netdev - getaddrinfo - too many recvmsg calls

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Message-ID: <dffc28000907200005p7effca1cif4060b15be99e84@mail.gmail.com>
Date:	Mon, 20 Jul 2009 09:05:56 +0200
From:	Zsolt SZALAI <zs.szalai@...il.com>
To:	netdev@...r.kernel.org
Subject: getaddrinfo - too many recvmsg calls

Hi!

I'm working with a host that contains sometimes thousands of virtual
ip address.
One of our third-party application calls getaddrinfo for
sanity-checking the given IP.
I've noticed that recvmsg calls inside getaddrinfo are proportioned to
the number of VIPs, causing high system load and "hanging" user
experience when there are lots of VIPs and also the sanitychecks may
have to happen 2-5 times in a second.

The sanitycheck is now really simple, just a
    addrinfo hints = { 0, AF_INET, 0, 0, 0, NULL, NULL, NULL };
    int result = getaddrinfo(ipAddress, NULL, &hints, &addresses);
call.

I've also noticed that when the vips are configured with `ip` and not
with `ifconfig`, the number of recvmsg calls drops down by a 0.5
multiplier.

Could you advise some other method or optimized execution for this
checks for the environment described?
Or should it be just skipped?

Thanks,
Zsolt Szalai
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