3 ms·

Your operating system hits memory pressure and pages your RAM page to disk. Some time later it restores it. Hey, look, you've suddenly had an arbitrarily long d

Your operating system hits memory pressure and pages your RAM page to disk. Some time later it restores it. Hey, look, you've suddenly had an arbitrarily long delay. So you can't always finish early. Also, even assuming you can always finish early, that plan won't prevent, for example, measuring the delay of other responses. (As your process sleeping will have an impact on how fast other responses are sent. Due to cache pressure, in particular. But also due to CPU throttling, scheduling, etc, etc.

mreiland 12y ago
Why is it people can't ever respond to sanity, but instead assume idiocy? You measure page faults in terms of milliseconds, I was not suggesting you even out the cryptographic timings to the tune of milliseconds, especially when you consider most cryptographic functions are setup specifically to take longer than that. There is a delta that you can come up with such that things like page faults fall within it and it would still have acceptable performance. All but the most pounded of servers would be able to fall within it with no problem whatsoever.
- TheLoneWolfling 12y ago
  You completely missed my second point there - that even if you can afford to take the performance hit it still doesn't solve the problem. And most of the cryptographic functions we're talking about here are things for webservers, where low performance leaves you open to easy (D)DOSing.
  - mreiland 12y ago
    You haven't explained why it doesn't solve the problem. My experience has been if I can't understand it, it's because it's bullshit. So why not take another crack at explaining why that wouldn't solve the problem? And don't complain to me about DDOS, people specifically code cryptographic functions to take longer than they absolutely have to. If they're not worried about DDOS, neither are we for the purposes of this conversation.

mreiland 12y ago

Why is it people can't ever respond to sanity, but instead assume idiocy? You measure page faults in terms of milliseconds, I was not suggesting you even out the cryptographic timings to the tune of milliseconds, especially when you consider most cryptographic functions are setup specifically to take longer than that. There is a delta that you can come up with such that things like page faults fall within it and it would still have acceptable performance. All but the most pounded of servers would be able to fall within it with no problem whatsoever.

TheLoneWolfling 12y ago
You completely missed my second point there - that even if you can afford to take the performance hit it still doesn't solve the problem. And most of the cryptographic functions we're talking about here are things for webservers, where low performance leaves you open to easy (D)DOSing.
- mreiland 12y ago
  You haven't explained why it doesn't solve the problem. My experience has been if I can't understand it, it's because it's bullshit. So why not take another crack at explaining why that wouldn't solve the problem? And don't complain to me about DDOS, people specifically code cryptographic functions to take longer than they absolutely have to. If they're not worried about DDOS, neither are we for the purposes of this conversation.