RE: [GD-Windows] XP2 slowdowns?
Brought to you by:
vexxed72
Menu
▾
▴
RE: [GD-Windows] XP2 slowdowns?
|
From: Jon W. <hp...@mi...> - 2004-09-06 15:40:15
|
LUA does not use a JIT, so that's not what it is. Bytecodes are not native x86 instructions; they're just data that the LUA interpreter loop reads and (basically) does a big switch on. Further, the DEP is implemented using hardware traps, the same way as non-writable (or non-mapped) memory is. Thus, the OS doesn't need to spend extra time on it; it flips a bit in the page table, and if you ever try to execute on that page, the CPU will get an interrupt, similar to a segv if you write to un-mapped memory. Sadly, only the very newest, most expensive CPUs support the executable permission bit on the x86 architecture, so most CPUs don't have the ability to trap data execution. Thus, Microsoft added something they call Software-enforced data execution prevention. However, that code only gets run when an exception is triggered (SegV, etc), AND if the binary that triggers the exception is re-compiled to support the checks; all this does is making sure that the exception handler is an address that's a bona fide function export from your binary. If the idle thread is busy, it means that your process is blocked on some blocking primitive (synchronization somewhere) held by some other process. Thus, if there's a high idle CPU utilization, try removing specific calls to Windows APIs until the problem goes away; then you know what changed. Cheers, / h+ -----Original Message----- From: gam...@li... [mailto:gam...@li...]On Behalf Of Brett Bibby Sent: Monday, September 06, 2004 4:12 AM To: gam...@li... Subject: Re: [GD-Windows] XP2 slowdowns? I came across this: http://www.microsoft.com/technet/prodtechnol/winxppro/maintain/sp2mempr.mspx Since our game is script driven (Lua) I'm wondering if that other 50% of Windows CPU time is being used to check the execute permissions of the software Data Execution Prevention (DEP) permission? It specifically cautions JIT code may be broken. We don't mark the page block as executable and load the Lua bytecodes into RAM allocated form the heap. Has anybody else using scripts noticed any performance penalties? Can anybody see any reason why the DEP could be the cause? Thanks, Brett ----- Original Message ----- From: "mike wuetherick" <mi...@ge...> To: <gam...@li...> Sent: Monday, September 06, 2004 12:06 PM Subject: Re: [GD-Windows] XP2 slowdowns? > i've read other reports online about similar slowdowns related to sp2, but > nothing pointing to a specific issue. > > i think it's just windows twiddling with the swap file and other crap - > there needs to be a way to tell windows 'the computer is busy now, dont do > anything until further notice'...i've seen situations where windows > decides to random start defragging mid-game that type of thing. > > just idiotic behavior from such a so-called 'smart os' but i digress. > > unfortunately the only way to probably fix this is to shut down services > that are running maintenance or whatever, which isn't exactly an > 'end-user' fix... > > we updated one machine to sp2 and it was an all-day nightmare, haven't > even considered putting it onto anything else yet. > > the college i teach at isn't going near it for a long time i know as well. > > mike w > www.realityfactory.ca > > Brett Bibby wrote: > >> Hello, >> We upgraded some of our development machines using XP to SP2 and the >> upgraded machines _sometimes_ run our game slower now. When I watch the >> processes while the game runs, the game frequently drops to 20-50% of >> CPU, with the windows idle occupying the other 50%, so our game is >> sometimes not consuming as much of the CPU as desired. Has anybody else >> noticed any speed problems with their games? >> Thanks, >> Brett >> > > > ------------------------------------------------------- > This SF.Net email is sponsored by BEA Weblogic Workshop > FREE Java Enterprise J2EE developer tools! > Get your free copy of BEA WebLogic Workshop 8.1 today. > http://ads.osdn.com/?ad_id=5047&alloc_id=10808&op=click > _______________________________________________ > Gamedevlists-windows mailing list > Gam...@li... > https://lists.sourceforge.net/lists/listinfo/gamedevlists-windows > Archives: > http://sourceforge.net/mailarchive/forum.php?forum_id=555 ------------------------------------------------------- This SF.Net email is sponsored by BEA Weblogic Workshop FREE Java Enterprise J2EE developer tools! Get your free copy of BEA WebLogic Workshop 8.1 today. http://ads.osdn.com/?ad_id=5047&alloc_id=10808&op=click _______________________________________________ Gamedevlists-windows mailing list Gam...@li... https://lists.sourceforge.net/lists/listinfo/gamedevlists-windows Archives: http://sourceforge.net/mailarchive/forum.php?forum_id=555 |
