
[<c03b2a3b>] process_backlog+0x8b/0x120
[<c03b2c81>] net_rx_action+0xc1/0x210
[<c0125782>] __do_softirq+0x82/0xf0
[<c0125827>] do_softirq+0x37/0x40
[<c0125a65>] irq_exit+0x75/0x80
[<c0105430>] do_IRQ+0x40/0x80
[<c054a540>] unknown_bootoption+0x0/0x250
[<c010f8b5>] smp_apic_timer_interrupt+0x55/0x90
[<c054a540>] unknown_bootoption+0x0/0x250
[<c010346f>] common_interrupt+0x23/0x28
[<c01017b0>] default_idle+0x0/0x40
[<c054a540>] unknown_bootoption+0x0/0x250
[<c01017df>] default_idle+0x2f/0x40
[<c0100dcd>] cpu_idle+0x6d/0x90
[<c054adf8>] start_kernel+0x3d8/0x4a0
[<c054a540>] unknown_bootoption+0x0/0x250
=======================
Mem-info:
DMA per-cpu:
CPU 0: Hot: hi: 0, btch: 1 usd: 0 Cold: hi: 0, btch: 1 usd: 0
CPU 1: Hot: hi: 0, btch: 1 usd: 0 Cold: hi: 0, btch: 1 usd: 0
Normal per-cpu:
CPU 0: Hot: hi: 186, btch: 31 usd: 179 Cold: hi: 62, btch: 15 usd: 53
CPU 1: Hot: hi: 186, btch: 31 usd: 110 Cold: hi: 62, btch: 15 usd: 58
HighMem per-cpu:
CPU 0: Hot: hi: 186, btch: 31 usd: 115 Cold: hi: 62, btch: 15 usd: 8
CPU 1: Hot: hi: 186, btch: 31 usd: 162 Cold: hi: 62, btch: 15 usd: 7
Active:255598 inactive:353568 dirty:66 writeback:0 unstable:0
free:40777 slab:61540 mapped:1226 pagetables:149 bounce:0
DMA free:3524kB min:68kB low:84kB high:100kB active:3496kB inactive:2192kB present:16256kB pages_scanned:0 all_unreclaimable? no
lowmem_reserve[]: 0 873 2778
Normal free:2184kB min:3744kB low:4680kB high:5616kB active:386316kB inactive:240216kB present:894080kB pages_scanned:0 all_unreclaimable? no
lowmem_reserve[]: 0 0 15239
HighMem free:157400kB min:512kB low:2556kB high:4600kB active:632580kB inactive:1171864kB present:1950660kB pages_scanned:0 all_unreclaimable? no
lowmem_reserve[]: 0 0 0
DMA: 82*4kB 0*8kB 0*16kB 0*32kB 0*64kB 1*128kB 0*256kB 0*512kB 1*1024kB 1*2048kB 0*4096kB = 3528kB
Normal: 372*4kB 1*8kB 1*16kB 1*32kB 0*64kB 1*128kB 0*256kB 1*512kB 0*1024kB 0*2048kB 0*4096kB = 2184kB
HighMem: 29520*4kB 3963*8kB 250*16kB 33*32kB 4*64kB 0*128kB 3*256kB 1*512kB 1*1024kB 0*2048kB 0*4096kB = 157400kB
Swap cache: add 703, delete 33, find 30/36, race 0+0
Free swap = 2341232kB
Total swap = 2343912kB
Free swap: 2341232kB
720880 pages of RAM
491504 pages of HIGHMEM
7139 reserved pages
499477 pages shared
670 pages swap cached
66 pages dirty
0 pages writeback
1226 pages mapped
61540 pages slab
149 pages pagetables
Isso pode ser algum problema?