oom-killer works,but the memory cannot be freed

oom-killer works,but the memory cannot be freed

[Bill Xie]

My harware is a mips-achitecture hand-hold device, runs 2.6.24.3 and qt.
when an application program  opened a 3.2M pdf file, the memory was
consuming continually, finally the "oom-killer" things happened, the
applicaton was killed,
 but the memory occupied by the application still can not be freed. Is
there some methods
to do with this situation?

Re: oom-killer works,but the memory cannot be freed

[Chungki woo]

Hi~ bill
There is no enough information about your problem.
Can you show me some logs like oom message and /proc/meminfo after oom?

2009/8/26 Bill Xie <bill790@gmail.com>:
> My harware is a mips-achitecture hand-hold device, runs 2.6.24.3 and qt.
> when an application program  opened a 3.2M pdf file, the memory was
> consuming continually, finally the "oom-killer" things happened, the
> applicaton was killed,
>  but the memory occupied by the application still can not be freed. Is
> there some methods

I want to know why you think like this.

> to do with this situation?
> --
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Thanks.

Re: oom-killer works,but the memory cannot be freed

[Bill Xie]

[-- Attachment #1: Type: text/plain, Size: 1007 bytes --]

and the oom killer message attached.  It seems when at this situation,

echo 3 > /proc/sys/vm/drop_caches , cannot release the memory occupied
by the application.



On Fri, Aug 28, 2009 at 2:49 PM, Bill Xie<bill790@gmail.com> wrote:
> hi, woo
>
>  thanks for your replay.
>
> cat /proc/meminfo
> MemTotal:        60288 kB
> MemFree:          5100 kB
> Buffers:             8 kB
> Cached:          25600 kB
> SwapCached:          0 kB
> Active:          21836 kB
> Inactive:        15448 kB
> SwapTotal:           0 kB
> SwapFree:            0 kB
> Dirty:               0 kB
> Writeback:           0 kB
> AnonPages:       11740 kB
> Mapped:           1668 kB
> Slab:             2532 kB
> SReclaimable:      308 kB
> SUnreclaim:       2224 kB
> PageTables:        164 kB
> NFS_Unstable:        0 kB
> Bounce:              0 kB
> CommitLimit:     30144 kB
> Committed_AS:    15656 kB
> VmallocTotal:  1048404 kB
> VmallocUsed:      9700 kB
> VmallocChunk:  1038704 kB
>

[-- Attachment #2: oom-killer-630-1 --]
[-- Type: application/octet-stream, Size: 4717 bytes --]

hotplug invoked oom-killer: gfp_mask=0x1200d2, order=0, oomkilladj=0
Call Trace:
[<800207dc>] dump_stack+0x8/0x34
[<8007cb30>] oom_kill_process+0x138/0x148
[<8007d1f0>] out_of_memory+0x1f0/0x340
[<800806a4>] __alloc_pages+0x2a4/0x3d0
[<8008ebd8>] do_wp_page+0x12c/0x8ec
[<800913a0>] handle_mm_fault+0x718/0x938
[<80024a1c>] do_page_fault+0x12c/0x3b0
[<800196e4>] ret_from_exception+0x0/0x10

