[Asterisk-Users] Very high size-32 usage

[Anthony Rodgers]

Hi there,

Has anyone noticed very high size-32 allocations in Asterisk servers 
with Digium hardware installed? Here is output from /proc/slabinfo:

size-32           23763586 23763586     32  119    1 : tunables  120   
60    0 : slabdata 199694 199694      0

Here is the summary and first few rows from slabtop:

  Active / Total Objects (% used)    : 23850372 / 23890412 (99.8%)
  Active / Total Slabs (% used)      : 204139 / 204139 (100.0%)
  Active / Total Caches (% used)     : 95 / 134 (70.9%)
  Active / Total Size (% used)       : 756630.62K / 760089.77K (99.5%)
  Minimum / Average / Maximum Object : 0.01K / 0.03K / 128.00K

   OBJS ACTIVE  USE OBJ SIZE  SLABS OBJ/SLAB CACHE SIZE NAME
23764300 23764241 -80%    0.03K 199700      119    798800K size-32
   5085   5085 100%    0.68K   1017        5      4068K ext3_inode_cache
  51075  20557  40%    0.05K    681       75      2724K buffer_head
   8008   3666  45%    0.27K    572       14      2288K radix_tree_node
   9936   9863  99%    0.16K    432       23      1728K dentry_cache
   8463   8463 100%    0.12K    273       31      1092K size-128
    256    256 100%    3.00K    128        2      1024K biovec-(256)

As you can see, almost 800MB of memory on this box is taken up with 
size-32 pages.

This particular server is a single CPU box running Asterisk 1.2.5 and 
Zaptel 1.2.4 on RHEL4 and is a low-use, test box. Our two production 
boxes are dual 3.4GHz Xeons running Asterisk 1.2.1 and Zaptel 1.2.1 on 
RHEL4 SMP and exhibit the same issue (it was running into oom-killer 
problems with low LOWMEM on one of them that triggered all of this).

Interestingly, we have an identical server to our test server that does 
not have Asterisk or Zaptel installed, and it does not display this 
issue.

Has anyone else encountered this issue? What does your slabtop look 
like?

Any thoughts or ideas would be appreciated.

Regards,
-- 
Anthony Rodgers
Business Systems Analyst
District of North Vancouver
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