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Comment: Re:Idiots (Score 1) 219

Even if you dedicated a core and sat in a busy loop polling the NICs for new packets, you'd still have to wait for the receiving NIC to get the whole packet, you'd still have to set up a DMA transfer to ram, you'd still have to look up the address in an O(log n) trie too large to stay in the L3 cache and you'd still have to set up a DMA transfer from ram to the outbound NIC which would still wait for the entire packet before beginning to transmit it.

"Big Iron" routers don't do this. They wait until they have the whole packet. Then the address is looked up in the O(1) TCAM*, a special tri-state static ram that isn't present in your generic x86 machine. Then the packet is transmitted across the backplane to the outgoing interface without ever touching main memory or the the main processor.

Even then the packet tends to get buffered at least twice with a stochastic probability of waiting in the buffer for other traffic to clear. And that's if you're using a high-quality service provider that avoids running links over 80% of capacity.

* TCAM = Ternary Content Addressable Memory. Bits are organized in rows containing an address or subnet. Each bit can have three states: 1, 0 or "don't care." The address to be looked up is injected at the top of the TCAM and compared against all rows in the TCAM during a single clock. The TCAM outputs the position of the first matching row.

Yes, it's a heater.

+ - Samba user survey results - Improve the documentation !->

Submitted by Jeremy Allison - Sam
Jeremy Allison - Sam writes: Mark Muehlfeld of the Samba Team recently surveyed our user base and recently reported the results at the SambaXP conference in Germany.

They make fascinating reading, and include all the comments on Samba made by our users. Short answer — we must improve our documentation. Here are the full results:


                Jeremy Allison,
                Samba Team.

Link to Original Source

Comment: So this means ... (Score 1) 80

... All affected members will receive letters of apology, offering two years of free credit monitoring and identity threat protection as compensation, ...

So they're saying that they have such monitoring/protection, but members who aren't explicitly paying extra for such monitoring/protection aren't being protected from identity theft in any way?

Somehow, I don't find this surprising. But I'm a bit surprised that they'd admit it so blatantly and openly.

(Actually, I'm a bit dubious about their implicit claim to have such monitoring/protection already. But it's fairly common for companies to make such claims for PR purposes, without bothering to actually implement what they're claiming to supply until something like this hits them. Maybe they had another similar incident happen sometime in the past, and are finally getting around to doing something about it?)

(And what exactly does "identity threat protection" mean? Google doesn't seem to have any matches for that phrase, and automatically replaces it with "identity theft protection", which doesn't sound like the same thing at all. ;-)

Comment: Re:Idiots (Score 1) 219

It's not about the number of cores, it's about the expense of the context switches when servicing the interrupt. The x86 architecture doesn't have register banks the way the old Sparc chips did. Every context switch the registers have to be dumped to ram and the new contents loaded from ram. That's an expensive operation.

Comment: Re:Either of the poles woulc cause this effect (Score 1) 468

by Tumbleweed (#49739947) Attached to: The Brainteaser Elon Musk Asks New SpaceX Engineers

If you start a mile north of the South Pole, walk a mile south, then you cannot walk west, so it still fails.

Also, the North Pole isn't ice-free all year long. (I've not been keeping up with how much (if it has happened yet) it is ice-free during a year, but it's certainly not the whole year. Yet.)

"Who alone has reason to *lie himself out* of actuality? He who *suffers* from it." -- Friedrich Nietzsche