Linux 1.3.13 & "Idle Task may not sleep" error

Mark Crichton (macricht@indyunix.iupui.edu)
Thu, 27 Jul 1995 16:51:35 -0500 (EST)

Hello fellow linux-kernel hackers!
I've recently upgraded to Linux 1.3.13 from Linux 1.3.11 and I've
noticed something new during my boot sequence...this "idle task may not sleep"
message. I've noticed that it is involved with Linus' scheduler patches that
were posted here a while back.
What I want to know is:
1.) With the appearance of this message, is it time for me to panic? (TTTT, I
don't really understand the inner workings of that section of the kernel...)
2.) How can I trace down the code responsible for the routine. ( I feel
perfectly comfortable ripping up the code if I had some idea in which direction
I should head)

My system config is: Linux 1.3.13 w/SLIP, the new PPP code added, PS2 mouse,
the lp driver, new IDE driver (and that's about it). Here's a snippet of my
boot logs (FWIW)

Jul 27 11:12:09 magic syslogd: restart
Jul 27 11:12:10 magic kernel: Kernel logging (proc) started.
Jul 27 11:12:10 magic kernel: Console: 16 point font, 400 scans
Jul 27 11:12:10 magic kernel: Console: colour VGA+ 80x25, 1 virtual console (max 63)
Jul 27 11:12:10 magic kernel: Calibrating delay loop.. ok - 16.61 BogoMips
Jul 27 11:12:10 magic kernel: Serial driver version 4.11 with no serial options
enabled
Jul 27 11:12:10 magic kernel: tty00 at 0x03f8 (irq = 4) is a 16550A
Jul 27 11:12:10 magic kernel: tty01 at 0x02f8 (irq = 3) is a 16550A
Jul 27 11:12:10 magic kernel: tty02 at 0x03e8 (irq = 4) is a 16550A
Jul 27 11:12:10 magic kernel: lp0 at 0x03bc, (polling)
Jul 27 11:12:10 magic kernel: PS/2 auxiliary pointing device detected -- driver
installed.
Jul 27 11:12:10 magic kernel: idle task may not sleep
Jul 27 11:12:10 magic kernel: idle task may not sleep
Jul 27 11:12:10 magic kernel: hda: WDC AC2420H, 405MB w/128KB Cache, CHS=989/15/56, MaxMult=16

TIA,
Mark Crichton