I've been digging into why buildfarm member thrush has been dumping core consistently during the regression tests since the posix_fadvise patch went in. I've confirmed that posix_fadvise() itself will SIGSEGV in a standalone test program, and found that this happens only if _FILE_OFFSET_BITS=64 ... which is our default configuration on Linux.
Some googling turned up the following http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=313219 which basically says that posix_fadvise64 + 2.4 kernel + older glibc = crash. It sounds like the 2.4 kernel hasn't got this call but glibc thought it did, up till about a year ago. While we could possibly come up with a suitable configure test to determine whether posix_fadvise is actually safe to use on a given system, I think we should seriously consider just reverting the patch. As far as I saw, zero evidence was given that it actually does anything measurable. Without a benchmark to prove that it's worth spending more time on, I'm disinclined to trouble over it. regards, tom lane ---------------------------(end of broadcast)--------------------------- TIP 2: Don't 'kill -9' the postmaster
