Messages in this thread | | | Date | Sat, 10 Jan 2015 11:46:27 +0100 | From | Andreas Mohr <> | Subject | Re: Linux 3.19-rc3 |
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Linus Torvalds wrote: > I dunno. I do know that you definitely don't want to haev a > desktop/workstation with 64kB pages.
Yet that is what any VirtualAlloc() call on Windows does (well, not exactly *page* granularity but *allocation* granularity there). Prime example: do a naively specific/custom VirtualAlloc() request for a simple string Hello World\0 allocation (11+1 bytes), get one page (4kB, "Private Data") plus "overhead" (60kB, "Unusable"). --> allocation efficiency: 0.01831%(!). And that does hurt plenty IME, especially on a 32bit address space's very limited 2GB/3GB total per Win32 process.
http://blogs.microsoft.co.il/sasha/2014/07/22/tracking-unusable-virtual-memory-vmmap/ "Why is address space allocation granularity 64K?" http://blogs.msdn.com/b/oldnewthing/archive/2003/10/08/55239.aspx
One thing less left to wonder why 'doze is such a performance pig...
Andreas Mohr
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