thread problem with libc for Linux

Hi, I am using RedHat 6.2, gcc 2.95.2(libc.so.6). I have a problem runing threads on Linux. I build the application with the following line: g++ -D_REENTRANT -D_UNIX -DXML_LINUX -o tapp \ testt.c unixfileio.cpp -lpthread The program is creating a certain number of threads, then

how mmap() works?

Hi, mmap() creates a mmaped memory associated with a physical file. If a process updates the mmaped memory, Linux will updates the file "automatically". If this is the case, why do we need msync()? If this is not the case, what is the interval between 2 "WRITE" (IO request operation) request to