Magnus,
> "anonymous mapped memory" site:microsoft.com > turns out 0 (zero) results. And even splitting it up there > seems to be nearly no information ... is the same thing by > any chance also known by different names? Hmm. Yeah, most likely :) I may have grabbed that name from something else. THe documentation for the call is on http://windowssdk.msdn.microsoft.com/en-us/library/ms685007(VS.80).aspx, we specify INVALID_HANDLE_VALUE for hFile, which means:
[...] CreateFileMapping creates a file mapping object of a specified size that _the operating system paging file backs_ [...] I assume that DWORD dwMaximumSizeHigh and DWORD dwMaximumSizeLow get filled with whatever I configure in shared_memory? My reading of that function gives me the impression, that this kind of shared *memory* is essentially a shared disk file - "_the operating system paging file backs_" Especially documentation lines like "If an application specifies a size for the file mapping object that is larger than the size of the actual named file on disk, the file on disk is increased to match the specified size of the file mapping object." really makes me think that that area is just a comfortable way to access files on disk as memory areas; with the hope of propably better caching then not-memory-mapped files. That would explain my disturbing impressions of performance of PostgreSQL on win32 rising when lowering shared_memory... Harald -- GHUM Harald Massa persuadere et programmare Harald Armin Massa Reinsburgstraße 202b 70197 Stuttgart 0173/9409607 - Python: the only language with more web frameworks than keywords.