Mem-info:
Normal per-cpu:
CPU    0: Hot: hi:   18, btch:   3 usd:   3   Cold: hi:    6, btch:   1 usd:   0
Active:7767 inactive:2992 dirty:0 writeback:0 unstable:0
 free:252 slab:676 mapped:95 pagetables:99 bounce:0
Normal free:1008kB min:1016kB low:1268kB high:1524kB active:31068kB inactive:11968kB press
lowmem_reserve[]: 0 0
Normal: 0*4kB 2*8kB 2*16kB 0*32kB 1*64kB 1*128kB 1*256kB 1*512kB 0*1024kB 0*2048kB 0*4096B
Swap cache: add 0, delete 0, find 0/0, race 0+0
Free swap  = 0kB
Total swap = 0kB
Free swap:            0kB
16384 pages of RAM
0 pages of HIGHMEM
2467 reserved pages
2376 pages shared
0 pages swap cached
Out of memory (oom_kill_allocating_task): kill process 511 (hotplug) score 0 or a child
Killed process 511 (hotplug)
qpe invoked oom-killer: gfp_mask=0x1201d2, order=0, oomkilladj=0
Call Trace:
[<800207dc>] dump_stack+0x8/0x34
[<8007cb30>] oom_kill_process+0x138/0x148
[<8007d1f0>] out_of_memory+0x1f0/0x340
[<800806a4>] __alloc_pages+0x2a4/0x3d0
[<8007b5fc>] filemap_fault+0x130/0x64c
[<8008e540>] __do_fault+0x80/0x5ec
[<80090dd0>] handle_mm_fault+0x148/0x938
[<80024a1c>] do_page_fault+0x12c/0x3b0
[<800196e4>] ret_from_exception+0x0/0x10

Mem-info:
Normal per-cpu:
CPU    0: Hot: hi:   18, btch:   3 usd:   4   Cold: hi:    6, btch:   1 usd:   5
Active:7436 inactive:3210 dirty:0 writeback:0 unstable:0
 free:316 slab:681 mapped:0 pagetables:104 bounce:0
Normal free:1264kB min:1016kB low:1268kB high:1524kB active:29744kB inactive:12840kB press
lowmem_reserve[]: 0 0
Normal: 72*4kB 0*8kB 1*16kB 0*32kB 1*64kB 1*128kB 1*256kB 1*512kB 0*1024kB 0*2048kB 0*409B
Swap cache: add 0, delete 0, find 0/0, race 0+0
Free swap  = 0kB
Total swap = 0kB
Free swap:            0kB
16384 pages of RAM
0 pages of HIGHMEM
2467 reserved pages
2246 pages shared
0 pages swap cached
Out of memory (oom_kill_allocating_task): kill process 505 (qpe) score 0 or a child
Killed process 505 (qpe)
udevd invoked oom-killer: gfp_mask=0x1201d2, order=0, oomkilladj=-17
Call Trace:
[<800207dc>] dump_stack+0x8/0x34
[<8007cb30>] oom_kill_process+0x138/0x148
[<8007d1f0>] out_of_memory+0x1f0/0x340
[<800806a4>] __alloc_pages+0x2a4/0x3d0
[<8007b5fc>] filemap_fault+0x130/0x64c
[<8008e540>] __do_fault+0x80/0x5ec
[<80090dd0>] handle_mm_fault+0x148/0x938
[<80024a1c>] do_page_fault+0x12c/0x3b0
[<800196e4>] ret_from_exception+0x0/0x10

Mem-info:
Normal per-cpu:
CPU    0: Hot: hi:   18, btch:   3 usd:  15   Cold: hi:    6, btch:   1 usd:   0
Active:5631 inactive:5104 dirty:0 writeback:0 unstable:0
 free:253 slab:681 mapped:62 pagetables:104 bounce:0
Normal free:1012kB min:1016kB low:1268kB high:1524kB active:22524kB inactive:20416kB press
lowmem_reserve[]: 0 0
Normal: 9*4kB 0*8kB 1*16kB 0*32kB 1*64kB 1*128kB 1*256kB 1*512kB 0*1024kB 0*2048kB 0*4096B
Swap cache: add 0, delete 0, find 0/0, race 0+0
Free swap  = 0kB
Total swap = 0kB
Free swap:            0kB
16384 pages of RAM
0 pages of HIGHMEM
2467 reserved pages
1501 pages shared
0 pages swap cached
Out of memory (oom_kill_allocating_task): kill process 509 (udevd) score 0 or a child
FAT: unable to read inode block for updating (i_pos 62482)
FAT: unable to read inode block for updating (i_pos 62482)
office invoked oom-killer: gfp_mask=0x1201d2, order=0, oomkilladj=0
Call Trace:
[<800207dc>] dump_stack+0x8/0x34
[<8007cb30>] oom_kill_process+0x138/0x148
[<8007d1f0>] out_of_memory+0x1f0/0x340
[<800806a4>] __alloc_pages+0x2a4/0x3d0
[<8007b5fc>] filemap_fault+0x130/0x64c
[<8008e540>] __do_fault+0x80/0x5ec
[<80090dd0>] handle_mm_fault+0x148/0x938
[<80024a1c>] do_page_fault+0x12c/0x3b0
[<800196e4>] ret_from_exception+0x0/0x10

