The llseek scalability issue was caused by the Linux kernel taking a lock on a data structure when no such lock was necessary. While it is possible that FreeBSD has the same problem with llseek, I see no reason to assume that is the case.
FreeBSD probably works as well as Linux >= 3.2 when it comes to llseek, but there might have some other scalability issue which is not present in Linux.
EDIT: Here is a link to the Linux kernel patch, PostgreSQL uses SEEK_END to check the file sizes.
FreeBSD probably works as well as Linux >= 3.2 when it comes to llseek, but there might have some other scalability issue which is not present in Linux.
EDIT: Here is a link to the Linux kernel patch, PostgreSQL uses SEEK_END to check the file sizes.
https://lkml.org/lkml/2011/9/15/401