Hi, Its unlikely to used jiffies value to calculate time period spent in ISR.In all existing ISR it will give you zero.As processor speed is too much and ISR will end up in few microseconds at the most. I will suggest you to use time stamp counter and make appropriate calculateion using difference in TSC value and your processor speed multiplication to them. For example each NOP instruction will take 1 machine cycle and gives you 1 as difference in tsc. You can get this info on google. But still if you want some info on how to calculate it i will provide you example code. Prasanna --- "Usman S. Ansari" <uansari@xxxxxxxxx> wrote: > Checkout > <http://www.opersys.com/ltt/news.html>http://www.opersys.com/ltt/news.html > > Mandeep Sandhu wrote: > > >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 > >>> > > -- > http://www.beconvinced.com > > > -- > Kernelnewbies: Help each other learn about the Linux > kernel. > Archive: > http://mail.nl.linux.org/kernelnewbies/ > FAQ: http://kernelnewbies.org/faq/ > > __________________________________ Do you Yahoo!? The all-new My Yahoo! - What will yours do? http://my.yahoo.com -- Kernelnewbies: Help each other learn about the Linux kernel. Archive: http://mail.nl.linux.org/kernelnewbies/ FAQ: http://kernelnewbies.org/faq/
