Out of memory: kill process 7559 (rsync) score 635 or a child
Killed process 7559 (rsync)

I was surprised to see this in my dmesg when my rsync backup suddenly stalled/stopped.

This system has 3 gigs of RAM and lots of free memory so I don't understand what is happening.

rsync invoked oom-killer: gfp_mask=0x200d2, order=0, oomkilladj=0
Pid: 7600, comm: rsync Not tainted 2.6.24.2 #83
 [<c014990e>] oom_kill_process+0x10e/0x120
 [<c0149aab>] out_of_memory+0xbb/0x110
 [<c014b3cb>] __alloc_pages+0x2bb/0x360
 [<c0147f8b>] __grab_cache_page+0x7b/0xc0
 [<c0185739>] simple_commit_write+0x59/0x70
 [<c0185694>] simple_write_begin+0x34/0x80
 [<c01483b4>] generic_perform_write+0xb4/0x1a0
 [<c0148524>] generic_file_buffered_write+0x84/0x150
 [<c0148866>] __generic_file_aio_write_nolock+0x276/0x570
 [<c06ef7a0>] do_sock_read+0x90/0xa0
 [<c06ef828>] sock_aio_read+0x78/0x90
 [<c0148ca4>] generic_file_aio_write+0x64/0xe0
 [<c016964d>] do_sync_write+0xbd/0x110
 [<c0131aa0>] autoremove_wake_function+0x0/0x50
 [<c0169731>] vfs_write+0x91/0x150
 [<c01698a1>] sys_write+0x41/0x70
 [<c01031de>] syscall_call+0x7/0xb
 =======================
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
CPU    2: Hot: hi:    0, btch:   1 usd:   0   Cold: hi:    0, btch:   1 usd:   0
CPU    3: 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:  63   Cold: hi:   62, btch:  15 usd:  21
CPU    1: Hot: hi:  186, btch:  31 usd:  59   Cold: hi:   62, btch:  15 usd:   2
CPU    2: Hot: hi:  186, btch:  31 usd:  37   Cold: hi:   62, btch:  15 usd:   9
CPU    3: Hot: hi:  186, btch:  31 usd:  37   Cold: hi:   62, btch:  15 usd:   0
HighMem per-cpu:
CPU    0: Hot: hi:  186, btch:  31 usd:  63   Cold: hi:   62, btch:  15 usd:   8
CPU    1: Hot: hi:  186, btch:  31 usd:  11   Cold: hi:   62, btch:  15 usd:   0
CPU    2: Hot: hi:  186, btch:  31 usd:  55   Cold: hi:   62, btch:  15 usd:   0
CPU    3: Hot: hi:  186, btch:  31 usd: 186   Cold: hi:   62, btch:  15 usd:  12
Active:337341 inactive:332842 dirty:0 writeback:0 unstable:0
 free:28044 slab:6711 mapped:48 pagetables:104 bounce:0
DMA free:6416kB min:68kB low:84kB high:100kB active:0kB inactive:0kB present:16256kB pages_scanned:0 all_unreclaimable? yes
lowmem_reserve[]: 0 873 4048 4048
Normal free:105332kB min:3744kB low:4680kB high:5616kB active:361796kB inactive:361852kB present:894080kB pages_scanned:1084885 all_unreclaimable? yes
lowmem_reserve[]: 0 0 25400 25400
HighMem free:428kB min:512kB low:3916kB high:7324kB active:987568kB inactive:969516kB present:3251200kB pages_scanned:2938373 all_unreclaimable? yes
lowmem_reserve[]: 0 0 0 0
DMA: 6*4kB 7*8kB 8*16kB 8*32kB 7*64kB 5*128kB 3*256kB 2*512kB 3*1024kB 0*2048kB 0*4096kB = 6416kB
Normal: 14*4kB 18*8kB 7*16kB 2*32kB 1*64kB 2*128kB 2*256kB 1*512kB 3*1024kB 3*2048kB 23*4096kB = 105144kB
HighMem: 0*4kB 1*8kB 1*16kB 1*32kB 1*64kB 0*128kB 1*256kB 0*512kB 0*1024kB 0*2048kB 0*4096kB = 376kB
Swap cache: add 0, delete 0, find 0/0, race 0+0
Free swap  = 0kB
Total swap = 0kB
