openstack team mailing list archive

[Rick Jones <rick.jones2@xxxxxx>]

On 07/12/2012 06:36 AM, Kuo Hugo wrote:
> Hi all
>
> I found that the arp_cache in slabinfo on objec-server is growing up 
> followed with uploaded object numbers.
>
> Does any code using it ?

The code which maps from IP to Ethernet addresses does.  That mapping is 
what enables sending IP datagrams to their next-hop destination (which 
may be the final hop, depending) on an Ethernet network.

> 2352000 1329606  56%    0.06K  36750       64 147000K kmalloc-64
> 1566617 1257226  80%    0.21K  42341       37    338728K xfs_ili
> 1539808 1257748  81%    1.00K  48119       32   1539808K xfs_inode
> 538432 470882  87%    0.50K  16826       32    269216K kmalloc-512
> 403116 403004  99%    0.19K   9598       42     76784K dentry
> 169250 145824  86% 0.31K   6770       25     54160K arp_cache
>
>
> Does it may cause any performance concern ?

I believe that is one of those "it depends" kinds of questions.

> Btw , how could I flush the memory of arp_cache which using by XFS(SWIFT)?

You can use the classic "arp" command to manipulate the ARP cache. It 
can also show you how many entries there are.  I suspect that a web 
search on "linux flush arp cache" may yield some helpful results as well.

rick jones