Kernel migration eat CPUs

Alexey Vlasov
2013-08-22T15:02:46Z

Hi,

Beginning from 3.7 including 3.10 kernel, I noticed that from time to
time all CPUs turn out to be busy 100% and at the moment websites of my
clients work slowly or don’t work at all.

top screen:
https://www.dropbox.com/s/psuk2cwn6exinyd/3.9.cpu_migration.jpg

All CPUs are busy with kernel threads migration for about 3-5 minutes.
Exactly how often it periodically happens I don’t know, but it happens
once in 1-3 hours.

Approximately 30 my servers work on kernel 2.6.35 and there’s no such
problem there. We use kernels 3.7 – 3.9 on 5 servers and I see such
effect everywhere. If you downgrade on 2.6.35, then migration doesn’t
eat CPUs.

These servers are used for usual LAMP shared hosting.

Can I get migration as if on the kernel 2.6.35 or can this feature be
disabled?

--
BRGDS. Alexey Vlasov.
jabber: renton@1gb.ru
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