On 20/10/2007, Jeff Garzik <[EMAIL PROTECTED]> wrote: > Chuck Ebbert wrote: > > On 10/19/2007 05:39 PM, Jeff Garzik wrote: > >> On my main devel box, vanilla 2.6.23 on x86-64/Fedora-7, I'm seeing a > >> certain behavior at least once a day. I'll start a kernel build (make > >> -sj5 on this box), and it will "hang" in the following way: > >> > > > > Can you try to strace the hanging task? > > Well, to the system it's running, so that doesn't do much of anything... > > > > > 8482 pts/0 S+ 0:00 \_ /bin/sh > > /garz/repo/misc-2.6/scripts/hdrcheck.sh /garz/repo/misc-2.6/usr/include > > /garz/repo/misc-2.6/usr/include/linux/kernelcapi.h > > /garz/repo/misc-2.6/usr/include/linux/.check.kernelcapi.h > > 8484 pts/0 R+ 3:10 \_ grep ^[ \t]*#[ > > \t]*include[ \t]*< /garz/repo/misc-2.6/usr/include/linux/kernelcapi.h > > 8486 pts/0 S+ 0:00 \_ cut -f2 -d< > > 8487 pts/0 S+ 0:00 \_ cut -f1 -d> > > 8488 pts/0 S+ 0:00 \_ egrep ^linux|^asm > > [EMAIL PROTECTED] misc-2.6]$ strace -p8484 > > Process 8484 attached - interrupt to quit > [sits there, chewing up CPU grepping a 47-line header file]
I think, the following information would be helpful : (1) # cat /proc/PID/stat ; sleep 5; cat /proc/PID/stat as we could know : - whether utime or/and stime keeps increasing ; - one of the fields is actually 'eip' ... so we could, hopefully, more or less precisely localize the area of the code where it's looping. (do_task_stat() in fs/proc/array.c) (2) # cat /proc/sched_debug; and # cat /proc/PID/sched (if your kernel has CONFIG_SCHED_DEBUG=y) (3) is anything else able to run on this CPU (as I understand it's SMP) or the task does completely locks it up. again, one of the fields of /proc/PID/stat is the CPU# on which the task is currently active. Let's start a buzy-loop task on this cpu and see wheather it's able to make any progress (TIME counter in 'ps') # taskset -c THIS_CPU some_busy_looping_prog TIA, -- Best regards, Dmitry Adamushko - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
