From: Ben Greear <greearb@xxxxxxxxxxxxxxx>
Date: Tue, 10 Jun 2003 18:15:36 -0700
What determines whether or not we use the "TSC do_gettimeofday". Does
it automagically happen when you compile for P-III or something like
that?
The 2.5.x kernel has x86 platform drivers that decide this.
And how big of a "bigger box" are you talking about...regular old
SMP, or NUMA?
Many laptops cannot even use TSC reliably because of power management
etc. issues.
> SO_RECVSTAMP, any socket on the machine can ask for this.
Do we know when we are being asked for this value?
We have to take the timestamp at netif_receive_skb() for it to
be accurate.
We don't even know if this packet is for this host until a long
time later, let alone whether any local sockets want SO_RECVSTAMP
or whether any IP options want timestamp or whether tcpdump is
listening etc.
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