On Mon, 2005-02-21 at 10:32 -0800, Om wrote: > On Mon, Feb 21, 2005 at 04:16:38PM +0530, Mandeep Sandhu hit keys to express the following: > > Hi all, > > > > Can someone suggest a reliable way of calculating the amount of time > > spent inside an ISR? > > > > one way i figured was to store the jiffies value on entering and exiting > > the ISR and subtract these to get the time spent inside a drivers ISR. > Will that work? Not sure here. I think only the line on which the interrupt occurred is masked....i'm not too sure whether the timer interrupt is masked as well. your thoughts........? rdtsc() would be processor specific. is there any other way by which I one can figure out the time spent? Thanks anyways, -mandeep > jiffies are updated only when a timer interrupt (0) occurs. If you have called > sti() there will not be any timer interrupt and consequently no jiffies > increment. May be a better way is to use rdtsc() (for reading time stamp counter > ) in the beginning and at the end and find out the milli/micro seconds spent. > HTH, > Om. > -- Kernelnewbies: Help each other learn about the Linux kernel. Archive: http://mail.nl.linux.org/kernelnewbies/ FAQ: http://kernelnewbies.org/faq/
