> x86 does indeed have hardware interrupt priorities > (check vol.3 of the arch manual > from Intel) but they are not used by linux afaik, > notwithstanding "irqtune". Intel IA-32 arch. manual only specifies the priority in which interrupts are serviced in case of multiple simultaneous interrupts. x86 doesn't provide a direct way to selectively block some interrupts. (at least I didn't find any reference in the manual). So Linux or any other OS on x86 has to simulate interrupt priority levels in software. I guess the SCO Unixware implementation is to use a global variable for storing the priority level, and check that in each interrupt handler. Ravi. __________________________________________________ Do You Yahoo!? Check out Yahoo! Shopping and Yahoo! Auctions for all of your unique holiday gifts! Buy at http://shopping.yahoo.com or bid at http://auctions.yahoo.com -- Kernelnewbies: Help each other learn about the Linux kernel. Archive: http://mail.nl.linux.org/kernelnewbies/ IRC Channel: irc.openprojects.net / #kernelnewbies Web Page: http://www.kernelnewbies.org/