Mem-info:
Normal per-cpu:
CPU    0: Hot: hi:   18, btch:   3 usd:   4   Cold: hi:    6, btch:   1 usd:   5
Active:8059 inactive:2560 dirty:0 writeback:0 unstable:0
 free:321 slab:677 mapped:0 pagetables:98 bounce:0
Normal free:1284kB min:1016kB low:1268kB high:1524kB active:32236kB inactive:10240kB press
lowmem_reserve[]: 0 0
Normal: 77*4kB 0*8kB 1*16kB 0*32kB 1*64kB 1*128kB 1*256kB 1*512kB 0*1024kB 0*2048kB 0*409B
Swap cache: add 0, delete 0, find 0/0, race 0+0
Free swap  = 0kB
Total swap = 0kB
Free swap:            0kB
16384 pages of RAM
0 pages of HIGHMEM
2467 reserved pages
235 pages shared
0 pages swap cached
Out of memory (oom_kill_allocating_task): kill process 499 (office) score 0 or a child
Killed process 499 (office)

Re: oom-killer works,but the memory cannot be freed

[David Rientjes]

On Fri, 28 Aug 2009, Bill Xie wrote:

> and the oom killer message attached.  It seems when at this situation,
> 
> echo 3 > /proc/sys/vm/drop_caches , cannot release the memory occupied
> by the application.
> 
> hotplug invoked oom-killer: gfp_mask=0x1200d2, order=0, oomkilladj=0
> Call Trace:
> [<800207dc>] dump_stack+0x8/0x34
> [<8007cb30>] oom_kill_process+0x138/0x148
> [<8007d1f0>] out_of_memory+0x1f0/0x340
> [<800806a4>] __alloc_pages+0x2a4/0x3d0
> [<8008ebd8>] do_wp_page+0x12c/0x8ec
> [<800913a0>] handle_mm_fault+0x718/0x938
> [<80024a1c>] do_page_fault+0x12c/0x3b0
> [<800196e4>] ret_from_exception+0x0/0x10
> 
> Mem-info:
> Normal per-cpu:
> CPU    0: Hot: hi:   18, btch:   3 usd:   3   Cold: hi:    6, btch:   1 usd:   0
> Active:7767 inactive:2992 dirty:0 writeback:0 unstable:0
>  free:252 slab:676 mapped:95 pagetables:99 bounce:0
> Normal free:1008kB min:1016kB low:1268kB high:1524kB active:31068kB inactive:11968kB press
> lowmem_reserve[]: 0 0
> Normal: 0*4kB 2*8kB 2*16kB 0*32kB 1*64kB 1*128kB 1*256kB 1*512kB 0*1024kB 0*2048kB 0*4096B
> Swap cache: add 0, delete 0, find 0/0, race 0+0
> Free swap  = 0kB
> Total swap = 0kB
> Free swap:            0kB
> 16384 pages of RAM
> 0 pages of HIGHMEM
> 2467 reserved pages
> 2376 pages shared
> 0 pages swap cached
> Out of memory (oom_kill_allocating_task): kill process 511 (hotplug) score 0 or a child

The key part of these diagnostic messages is the last line, where it says 
you're using oom_kill_allocating_task.  Notice the badness score of the 
task chosen for oom kill, hotplug, is 0, meaning that it's not going to 
lead to any future memory freeing.

We should probably check if badness(current) is 0 before killing it when 
oom_kill_allocating_task is enabled to ensure something worthwhile is 
actually killed.

In the meantime, try

	echo 0 > /proc/sys/vm/oom_kill_allocating_task

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