ubuntu-x-swat team mailing list archive

[Tom Jaeger <ThJaeger@xxxxxxxxx>]

Public bug reported:

On my system, Xorg takes up 100% of (one of the) CPUs after startup.
The problem goes away once the X server is restarted.  This happens both
with the xserver from the archive and the latest 1.7 snapshot.  This
might be a race related to the fact that ubuntu is installed on an SSD.
It seems to be the same problem that is discussed in this ubuntuforums
thread:

http://swiss.ubuntuforums.org/showthread.php?t=1272691

Here is what I could find out about the problem:

strace reports repeated (failing) calls to

ioctl(5, TCFLSH, 0x2)                   = -1 EIO (Input/output error)

where fd 5 is /dev/tty7.  This translates to a tcflush call in
drain_console().  Backtrace:

Breakpoint 6, drain_console (fd=5, closure=0x0) at ../../../../../hw/xfree86/os-support/linux/lnx_init.c:89
89      ../../../../../hw/xfree86/os-support/linux/lnx_init.c: No such file or directory.
        in ../../../../../hw/xfree86/os-support/linux/lnx_init.c
(gdb) bt
#0  drain_console (fd=5, closure=0x0) at ../../../../../hw/xfree86/os-support/linux/lnx_init.c:89
#1  0x000000000046ecd1 in xf86Wakeup (blockData=<value optimized out>, err=<value optimized out>, pReadmask=<value optimized out>)
    at ../../../../hw/xfree86/common/xf86Events.c:285
#2  0x0000000000443c7b in WakeupHandler (result=7, pReadmask=0x7d8440) at ../../dix/dixutils.c:413
#3  0x00000000004609d5 in WaitForSomething (pClientsReady=<value optimized out>) at ../../os/WaitFor.c:232
#4  0x0000000000440ef2 in Dispatch () at ../../dix/dispatch.c:381
#5  0x00000000004265fc in main (argc=9, argv=0x7d7228, envp=<value optimized out>) at ../../dix/main.c:285
o

So we have a fd in some kind of error state that causes select() to
always return right away.  I don't know enugh about how select() works
to identify the problem, though.

** Affects: xorg-server (Ubuntu)
     Importance: Undecided
         Status: New

-- 
[karmic] Xorg 100% CPU utilization after startup
https://bugs.launchpad.net/bugs/439138
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