There are certainly places the documentation could do better and this is clearly one of them. The simply answer is I’m reporting the numbers found in /proc/stat and don’t really know. I’m sure the real answer would come from reading the source but that’s not something I’m up for doing. Perhaps some time with google will help and if you do get a more precise answer and let me know I’ll update the docs.
Btw – 20K doesn’t sound all that high to me, as I’ve seen spikes in the 200K on busy systems with that many cores. -mark On Tue, Mar 26, 2013 at 3:19 PM, B.B. <[email protected]> wrote: > I'm using collectl to collect context switching rates in summary mode on a > 24 core machine (12 physical + hyper-threading). It reported high numbers of > context switches (20k+ spikes). > > My question is : What kind of context switches does collectl measure? Is it > user space to kernel space context switches, i.e. when making system calls > or multiple threads contending on one core? > > I could not find this information in the documentation. The tool > documentation only says : Total number of context switches/sec. Shall I > assume its measuring aggregate of user and kernel space context switches? > Appreciate any help. > > > Thanks, > Bhaskar > > Principal Software Engineer > http://www.SpaceCurve.com > > > ------------------------------------------------------------------------------ > Own the Future-Intel® Level Up Game Demo Contest 2013 > Rise to greatness in Intel's independent game demo contest. > Compete for recognition, cash, and the chance to get your game > on Steam. $5K grand prize plus 10 genre and skill prizes. > Submit your demo by 6/6/13. http://p.sf.net/sfu/intel_levelupd2d > _______________________________________________ > Collectl-interest mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/collectl-interest > ------------------------------------------------------------------------------ Own the Future-Intel® Level Up Game Demo Contest 2013 Rise to greatness in Intel's independent game demo contest. Compete for recognition, cash, and the chance to get your game on Steam. $5K grand prize plus 10 genre and skill prizes. Submit your demo by 6/6/13. http://p.sf.net/sfu/intel_levelupd2d _______________________________________________ Collectl-interest mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/collectl-interest
