Re: hires timestamps for netif_rx()

From: Andi Kleen (ak@suse.de)
Date: Fri Jan 18 2002 - 15:14:08 EST


On Fri, Jan 18, 2002 at 12:09:05PM -0800, David S. Miller wrote:
> From: Andi Kleen <ak@suse.de>
> Date: Fri, 18 Jan 2002 15:01:20 +0100
>
> Unfortunately gettimeofday at least on i386 has a readlock. It would
> add a new cache line bouncing bottleneck for every packet.
>
> Andi, i386 SMP? :-)

If you used do_gettimeofday unconditionally then everybody would eat the readlock, not
only i386 (unless you change it to be lockless first like andrea did for the
x86-64 vsyscall version)

If you didn't propose to use it unconditionally then I misunderstood you and I apologize.

-Andi
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