ERROR: could not read block 0 in file "global/XXXXX": Bad address Problem

hi, I have researched buffer manager with postgresql9.4.18. For exact result, I must change IO style to Direct IO. Then I changed the align and O_DIRECT flags according to the version, and set the options at compile time. However, when I run postgres with the modified version, I get ERROR: could

[Tiny Debug Issue] Undefined Reference problem encountered during compile

First of all, thank you for listening to this mail. As I mentioned in the title, I got a undefined reference in compiling time. The reason that I wonder is that I surely add header file for the function. In more detail, I want to use TransactionIdEquals() function in freelist.c file. Then, I