Re: high cpu load with tcpdump

[christos%zoulas.com@localhost (Christos Zoulas)]

On Mar 1,  3:08pm, 6bone%6bone.informatik.uni-leipzig.de@localhost (6bone%6bone.informatik.uni-leipzig.de@localhost) wrote:
-- Subject: Re: high cpu load with tcpdump

| On Mon, 29 Feb 2016, Christos Zoulas wrote:
| 
| >
| > This tcpdump ktrace is when bind is running, right?
| > What happens if you stop it? How does the ktrace look then?
| > Or once you start bind, tcpdump goes nuts and stays that way?
| 
| You're right. When tcpdump is started after the bind, tcpdump caused 
| problems.
| 
| 
| Here the ktrace (tcpdump before bind)
| 
|    3451      1 tcpdump  1456839639.234979724 RET   read 0
|    3451      1 tcpdump  1456839639.234983565 CALL  read(3,0x7f7ff7b16000,0x80000)
|    3451      1 tcpdump  1456839640.235319234 GIO   fd 3 read 0 bytes      ""
|    3451      1 tcpdump  1456839640.235322516 RET   read 0
|    3451      1 tcpdump  1456839640.235328872 CALL  read(3,0x7f7ff7b16000,0x80000)
|    3451      1 tcpdump  1456839641.235662445 GIO   fd 3 read 0 bytes      ""
|    3451      1 tcpdump  1456839641.235665868 RET   read 0
|    3451      1 tcpdump  1456839641.235670128 CALL  read(3,0x7f7ff7b16000,0x80000)
|    3451      1 tcpdump  1456839642.236012990 GIO   fd 3 read 0 bytes      ""
|    3451      1 tcpdump  1456839642.236017460 RET   read 0
|    3451      1 tcpdump  1456839642.236021371 CALL  read(3,0x7f7ff7b16000,0x80000)
|    3451      1 tcpdump  1456839643.236348030 GIO   fd 3 read 0 bytes      ""
| 
| 
| In this case all works fine. There is also no change in the bind ktrace.
| 

Hmm, need to find a way to reproduce it...

christos