Re: Memory leak in ip_dst_cache

Yes Eric, this command doesn't work on 2.6.24. Which timer are you suspecting?


----- Original Message -----
From: Eric Dumazet <redacted>
To: Kumar S <redacted>
Cc: netdev <redacted>
Sent: Friday, September 9, 2011 3:08 PM
Subject: Re: Memory leak in ip_dst_cache

Le vendredi 09 septembre 2011 à 14:58 -0700, Kumar S a écrit :

I agree, 3 MB is not a concern. But actually this is exceeding, we are
seeing more than 1200000 objects in a span of 24 hours, which is close
to 300 MB.

Hmm, please include netdev in your mails.

Then there is something else.

Maybe a timer bug preventing dst_gc_task() to make its duty.

 Other tasks require somewhere around 200 MB+. When it reaches this
number, the board reboots. In lab we could simulate this. That is how
I'm trying to understand the problem. I'm injecting around 10k routes,
and waiting for them to ageout.
 

I dont know, you could try disable IP route cache.

On recent (2.6.29+) kernels, thats very easy

# Disable Ip route cache (negative value in rebuild_count)
echo 3000000000 >/proc/sys/net/ipv4/rt_cache_rebuild_count

On an old kernel, you probably need to patch your kernel, or backport
commit 1080d709fb9d8cd43 (net: implement emergency route cache rebulds
when gc_elasticity is exceeded)