Free swap:            0kB
1048576 pages of RAM
819200 pages of HIGHMEM
339234 reserved pages
10551 pages shared
0 pages swap cached
0 pages dirty
0 pages writeback
48 pages mapped
6711 pages slab
104 pages pagetables
Out of memory: kill process 7559 (rsync) score 955 or a child
Killed process 7600 (rsync)
rsync invoked oom-killer: gfp_mask=0x1280d2, order=0, oomkilladj=0
Pid: 7559, comm: rsync Not tainted 2.6.24.2 #83
 [<c014990e>] oom_kill_process+0x10e/0x120
 [<c0149aab>] out_of_memory+0xbb/0x110
 [<c014b3cb>] __alloc_pages+0x2bb/0x360
 [<c01561b7>] __do_fault+0x147/0x360
 [<c0155f9d>] do_anonymous_page+0x3d/0x110
 [<c015669f>] handle_mm_fault+0x10f/0x2c0
 [<c0113dea>] do_page_fault+0x12a/0x630
 [<c0169572>] vfs_read+0x132/0x150
 [<c0113cc0>] do_page_fault+0x0/0x630
 [<c075ca8a>] error_code+0x72/0x78
 =======================
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
CPU    2: Hot: hi:    0, btch:   1 usd:   0   Cold: hi:    0, btch:   1 usd:   0
CPU    3: 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:  63   Cold: hi:   62, btch:  15 usd:  21
CPU    1: Hot: hi:  186, btch:  31 usd: 114   Cold: hi:   62, btch:  15 usd:   2
CPU    2: Hot: hi:  186, btch:  31 usd:  28   Cold: hi:   62, btch:  15 usd:   9
CPU    3: Hot: hi:  186, btch:  31 usd:  37   Cold: hi:   62, btch:  15 usd:   0
HighMem per-cpu:
CPU    0: Hot: hi:  186, btch:  31 usd:  63   Cold: hi:   62, btch:  15 usd:   8
CPU    1: Hot: hi:  186, btch:  31 usd:  11   Cold: hi:   62, btch:  15 usd:   0
CPU    2: Hot: hi:  186, btch:  31 usd: 138   Cold: hi:   62, btch:  15 usd:   0
CPU    3: Hot: hi:  186, btch:  31 usd: 186   Cold: hi:   62, btch:  15 usd:  12
Active:337376 inactive:332787 dirty:0 writeback:0 unstable:0
 free:28044 slab:6711 mapped:48 pagetables:104 bounce:0
DMA free:6416kB min:68kB low:84kB high:100kB active:0kB inactive:0kB present:16256kB pages_scanned:0 all_unreclaimable? yes
lowmem_reserve[]: 0 873 4048 4048
Normal free:105332kB min:3744kB low:4680kB high:5616kB active:362104kB inactive:361596kB present:894080kB pages_scanned:1085435 all_unreclaimable? yes
lowmem_reserve[]: 0 0 25400 25400
HighMem free:428kB min:512kB low:3916kB high:7324kB active:987400kB inactive:969552kB present:3251200kB pages_scanned:2939498 all_unreclaimable? yes
lowmem_reserve[]: 0 0 0 0
DMA: 6*4kB 7*8kB 8*16kB 8*32kB 7*64kB 5*128kB 3*256kB 2*512kB 3*1024kB 0*2048kB 0*4096kB = 6416kB
Normal: 14*4kB 18*8kB 7*16kB 2*32kB 1*64kB 2*128kB 2*256kB 1*512kB 3*1024kB 3*2048kB 23*4096kB = 105144kB
HighMem: 0*4kB 1*8kB 1*16kB 1*32kB 1*64kB 0*128kB 1*256kB 0*512kB 0*1024kB 0*2048kB 0*4096kB = 376kB
Swap cache: add 0, delete 0, find 0/0, race 0+0
Free swap  = 0kB
Total swap = 0kB
Free swap:            0kB
1048576 pages of RAM
819200 pages of HIGHMEM
339234 reserved pages
903 pages shared
0 pages swap cached
0 pages dirty
0 pages writeback
48 pages mapped
6711 pages slab
104 pages pagetables
Out of memory: kill process 7559 (rsync) score 635 or a child
Killed process 7559 (rsync)