Linked by Thom Holwerda on Wed 29th Aug 2007 00:28 UTC, submitted by diegocg
Windows Robert Love, a famous Linux kernel hacker, has written a blog entry with his thoughs on the recently posted Vista's network slowdown issue and the explanation given by Mark Russinovich: "Unlike DPCs, however, the Linux parallel does not consume nearly half of your CPU. There is no excusable reason why processing IP packets should so damagingly affect the system. Thus, this absolutely abysmal networking performance should be an issue in and of itself, but the Windows developers decided to focus on a secondary effect."
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RE: Driver Quality
by segedunum on Wed 29th Aug 2007 08:29 UTC in reply to "Driver Quality"
segedunum
Member since:
2005-07-06

I suspect that the Linux vs. Windows difference is more in the drivers.

Microsoft tried to do the same thing with NT 4 on a lot of occasions - try to blame third-party drivers.

It would be interesting to find out Mark's network controller, driver, and driver option settings. I believe Windows could do much better than 40% if most of the work was done on the network controller, as it should be.

That's exactly what Vista's network stack is supposed to do - offload to TOE. However, all that it's done is increase the complexity of the networking stack, drivers and the possibilities of things to go wrong.

The Linux guys quite rightly rejected TOE because there was a lot of pain with zero benefit to anyone.

Reply Parent Score: 4

RE[2]: Driver Quality
by kaiwai on Wed 29th Aug 2007 10:13 in reply to "RE: Driver Quality"
kaiwai Member since:
2005-07-06

That's exactly what Vista's network stack is supposed to do - offload to TOE. However, all that it's done is increase the complexity of the networking stack, drivers and the possibilities of things to go wrong.

The Linux guys quite rightly rejected TOE because there was a lot of pain with zero benefit to anyone.


Based on what evidence? TOE is beneficial only for situations where the bandwidth utilisation is so high there are major performance penalties associated with processing huge amounts of TCP/IP information coming in. Heck, right now, for example, talk to anyone with incredibly large systems and the amount of CPU utilisation due to the amount of traffic.

Using the rationale of the 'Linux experts' - encryption acceleration and XML parsing acceleration are all a waste of time. Waste of time or more like, a complex problem that requires a design from the ground up for it to work properly. Something demonstrated in the number of re-writes of Linux subsystems because inadequate of designing before writing the code.

Reply Parent Score: 4

RE[3]: Driver Quality
by segedunum on Wed 29th Aug 2007 11:06 in reply to "RE[2]: Driver Quality"
segedunum Member since:
2005-07-06

Based on what evidence? TOE is beneficial only for situations where the bandwidth utilisation is so high there are major performance penalties associated with processing huge amounts of TCP/IP information coming in.

Look at the history of networking. People have been talking about TOE for years, even with 10 and 100 networks, and it has never come about because CPUs and hardware in general have kept pace. TOE also dramatically increases the cost and complexity of network cards, drivers and stacks for no benefit. Additionally, in some cases it may not even increase performance at all, because of extra communication between the network card and the rest of the system.

Networking is supposed to just work, not get reinvented. It is no reason to completely redesign and rewrite a network stack and all the associated drivers. TOE has not been proven to offer any benefit whatsoever.

Mind you, from what Mark Russinovitch showed, it isn't doing a good job of keeping CPU usage down!

Using the rationale of the 'Linux experts' - encryption acceleration and XML parsing acceleration are all a waste of time.

Depends on what the cost/benefit is.

Something demonstrated in the number of re-writes of Linux subsystems because inadequate of designing before writing the code.

You misunderstand. That's called iterative improvement. People ask themselves if there is a pay-off in the long run and it is usually done without affecting anything else or rewriting ten dozen drivers.

It's how Linux keeps improving, and how, quite frankly, systems like Vista and Solaris don't.

Edited 2007-08-29 11:12

Reply Parent Score: 3

RE[3]: Driver Quality
by diegocg on Thu 30th Aug 2007 14:15 in reply to "RE[2]: Driver Quality"
diegocg Member since:
2005-07-08

Based on what evidence?


The TOE issue has been discussed to death, search the archives. This is a design decision that has not been taken randomly, there're strong reasons to argue that implementing TOE is stupid and a waste of time.

Reply Parent Score: 2

RE[2]: Driver Quality
by Soulbender on Wed 29th Aug 2007 10:49 in reply to "RE: Driver Quality"
Soulbender Member since:
2005-08-18

"The Linux guys quite rightly rejected TOE because there was a lot of pain with zero benefit to anyone."

There's no evidence that TOE is the cause of this problem.

Reply Parent Score: 2

RE[3]: Driver Quality
by segedunum on Wed 29th Aug 2007 11:09 in reply to "RE[2]: Driver Quality"
segedunum Member since:
2005-07-06

There's no evidence that TOE is the cause of this problem.

I never said it was (it was a specific reply) - but something in the network stack is definitely wrong because this didn't happen in XP.

Edited 2007-08-29 11:15

Reply Parent Score: 2