From: Oliver Hartkopp <oliver@hartkopp.net>
To: Patrick Ohly <patrick.ohly@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>,
Eric Dumazet <dada1@cosmosbay.com>,
"netdev@vger.kernel.org" <netdev@vger.kernel.org>,
Octavian Purdila <opurdila@ixiacom.com>,
Stephen Hemminger <shemminger@vyatta.com>,
Ingo Oeser <netdev@axxeo.de>,
"Ronciak, John" <john.ronciak@intel.com>
Subject: Re: [RFC PATCH 00/13] hardware time stamping + igb example implementation
Date: Thu, 13 Nov 2008 07:15:48 +0100 [thread overview]
Message-ID: <491BC614.9050201@hartkopp.net> (raw)
In-Reply-To: <491B4BE3.3010104@linux.intel.com>
Andi Kleen wrote:
> Eric Dumazet wrote:
>
>> I threw a "crazy idea", that can be changed if necessary, say with a
>> cookie
>> that identifies the slot in NIC driver structure. O(1) lookup if
>> really needed.
>
> I think "crazy" describes it well because it would be a lot of dubious
> and likely not performing well effort just to save 8 bytes.
Patrick,
one question about a new crazy idea:
If we would tend to add new space in the skb, won't 4 bytes enough then?
A 32 bit value gives a nsec resolution of 4.294967296 seconds or +/-
2.147483648 seconds.
If we make a 'full qualified' 64 bit sys-timestamp available anyway, the
new 32 bit value could be used as an offest (or it could be given to the
userspace directly) to calculate the hw timestamp within the
sys-timestamp context, right?
Regards,
Oliver
next prev parent reply other threads:[~2008-11-13 6:15 UTC|newest]
Thread overview: 48+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-11-11 14:44 [RFC PATCH 00/13] hardware time stamping + igb example implementation Patrick Ohly
2008-10-22 8:17 ` [RFC PATCH 02/13] extended semantic of sk_buff::tstamp: lowest bit marks hardware time stamps Patrick Ohly
2008-11-12 7:41 ` Eric Dumazet
2008-11-12 8:09 ` Patrick Ohly
2008-11-12 10:09 ` David Miller
2008-11-12 9:58 ` David Miller
2008-11-19 12:50 ` Patrick Ohly
2008-10-22 12:46 ` [RFC PATCH 01/13] put_cmsg_compat + SO_TIMESTAMP[NS]: use same name for value as caller Patrick Ohly
2008-11-12 9:55 ` David Miller
2008-10-22 15:01 ` [RFC PATCH 03/13] user space API for time stamping of incoming and outgoing packets Patrick Ohly
2008-11-12 10:02 ` David Miller
2008-10-24 13:41 ` [RFC PATCH 04/13] net: implement generic SOF_TIMESTAMPING_TX_* support Patrick Ohly
2008-11-11 23:15 ` Octavian Purdila
2008-11-12 8:38 ` Patrick Ohly
2008-10-24 13:49 ` [RFC PATCH 05/13] ip: support for TX timestamps on UDP and RAW sockets Patrick Ohly
2008-11-12 9:59 ` David Miller
2008-10-29 14:48 ` [RFC PATCH 06/13] workaround: detect time stamp when command flags are expected Patrick Ohly
2008-11-12 10:00 ` David Miller
2008-10-31 11:43 ` [RFC PATCH 07/13] net: add SIOCSHWTSTAMP - hardware time stamping of packets Patrick Ohly
2008-10-31 12:21 ` [RFC PATCH 08/13] igb: stub support for SIOCSHWTSTAMP Patrick Ohly
2008-11-04 9:23 ` [RFC PATCH 09/13] clocksource: allow usage independent of timekeeping.c Patrick Ohly
2008-11-12 10:04 ` David Miller
2008-11-04 9:27 ` [RFC PATCH 10/13] igb: infrastructure for hardware time stamping Patrick Ohly
2008-11-05 9:58 ` [RFC PATCH 11/13] time sync: generic infrastructure to map between time stamps generated by a clock source and system time Patrick Ohly
2008-11-11 16:18 ` Andi Kleen
2008-11-12 8:01 ` Patrick Ohly
2008-11-12 10:08 ` David Miller
2008-11-12 16:14 ` Patrick Ohly
2008-11-12 16:28 ` Eric Dumazet
2008-11-12 10:05 ` David Miller
2008-11-06 11:13 ` [RFC PATCH 12/13] igb: use clocksync to implement hardware time stamping Patrick Ohly
2008-11-07 9:26 ` [RFC PATCH 13/13] skbuff: optionally store hardware time stamps in new field Patrick Ohly
2008-11-12 16:06 ` [RFC PATCH 00/13] hardware time stamping + igb example implementation Andi Kleen
2008-11-12 16:25 ` Patrick Ohly
2008-11-12 18:44 ` Oliver Hartkopp
2008-11-12 19:22 ` Eric Dumazet
2008-11-12 20:23 ` Andi Kleen
2008-11-12 20:23 ` Andi Kleen
2008-11-12 20:56 ` Eric Dumazet
2008-11-12 21:34 ` Andi Kleen
2008-11-12 22:26 ` Oliver Hartkopp
2008-11-13 15:53 ` Ohly, Patrick
2008-11-13 6:15 ` Oliver Hartkopp [this message]
2008-11-13 6:29 ` Eric Dumazet
2008-11-13 16:05 ` Ohly, Patrick
2008-11-16 8:15 ` Andrew Shewmaker
2008-11-12 22:17 ` David Miller
2008-11-19 12:39 ` Patrick Ohly
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