mmap performance and memory use
wojtek at wojtek.tensor.gdynia.pl
Mon Oct 10 21:28:16 UTC 2011
> Notice that vm.pmap.pde.promotions increased by 31. This means that 31
> superpage mappings were created by promotion from small page mappings.
thank you. i looked at .mappings as it seemed logical for me that is shows
> In contrast, vm.pmap.pde.mappings counts superpage mappings that are created
> directly and not by promotion from small page mappings. For example, if a
> large executable, such as gcc, is resident in memory, the text segment will
> be pre-mapped using superpage mappings, avoiding soft fault and promotion
> overhead. Similarly, mmap(..., MAP_PREFAULT_READ) on a large, memory
> resident file may pre-map the file using superpage mappings.
your options are not described in mmap manpage nor
when can i find the up to date manpage or description?
is it possible to force VM subsystem to operate on superpages when
possible - i mean swapping in 2MB chunks?
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