MMAP&multiprocessor machine question
Wojciech Puchar
wojtek at tensor.3miasto.net
Thu Apr 13 16:39:00 UTC 2006
assume i have my program, that accesses data using mmap interface only, is
run many times on same machine.
if it's uniprocessor machine, it's clear - all processes will see the data
coherrent.
what in case of more than one processor. will one processor keep in cache
data that was already modified by other?
is there any system call to FORCE synchronization when it's needed on
given page?
on my dual pentium II machine it looks like data being always coherent,
but how it will be on other architectures/models? for example MIPS
processors has software managed caches - will my program work wrong on
such hardware?
for now - it's ok because it works, but i won't like to be surprised say 5
years after because my program breaks important data on some new machine
it may run at.
it's multiuser database program (or will be, as it's in beginning phase)
so such behaviour is inacceptable.
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