Re: [PLEASE-TESTME] Zerocopy networking patch, 2.4.0-1

Manfred Spraul (manfred@colorfullife.com)
Wed, 10 Jan 2001 13:03:56 +0100


Ingo Molnar wrote:
>
> On Wed, 10 Jan 2001, Manfred Spraul wrote:
>
> > That means sendmsg() changes the page tables? I measures
> > smp_call_function on my Dual Pentium 350, and it took around 1950 cpu
> > ticks.
>
> well, this is a performance problem if you are using threads. For normal
> processes there is no need for a SMP cross-call, there TLB flushes are
> local only.
>
But that would be ugly as hell:
so apache 2.0 would become slower with MSG_NOCOPY, whereas samba 2.2
would become faster.

Is is possible to move the responsibility for maitaining the copy to the
caller?

e.g. use msg_control, and then the caller can request either that a
signal is sent when that data is transfered, or that a variable is set
to 0.

--
	Manfred
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
Please read the FAQ at http://www.tux.org/lkml/