Filipa Duarte wrote: > Hi, > > I am running MontaVista embedded Linux 2.4.20 on a > Xilinx ML300 board with a PPC. I am receiving a file > of 50 MB over Bluetooth. I profiled the application Are you using KFI for this profiling? If so, you should be aware that KFI over-reports the time for functions which don't appear to return. This may be the case with __sti_end. > I understand that the function I created called > 'my_memcpy' is one that takes more time. However I do > not really understand what the '__sti_end' and '__sti' > do. I think they are interrupts, but when do these > interrupts happen and why? If I profile the system > doing nothing, these functions are again on top of the > list: > 70055 total 0.0399 > 69868 __sti_end 2183.3750 > I tried to find info on Google about these functions > but I couldn't find anything useful. I tried the file > where these symbols are exported and it did not help. > Does anyone have a pointer for me to start understand > what these functions are for? __sti_end is likely expanding from the macro sti() in 2.4. It is usually inline, but may be UN-inlined due to the presence of the tracing options. (KFI uses the gcc option -finstrument-functions, which will do funny things with the inline definitions.) If you are using KFI I would ignore the data related to __sti and __sti_end as it is probably anomolous. With regard to what these functions are (if you're still interested), cli() disables interrupts and sti() enables interrupts. These routines are meant to be the architecture independent routines to replace similarly-named x86 instructions for this operations. Interrupts happen thousands of times a second on an x86 platform, and it is not unusual to see them in your trace. (They are generated by the hardware and appear to come out of nowhere.) IRCC, you can turn off tracing of interrupt context for a KFI log using "filter noints" or some such thing. Hope this is relevant and helps. If you're not using MontaVista's KFI, then please ignore... Regards, -- Tim ============================= Tim Bird Architecture Group Chair, CE Linux Forum Senior Staff Engineer, Sony Electronics ============================= -- Kernelnewbies: Help each other learn about the Linux kernel. Archive: http://mail.nl.linux.org/kernelnewbies/ FAQ: http://kernelnewbies.org/faq/
