I have a program which uses mmap() and shared memory to efficiently access a large database file. I would like to experiment with huge pages to see if it speeds things up.
I thought that a quick and easy way would be to copy the database file into Linux's hugetlbfs directory and make a symlink to it in the old location.
However, this does not work because the cp command cannot write to the file. I suspect that files can only be created by calling the ftrunc() and mmap() system calls to write into it. I will probably try writing a copy tool that does this, unless I get an answer describing an existing tool.
I'm looking for any other good methods to do shared memory maps using huge pages in Linux.
