lkml.org 
[lkml]   [2001]   [Jun]   [21]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: Is it useful to support user level drivers
> There is no such thing as a "user mode" interrupt service routine.
> There never was one, and there will never be one on any machine
> that fetches instructions from memory for execution. [...]

If memory does not deceive me, SunLab Spring processed interrupts
in user space. I do not remember for sure, but I think QNX did, too.
User mode interrupt handlers are perfectly doable, provided that the
hardware allows to mask interrupts selectively.

Large part of the post that I quoted was spent on spitting
in the general direction of clueless programmers; indeed,
I observe that perhaps 90% of requests for user mode interrupt
processing come from the same people who would like to write
Linux kernel mode code in C++ (total retards, in other words).

It does not mean, however, that there are not justified cases
for user-mode interrupt handlers, especially outside of Linux.
Some OSes are even written in C++ and Java, and run just fine
on a machine that fetches instructions from memory.

-- Pete
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2005-03-22 12:55    [from the cache]
©2003-2011 Jasper Spaans