On Thu, 2003-10-23 at 01:55, Joakim Tjernlund wrote: > I did a kernel profile(included below) of the bootup of my custom MPC862 > board and I > noticed that __restore_flags gets a very high count. I am suprised that such > a small > assembler routine gets such a high count. __cli, _save_flags_ptr and __sti > are much lower. > A small test program with a tight select loop on fds 0,1 or 2 also makes > __restore_flags > go wild. > Anyone know why? >
Simple: when interrupts are off (typically after a __save_flags), there can't be any profiling interrupts. As soon as you restore the interrupts (_restore_flags), the interrupt used for profiling will fire. -- Gary Thomas <gary at mlbassoc.com> MLB Associates ** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/
