make buildkernel hang with SCHED_ULE

From: Adam Migus <adam_at_migus.org>
Date: Mon, 11 Aug 2003 10:44:55 -0400 (EDT)
Folks,
While doing some performance analysis (doing make -j5 buildkernel)
on a set of 14 kernels I've hit one using the SCHED_ULE scheduler
that hangs.   It happens every time but not necessarily in the same
place in the make.

When it happens the processes involved in the make are hopping in
and out of the "select," "RUN," etc. states but don't go anywhere
and the system is otherwise responsive, ie. you can login, run "ps,"
"top," etc.

The hardware is a dual Xeon box.  The kernel is SMP w/ SCHED_ULE
instead of SCHED_4BSD, the options required for diskless and the
following two options:

options         CPU_FASTER_5X86_FPU
options         CPU_UPGRADE_HW_CACHE

I've attached the kernel configuration, the output of "dmesg," "ps
-axuww," and "sysctl -A" prior to the start of the test as well as
the output of "make" up to the time it hung.

I don't have any experience debugging scheduler problems but if
someone wants to tell me what to do I'd be happy to try.

--
Adam - Migus Dot Org (http://www.migus.org)
Received on Mon Aug 11 2003 - 05:45:02 UTC

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