我正在运行一个相对简单的程序，它反复调用mmap（）以获得100MB +内存（并触摸它们的每一页）。问题是该程序总是触发内核中的OOM杀手（基于3.4），即使仍有大量物理页面（总共2G RAM和1.6G +是免费的）。
我确实看到这两行输出似乎表明HighMem中没有很多小的空闲块（但仍有许多大块可用）：
Normal: 1220*4kB 1034*8kB 791*16kB 547*32kB 289*64kB 130*128kB 39*256kB 9*512kB 5*1024kB 3*2048kB 149*4096kB = 714608kB
HighMem: 1*4kB 0*8kB 1*16kB 0*32kB 1*64kB 1*128kB 1*256kB 1*512kB 1*1024kB 2*2048kB 254*4096kB = 1046484kB
但是当系统还说有524288 pages of RAM和440840 free pages（大多数是免费的）时，我无法绕过这个。
以下是详细输出。任何帮助表示赞赏！
test_program invoked oom-killer: gfp_mask=0x0, order=0, oom_adj=-17, oom_score_adj=-1000
[<c0011074>] (unwind_backtrace+0x0/0xe0) from [<c00813f0>] (dump_header.isra.16+0x74/0x18c)
[<c00813f0>] (dump_header.isra.16+0x74/0x18c) from [<c0081674>] (oom_kill_process.part.19.constprop.20+0x44/0x268)
[<c0081674>] (oom_kill_process.part.19.constprop.20+0x44/0x268) from [<c0081d64>] (out_of_memory+0x328/0x3f4)
[<c0081d64>] (out_of_memory+0x328/0x3f4) from [<c0081ef0>] (pagefault_out_of_memory+0xc0/0x154)
[<c0081ef0>] (pagefault_out_of_memory+0xc0/0x154) from [<c00120e0>] (do_page_fault+0x1bc/0x244)
[<c00120e0>] (do_page_fault+0x1bc/0x244) from [<c0008364>] (do_DataAbort+0x34/0x98)
[<c0008364>] (do_DataAbort+0x34/0x98) from [<c000d3f4>] (__dabt_usr+0x34/0x40)
Exception stack(0xed479fb0 to 0xed479ff8)
9fa0: aee1cffc aeec2000 0db4da5f aee1d000
9fc0: 00000000 0001b184 00000040 00000059 00000000 00000000 00000000 be9ccacc
9fe0: 00000064 be9cc9f0 0000b037 0000830c 80000030 ffffffff
Mem-info:
Normal per-cpu:
CPU 0: hi: 186, btch: 31 usd: 157
HighMem per-cpu:
CPU 0: hi: 186, btch: 31 usd: 39
active_anon:37727 inactive_anon:936 isolated_anon:0
active_file:4108 inactive_file:25830 isolated_file:0
unevictable:1 dirty:12 writeback:0 unstable:0
free:440273 slab_reclaimable:1457 slab_unreclaimable:2172
mapped:12414 shmem:944 pagetables:752 bounce:0
Normal free:714608kB min:3512kB low:5052kB high:5932kB active_anon:0kB inactive_anon:0kB active_file:788kB inactive_file:1632kB unevictable:0kB isolated(anon):0kB isolated(file):0kB present:772160kB mlocked:0kB dirty:48kB writeback:0kB mapped:0kB shmem:0kB slab_reclaimable:5828kB slab_unreclaimable:8688kB kernel_stack:2032kB pagetables:3008kB unstable:0kB bounce:0kB writeback_tmp:0kB pages_scanned:0 all_unreclaimable? no
lowmem_reserve[]: 0 10223 10223
HighMem free:1046484kB min:512kB low:3128kB high:4616kB active_anon:150908kB inactive_anon:3744kB active_file:15644kB inactive_file:101688kB unevictable:4kB isolated(anon):0kB isolated(file):0kB present:1308608kB mlocked:4kB dirty:0kB writeback:0kB mapped:49656kB shmem:3776kB slab_reclaimable:0kB slab_unreclaimable:0kB kernel_stack:0kB pagetables:0kB unstable:0kB bounce:0kB writeback_tmp:0kB pages_scanned:0 all_unreclaimable? no
lowmem_reserve[]: 0 0 0
Normal: 1220*4kB 1034*8kB 791*16kB 547*32kB 289*64kB 130*128kB 39*256kB 9*512kB 5*1024kB 3*2048kB 149*4096kB = 714608kB
HighMem: 1*4kB 0*8kB 1*16kB 0*32kB 1*64kB 1*128kB 1*256kB 1*512kB 1*1024kB 2*2048kB 254*4096kB = 1046484kB
30879 total pagecache pages
0 pages in swap cache
Swap cache stats: add 0, delete 0, find 0/1
Free swap = 0kB
Total swap = 0kB
524288 pages of RAM
440840 free pages
9650 reserved pages
3629 slab pages
59279 pages shared
0 pages swap cached