Public bug reported:

Binary package hint: linux-image-2.6.24-19-generic

Upon switching from Dapper to Hardy, I noticed one of my systems kept
getting serial timeouts.  Upon further investigation, it seems that
there is a serial deadlock issue in kernels < 2.6.27, where machines
with multiple processors and multiple serial devices can call the serial
interrupt handler at the same time and become deadlocked.  This was
fixed in 2.6.27 with 4 lines of code.  I have created a patch with the
same four line based on the linux-source-2.6.24.tbz (from installing
linux-source package), and I have tested it with many serial deives
talking at once.  My problems go away.  Given that this is such a
fundamental bug (deadlock in interrupt handlers), I feel it is necessary
to apply this to the LTS kernels in Hardy.

The original discussion of this bug and the patch (by the usual kernel 
programmers) is at:
http://kerneltrap.org/mailarchive/linux-kernel/2008/7/1/2313364

Note, that the final fix in 2.6.27 keeps the lock and unlock lines as
they were (the original discussion at the thread above changed them).
My patch does not change them (as in the final 2.6.27 patch for this
problem).

** Affects: linux (Ubuntu)
     Importance: Undecided
         Status: New

-- 
serial deadlock with SMP
https://bugs.launchpad.net/bugs/280821
You received this bug notification because you are a member of Ubuntu
Bugs, which is subscribed to Ubuntu.

-- 
ubuntu-bugs mailing list
[email protected]
https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs

Reply via email to