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Author Topic: Meltdown and Spectre related performance degradation  (Read 16711 times)

deanon

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Meltdown and Spectre related performance degradation
« on: January 09, 2018, 09:26:15 pm »
Hi guys, after installing windows patch related to subj, compiler performance has degradated dramatically, about 8 times for my project. Before its build was taking about 5 sec, now it is about 40 sec (!). Not to mention, I have all files and build process set up on RAMdrive. Could you please tell me there are some good news about this ahead? I've chosen fpc for this project especially because of its speed, now this advangage seems to be lost...

molly

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Re: Meltdown and Spectre related performance degradation
« Reply #1 on: January 09, 2018, 09:32:44 pm »
Was already wondering when somebody would take this as an excuse to try bash fpc.  :)

These cpu fixes apply to the whole performance of your machine. It shows up in your face in a a more obvious way when compiling. But, any compiler would suffer from this and as such is not fpc/lazarus related.

If that is reason for you to not choose fpc for your projects then i wish you a good of luck with using any other compiler/language. You'll notice that performance penalties are worse there as it accumulates. Worse before means more worse after patching.

deanon

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Re: Meltdown and Spectre related performance degradation
« Reply #2 on: January 09, 2018, 09:37:57 pm »
That is not excuse.
Compiler actually has nothing to do with system api calls (which is the cause of slowdown), the only reason for it is affected by patch, is that compiler do use api calls where they are not necessary. Compiler's work is to build an executable. I believe fpc slows down that much because its operation is based on files w/o abstraction.

molly

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Re: Meltdown and Spectre related performance degradation
« Reply #3 on: January 09, 2018, 09:41:36 pm »
Please read up on spectre and meltdown issues. The cause has nothing to do with system api calls. Where do you get your information from ?

lainz

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Re: Meltdown and Spectre related performance degradation
« Reply #4 on: January 09, 2018, 09:44:12 pm »
Meltdown and Spectre has only issues with FPC everyone knows that molly! If you use C it works fine =)

Go and use C.  ;D

molly

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Re: Meltdown and Spectre related performance degradation
« Reply #5 on: January 09, 2018, 09:46:35 pm »
@lainz:
You use compelling arguments... i think you convinced me. I'll start using c now ;D

Any hint on where to find me a c compiler that does not use system api calls ?  >:D
« Last Edit: January 09, 2018, 09:48:42 pm by molly »

Thaddy

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Re: Meltdown and Spectre related performance degradation
« Reply #6 on: January 09, 2018, 09:49:00 pm »
Meltdown and Spectre has only issues with FPC everyone knows that molly! If you use C it works fine =)

Go and use C.  ;D
WHAT! FPC doesn't even optimize for pipe lined code!  Do not ever never give an ill informed answer.  A wrong answer is OK, but never ever without knowing what you are talking about. <2018  >:( >:(>
Sheer stupitity when you follow this: https://twitter.com/brainsmoke/status/948561799875502080
« Last Edit: January 09, 2018, 09:55:02 pm by Thaddy »
Specialize a type, not a var.

deanon

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Re: Meltdown and Spectre related performance degradation
« Reply #7 on: January 09, 2018, 09:49:45 pm »
Well then tell me please what it has to do with.
It is directly bound to system api call, because most of file operations are executing on kernel level (syscall).

lainz

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Re: Meltdown and Spectre related performance degradation
« Reply #8 on: January 09, 2018, 09:50:51 pm »
Meltdown and Spectre has only issues with FPC everyone knows that molly! If you use C it works fine =)

Go and use C.  ;D
WHAT! FPC doesn't even optimize for pipe lined code!  Do not ever never give an ill informed answer.  A wrong answer is OK, but never ever without knowing what you are talking about. <2018  >:( >:(>

Thaddy did you see the icon I posted, it was a joke, if anyone thinks that obviously is not well informed at all!

lainz

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Re: Meltdown and Spectre related performance degradation
« Reply #9 on: January 09, 2018, 09:54:36 pm »
@lainz:
You use compelling arguments... i think you convinced me. I'll start using c now ;D

Any hint on where to find me a c compiler that does not use system api calls ?  >:D

=)

I remember because I stopped making jokes.  ::) But at least with the first part of the response you are the only one that maybe got it was a joke?

Thaddy

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Re: Meltdown and Spectre related performance degradation
« Reply #10 on: January 09, 2018, 09:56:24 pm »
@lainz:
You use compelling arguments... i think you convinced me. I'll start using c now ;D

Any hint on where to find me a c compiler that does not use system api calls ?  >:D

=)

I remember because I stopped making jokes.  ::) But at least with the first part of the response you are the only one that maybe got it was a joke?
https://twitter.com/brainsmoke/status/948561799875502080 .....  >:D :D :D

It is not a joke.... It works...
Specialize a type, not a var.

molly

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Re: Meltdown and Spectre related performance degradation
« Reply #11 on: January 09, 2018, 10:07:10 pm »
Well then tell me please what it has to do with.
It is directly bound to system api call, because most of file operations are executing on kernel level (syscall).
Spectre... meltdown

Where does it read that those are system api call related ?

They are cpu related issues. If the OS patches it in such a way that OS performance get affected then it affects the whole performance of that OS, and not for FPC alone. The implication that you try to make there simply does not make any sense (even if you would have been correct)

@lainz:
Yups, got you there right from the start  :)
« Last Edit: January 09, 2018, 10:09:39 pm by molly »

deanon

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Re: Meltdown and Spectre related performance degradation
« Reply #12 on: January 09, 2018, 10:10:22 pm »
Well then tell me please what it has to do with.
It is directly bound to system api call, because most of file operations are executing on kernel level (syscall).
Spectre... meltdown

Where does it read that those are system api call related ?

They are cpu related issues. If the OS patches it in such a way that OS performance get affected then it affects the whole performance of that OS, and not for FPC alone. The implication that you try to make there simply does not make any sense (even if you would have been correct)

molly, do you contribute to fpc development? If not, please do not post in this topic, if yes, please leave the team.

lainz

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Re: Meltdown and Spectre related performance degradation
« Reply #13 on: January 09, 2018, 10:16:10 pm »
@lainz:
Yups, got you there right from the start  :)

Thanks.

Of course I protected my PC's and the browser.

BTW I did not notice too much slow down.

molly, do you contribute to fpc development? If not, please do not post in this topic, if yes, please leave the team.

And you? People is trying to explain you that if it slow down something, is for everything not just FPC.

deanon

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Re: Meltdown and Spectre related performance degradation
« Reply #14 on: January 09, 2018, 10:24:18 pm »
lainz, people do not try to explain, they try to excuse for flaw that was suddenly discovered due to environmental conditions, and convince that it is okay. I just would like to know if someone is going to take care about it, because degradation is incomparable to average shown by benchmarks on the net. 30% is not 800%

 

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