Does posix_fadvice call the broken API sys_fadvice64 or the fixed sys_fadvice64_64?

I'm wanting to experiment with the fadvice functions and reading up discovered 开发者_C百科that there is a sys_fadvice64 function which is obsoleted by sys_fadvice64_64

But, the new function has the same parameters. Why didn't they just fix the old one?

And secondly, does posix_fadvice call the broken API or the fixed one? how can I tell?

The new function uses loff_t for len, whereas the old one uses size_t. To maintain binary compatibility with programs compiled against the old function, a new function was required.

posix_fadvise() should call the new function, if it is available. You can test this by compiling a test program that uses posix_fadvise(), and using the strace utility to see which system call it uses (don't forget to compile with -D_FILE_OFFSET_BITS=64).