From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ben Greear Subject: Re: gettime: Was (Re: Route cache performance under stress Date: Wed, 11 Jun 2003 08:57:24 -0700 Sender: netdev-bounce@oss.sgi.com Message-ID: <3EE75164.8030500@candelatech.com> References: <3EE682B8.8060708@candelatech.com> <20030610.182234.74725315.davem@redhat.com> <3EE68B15.60802@candelatech.com> <20030610.203325.41658167.davem@redhat.com> <20030611065255.L39678@shell.cyberus.ca> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Cc: "David S. Miller" , netdev@oss.sgi.com Return-path: To: Jamal Hadi In-Reply-To: <20030611065255.L39678@shell.cyberus.ca> Errors-to: netdev-bounce@oss.sgi.com List-Id: netdev.vger.kernel.org Jamal Hadi wrote: > Ok, time to go into another separate thread ;-> > > Sounds like a good idea. > > if (skbneedstimestamp) > do_gettimeofday(&skb->stamp); > else > defertimestamp() > > For defertimestamp() would it be feasible that you store only the > jiffies value in the skb then get timeofday later and somehow > compensate for the difference? Seems very doable to me. > > Question is when do you decide skbneedstimestamp? > Is it when the device is in promiscous mode or do it in ip or icmp etc? > > cheers, > jamal Jiffies is not nearly precise enough. You need something with usec precision at least. If we make a macro to read the value (converting as needed), and just change all the readers to use that macro, then we don't have to make any interesting decisions in the networking core. Ben -- Ben Greear President of Candela Technologies Inc http://www.candelatech.com ScryMUD: http://scry.wanfear.com http://scry.wanfear.com/~greear