Tru Huynh wrote: > where did you generate your libmy.so? On a C3/4/5 box? > > What gives (on c4 and c5): > ldd libmy.so > > You may miss some compat libs. > > Tru > For the c4 test, I built it on c4, and for the c5 test I built it on c5. Here are the outputs from ldd on the c4 and c5 boxes respectively: [hywel at centos4box]$ ldd libmy.so libstdc++.so.6 => /usr/lib/libstdc++.so.6 (0x00e45000) libm.so.6 => /lib/tls/libm.so.6 (0x00afd000) libgcc_s.so.1 => /lib/libgcc_s.so.1 (0x00a80000) libc.so.6 => /lib/tls/libc.so.6 (0x00267000) /lib/ld-linux.so.2 (0x00a48000) [hywel at centos5box]$ ldd libmy.so linux-gate.so.1 => (0x009ce000) libstdc++.so.6 => /usr/lib/libstdc++.so.6 (0x004e7000) libm.so.6 => /lib/libm.so.6 (0x005fe000) libgcc_s.so.1 => /lib/libgcc_s.so.1 (0x00eae000) libc.so.6 => /lib/libc.so.6 (0x00110000) /lib/ld-linux.so.2 (0x00908000) The .so files work fine, it's only when I later run sprof to get the profile that I have any problem (on the c5 box).