Messages in this thread |  | | From | Michael Schroeder <> | Date | Sun, 16 Sep 2001 13:32:06 GMT | Subject | Bug in console driver? |
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Hi!
I suppose there is a bug in the 2.4-kernel console driver (../drivers/char/console.c).
It seems that (if there is a slow video device) this driver disables the handling of interrupts while writing or switching the consoles.
Symptoms:
If you use the VESA framebuffer, switching to another console prevents updating the internal kernel clock (jiffies, xtime) for a short time. This effect can grow up to some seconds:
Load the GNU Midnight Commander (mc) and synchronize kernel clock and hardware clock with the command 'hwclock --hctosys'.
Then you can see the the difference with 'hwclock && date'.
# hwclock && date Sun Sep 16 10:31:33 2001 -0,154753 ... Sun Sep 10 10:31:32 CEST 2001
Now hold down the keys <Ctrl+o> for a some seconds. (This switches the window of the Midnight Commander on/off many times)
If you now compare the clocks you yield a difference of some seconds:
# hwclock && date Sun Sep 16 10:33:17 2001 -0,456384 ... Sun Sep 16 10:33:12 CEST 2001
5 seconds - I think this is a bug.
My system:
Intel Pentium II, 512 MB RAM NVIdia Riva TNT2 M64 with 32 MB Kernel 2.4.4 and 2.4.7 SuSE Linux 7.2 VESA Framebuffer
Greetings
Michael
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