[lkml]   [1999]   [Oct]   [21]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: raw memory & PCI bus access wrote:
> Hi all
> Say I have a driver that realizes a "virtual irq" (/dev/irq).

I think Pavel Machek may have already written something like this?

> User application waits for interrupts by calling select() for
> that device. Obviously such a driver doesn't need much of code.
> What a maximum latency between irq occurance and
> userapp reaction I should expect?

In modern machines it shouldn't be too bad -- but if you are concerned
about it, a better course may be to at least put your interrupt handler
in kernel space.

Another possibility is have your user space driver pass information to
/dev/irq, which tells the generic /dev/irq how to acknowledge
interrupts, read data into a buffer, and other simple operations like


To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to
Please read the FAQ at

 \ /
  Last update: 2005-03-22 13:54    [from the cache]
©2003-2014 Jasper Spaans. hosted at Digital Ocean