Re: [PATCH v9 net-next 5/7] net: simple poll/select low latencysocket poll

[Eric Dumazet]

On Wed, 2013-06-05 at 16:41 +0300, Eliezer Tamir wrote:
> On 05/06/2013 16:30, Eric Dumazet wrote:

> > I am a bit uneasy with this one, because an applicatio polling() on one
> > thousand file descriptors using select()/poll(), will call sk_poll_ll()
> > one thousand times.
> 
> But we call sk_poll_ll() with nonblock set, so it will only test once
> for each socket and not loop.
> 
> I think this is not as bad as it sounds.
> We still honor the time limit on how long to poll.

We still call ndo_ll_poll() a thousand times, and probably do a
spinlock/unlock a thousand times in the driver.

I would definitely be convinced if you give us some performance numbers
of a poll() on a thousand tcp sockets for example.

See my following mail about sk_poll_ll()

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