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What happens when interrupts are disabled?
The device responsible for an interrupt will not get any response while waiting – which is kind of a response anyway. If it can’t wait, it might enter some error state that the CPU will see when it eventually comes around. You will only get the interrupts you have explicitly enabled, so there should be no surprises.
How does an interrupt can be enabled?
Enabling and Disabling an Interrupt The interrupts must be enabled using software in order for the microcontroller to respond to those interrupts. IE (interrupt enable) register is responsible for enabling and disabling the interrupt. IE is a bitaddressable register.
How can we disable interrupt?
When entering an inteerupt handler, we first “disable interrupts” on that cpu(using something like the cli instruction on x86). During the time that interrupts are disabled, assume say the user pressed the letter ‘a’ on the keyboard that would usually cause an interrupt.
What does it mean when interrupts are disabled?
During the time that interrupts are disabled, assume say the user pressed the letter ‘a’ on the keyboard that would usually cause an interrupt. But since interrupts are disabled, does that mean that: the interrupt will be handled by the os but delayed, until interrupts are enabled again.
What is the difference between disarming and interrupting a device?
Conversely, to disarm a device means to shut off or disconnect the hardware trigger from the interrupts. Each potential interrupting trigger has a separate arm bit. One arms a trigger if one is interested in interrupts from this source. Conversely, one disarms a trigger if one is not interested in interrupts from this source.
How can interinterrupt latency be reduced?
Interrupt latency is reduced by special optimization, including late arrival interrupt acceptance and tail-chain interrupt entry. Some of the multicycle operations, including Load-Multiple (LDM), Store-Multiple (STM), PUSH, and POP, are now interruptible.
What happens when you disable interrupts in Linux?
Disabling interrupts effectively turns off the preemptive scheduling ability of your system. Doing this may adversely affect system performance. The more time spent in a critical section with interrupts turned off, the greater the degradation in system latency.