LKML Archive on lore.kernel.org
help / color / mirror / Atom feed
* Soft and Hard Interrupts
@ 2004-05-26 14:52 Andreas Hess
0 siblings, 0 replies; only message in thread
From: Andreas Hess @ 2004-05-26 14:52 UTC (permalink / raw)
I have difficulties in understanding the interplay between hard and soft
interrupts. Perhaps things get clearer with the following example:
1.) a packet is arriving at a NIC and triggers the execution of a hardware
2.) the do_irq() routine is called
3.) the according interrupt service routine (ISR) is executed (which triggers
a soft interrupt)
4.) the kernel terminates the do_irq() routine and checks if there is a soft
interrupt waiting to be processed
5.) the soft interrupt is processed
The higher the arrival rate of packets, the higher the amount of interrupts to
be processed. In order to prevent the system from permanently processing
interrupts --- in case that a certain threshold value is reached --- the
ksoftirqd daemon takes over the responsibility for the software interrupt
handling. Then software interrupts are processed in the event that the
ksoftirqd is scheduled and running.
Is this so far correct? If yes, I wonder how the threshold value, the point at
which the ksoftirqd gets into charge, is defined?
Please 'CC' me as I am not subscribed to the list.
^ permalink raw reply [flat|nested] only message in thread
only message in thread, other threads:[~2004-05-26 15:01 UTC | newest]
Thread overview: (only message) (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2004-05-26 14:52 Soft and Hard Interrupts Andreas Hess
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).