can another ISR preempt the current executing ISR! during execution of ISR's are'nt the interrupts disabled?
do ISR's also have priority associated with them???
i think b4 executing an ISR the kernel calls "preempt-disable" (not very sure though....)???
- /dev/mandeep
mandeep sandhu wrote:
hi all, i've heard that the linux kernel is preemptive from 2.5 onwards.... so can an ISR be preempted by the kernel. as i understand an ISR doest not have a process context, so then what can preempt it????
Yes you're right. An ISR has no process context. But an ISR can be interrupted by some code lika for example another ISR. Interrupts can be nested in Linux (even in 2.4). And in 2.5 and 2.6, ISR can be preempted by a thread or anything else which has a higher priority.
-- Kernelnewbies: Help each other learn about the Linux kernel. Archive: http://mail.nl.linux.org/kernelnewbies/ FAQ: http://kernelnewbies.org/faq/
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-- Kernelnewbies: Help each other learn about the Linux kernel. Archive: http://mail.nl.linux.org/kernelnewbies/ FAQ: http://kernelnewbies.org/faq/
