Description of problem: When I boot up I get a hang with Kudzu. Version-Release number of selected component (if applicable): kernel-2.6.17-1.2187_FC5.src.rpm How reproducible: I've seen this on 3 systems. Steps to Reproduce: 1. Boot, and it hangs on kudzu. Additional info: I've seen this on 3 different systems. On 2 systems I get a hang when kudzu is run but on the other system I get a reboot when kudzu is run. On the systems that lock up it's a complete lock. Numlock doesn't work. SYSREQ doesn't work. I don't get a watchdog timer dump. It seems to be related to readahead_early. If I chkconfig readahead_early off I don't get a hang. If I chkconfig kudzu off and then run it after the system has booted I get a hang. If I modify the kudzu service to run kudzu under strace then it doesn't hang. If I modify the kudzu service to have a sleep before runing kudzu then it doesn't hang because readahead_early completes. My co-workers report that with the 2.6.16-1.2080_FC5 if they manually type numa=off at the command line then it doesn't hang but if they use grub to do that then it does hang. They say that if they upgrade to 2.6.17-1.2187_FC5 and use numa=off then it doesn't hang. I've looked through the readahead code and that looks straight forward. I've started looking through the kudzu code but I haven't got very far on that yet.
Sorry, I meant to post a bunch more information but all 3 systems have been taken away until Monday... :/
I'm reassigning this bug to kudzu. The bug happens in ddc probing. What I did is in one terminal I do: cat /dev/zero > /tmp/foo In the other terminal I modified kudzu to run: for (i = 0; i < 500; i++) { get_edid_supported(); get_edid_supported() calls: iopl(3); ioperm(0, 0x400, 1); if (f->interrupt(0x10, ®s) == 0) { return 0; } f->interrupt() sometimes locks the system. I'm using AMD64 so it's using the x86emu stuff. f->interrupt() calls x86emu_LRMI_int() from thunk.c. There's quite a bit of code in the x86emu stuff that messes with interrupts. I'm testing with a one cpu dual core opteron box. In FC6, kudzu doesn't do any ddc probing...
Created attachment 138102 [details] dmesg for reference
This is fixed in the FC6 development tree.