The interruptions that occur as a result of the computer’s chronometer indicating a termination of the time interval assigned to a process (time slice), are they classified as synchronous or asynchronous interruptions? Answer Time interrupts, as hardware interrupts are considered as all hardware interrupts as asynchronous. Despite the fact that this can lead to confusion, let me explain: Synchronous interrupts
Tag: interrupt
tickless kernel , isolcpus,nohz_full,and rcu_nocbs
I have add “isolcpus=3 nohz_full=3 rcu_nocbs=3” in grub.conf in RedHat 7.1 , kernel: linux 3.10.0-229 kernel and according to http://www.breakage.org/2013/11/15/nohz_fullgodmode/ I also execute the following command : The box has only 4 cpu cores , I run the following shell : look like work perfect , only cpu0 Local timer interrupts has 2000 per 2 secs, the else cpu 1
Why is interrupt disabled between spin_lock and spin_unlock in Linux?
I was reading the implementation of Linux semaphores. Due to atomicity, signal and wait (up and down in the source code) use spin locks. Then I saw Linux disabled interrupt in spin_lock_irqsave and reenabled interrupt in spin_unlock. This confused me. In my opinion, there is really no point disabling interrupt within a critical section. For example, proc A (currently active)
How to run hrtimer handler in softirq context?
I have found this tutorial about hrtimer: http://www.ibm.com/developerworks/linux/library/l-timers-list/ I believe the way it uses will run the callback handler in hardirq context,right? But it also said “One interesting aspect is the ability to define the execution context of the callback function (such as in softirq or hardiirq context)” I have checked the hrtimer.h file but it’s really not that intuitive.