kernel freeze

kernel freeze

[Joël Krähemann]

https://sourceforge.net/p/ags/blog/2014/03/warning-freezed-gnulinux/

kernel freeze

[kcn]

  After I reported a kernel freeze in this mail list("2.4.18 freeze on
4G memory."),
I try 2.4.19 & 2.4.19+rmap14a patch, all of those have been frozen.
I try to enable kernel profiling to detect what is the problem and found

the function _text_lock_vmscan make the cpu busy. Any comment?
The result below:
  Normal state:
# uptime
12:20pm  up  2:00,  6 users,  load average: 8.18, 10.13, 8.28
# vmstat 2 2
   procs                      memory    swap          io     system
cpu
 r  b  w   swpd   free   buff  cache  si  so    bi    bo   in    cs  us
sy  id
 1  0  4      0 182988 408272 1919636   0   0    89   164  853   499  11
9  79
 0  1  0      0 184288 408516 1919840   0   0   332    12 4869  2587  20
30  50
# readprofile | sort -g
   ...
    36 _text_lock_vmscan                          0.2727
   ...
  4666 _text_lock_read_write                     95.2245
  5027 _text_lock_namei                           2.8465
  5113 ip_packet_match                           13.8940
  6124 _text_lock_inode                          12.6529
  6342 prune_icache                              11.3250
  7549 shrink_cache                               8.1347
 10010 __constant_memcpy                         36.8015
 11099 _text_lock_swap                          194.7193
1242957 default_idle                             15536.9625
1414706 total                                      1.0008
 after freeze:
#uptime
12:44pm  up  2:25,  6 users,  load average: 292.05, 528.62, 117.95
#vmstat 2 2
   procs                      memory    swap          io     system
cpu
 r  b  w   swpd   free   buff  cache  si  so    bi    bo   in    cs  us
sy  id
 9 207  4      0 565776 337108 1948476   0   0    77   144  751   433
10  22  68
 3 239  1      0 548152 337312 1949624   0   0   718  3666 2256  2789
34  38  27
# readprofile | sort -g
  ...
21999 _text_lock_swap                          385.9474
 84239 prune_icache                             150.4268
101555 _text_lock_inode                         209.8244
122285 shrink_cache                             131.7726
173019 _text_lock_vmscan                        1310.7500
1311668 default_idle                             16395.8500
1992753 total                                      1.4098

Re: kernel freeze

[Martin J. Bligh]

>   After I reported a kernel freeze in this mail list("2.4.18 freeze on
> 4G memory."),
> I try 2.4.19 & 2.4.19+rmap14a patch, all of those have been frozen.
> I try to enable kernel profiling to detect what is the problem and found
> the function _text_lock_vmscan make the cpu busy. Any comment?

I'll lay you a large bet that lowmem is full of garbage.
Probably buffer_heads, inodes or PTEs. Output of /proc/meminfo 
and /proc/slabinfo as you approach oblivion would be useful.
As would a description of the workload that triggers it.

M.

Re: kernel freeze

[kcn]

> I'll lay you a large bet that lowmem is full of garbage.
> Probably buffer_heads, inodes or PTEs. Output of /proc/meminfo 
> and /proc/slabinfo as you approach oblivion would be useful.
> As would a description of the workload that triggers it.
>
> M.
  I think it's the reason. But I have to decreased memory from 4G to 2G
because of the complain from my customers, so I can't give you the
/proc/meminfo or /proc/slabinfo now. :(
  Why the linux-vm can't manage lowmem correctly? I have seen some
articles talking about the LRU pre zone patch, but why 2.4.19+rmap14a
patch also has this problem?

Re: kernel freeze

[Martin J. Bligh]

>> I'll lay you a large bet that lowmem is full of garbage.
>> Probably buffer_heads, inodes or PTEs. Output of /proc/meminfo 
>> and /proc/slabinfo as you approach oblivion would be useful.
>> As would a description of the workload that triggers it.
>> 
>> M.
>   I think it's the reason. But I have to decreased memory from 4G to 2G
> because of the complain from my customers, so I can't give you the
> /proc/meminfo or /proc/slabinfo now. :(

The patches don't seem to have wended their way back to mainline
yet, probably because people have been concentrating on 2.5 recently.
I think Andrea's -aa kernel has fixes for most, if not all of these
problems.

>   Why the linux-vm can't manage lowmem correctly? I have seen some
> articles talking about the LRU pre zone patch, but why 2.4.19+rmap14a
> patch also has this problem?

rmap won't help you in this instance, as the stuff you're filling
ZONE_NORMAL with is unswappable. In fact, it may make it worse,
due the overhead of pte_chains ... but this will probably only
hurt you if you have many large tasks sharing memory.

Changing PAGE_OFFSET from 3Gb to 2Gb may be a better workaround than
decreasing from 4Gb to 2Gb of RAM, if you don't have any huge single
process.

M.

Kernel Freeze

[Luca Adesso]

I have installed Linux (Slackware 8.0) on a Abit Pt5 with last bios.
The kernel with that distribution is 2.4.5 and I'm trying to compile kernel 
2.4.9 downloaded from kernel.org
I already compiled that kernel on my notebook and it works fine, but 
everytime I reboot my p133 (the one with the abit) it freeze.
It load the kernel and uncompress it and then... nothing!

I tried to make a light kernel and a big kernel but... nothing.

What can I do?

2TN
"Si sedette e fece finta di essere il Conte Zero"
Count -Zero.nnenne
ICQ:1685183

Re: Kernel Freeze

[Nicholas Knight]

On Thursday 27 September 2001 03:28 pm, Luca Adesso wrote:
> I have installed Linux (Slackware 8.0) on a Abit Pt5 with last bios.
> The kernel with that distribution is 2.4.5 and I'm trying to compile
> kernel 2.4.9 downloaded from kernel.org
> I already compiled that kernel on my notebook and it works fine, but
> everytime I reboot my p133 (the one with the abit) it freeze.
> It load the kernel and uncompress it and then... nothing!
>
> I tried to make a light kernel and a big kernel but... nothing.
>
> What can I do?
>

Check to ensure you're not compiling for a 686 or other chip 
family/revision above the capabilities of your processor (Processor 
Type and Features - XXX Processor Family where XXX is whatever is 
currently selected, select that and hit enter)