Hi, I was reading LKD by Robert Love. I got the following idea from the book. Correct me if I am worng I was checking through source code and I found that on every timer interrupt, through sched/fair.c we are raising the SCHED_SOFTIRQ(). I was checking the relation between SCHED_SOFTIRQ and actual __schedule() function. My assumption: schedule() function is the function which selects the processes which are ready to run in run queue. schedule() function is called in every timer tick. What I was thinking is that schedule() will be called as part of handling SCHED_SOFTIRQ() . But in source code, SCHED_SOFTIRQ is handled through run_rebalance_domain() function (sched/fair.c) . I am unable to trace __schedule() from this function. Am I missing anything or my assumptions are wrong? -- Regards, Sreejith