Date: Wed, 24 Sep 2008 12:53:31 -0700 From: John-Mark Gurney <jmg@funkthat.com> To: gnn@freebsd.org Cc: net@freebsd.org Subject: Re: Proposed patch, convert IFQ_MAXLEN to kernel tunable... Message-ID: <20080924195331.GQ783@funkthat.com> In-Reply-To: <m2skrq7jb1.wl%gnn@neville-neil.com> References: <m2skrq7jb1.wl%gnn@neville-neil.com>
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George V. Neville-Neil wrote this message on Tue, Sep 23, 2008 at 15:29 -0400:
> It turns out that the last time anyone looked at this constant was
> before 1994 and it's very likely time to turn it into a kernel
> tunable. On hosts that have a high rate of packet transmission
> packets can be dropped at the interface queue because this value is
> too small. Rather than make a sweeping code change I propose the
> following change to the macro and updating a couple of places in the
> IP and IPv6 stacks that were using this macro to set their own global
> variables.
The better solution is to resurrect rwatson's patch that eliminates the
interface queue, and does direct dispatch to the ethernet driver..
Usually the driver has a queue of 512 or more packets already, so putting
them into a second queue doesn't provide much benefit besides increasing
the amount of locking necessary to deliver packets...
--
John-Mark Gurney Voice: +1 415 225 5579
"All that I will do, has been done, All that I have, has not."
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