On Sat, Feb 14, 2009 at 05:22:06PM +0530, Sukanto Ghosh wrote: > Hi, > > I have made some changes to the memory management part of the kernel > as an experiment. Now when I boot into that kernel and start some > heavy processes (which cause paging), the kernel hangs. I can't even > type anything. > > I have gone through the 'paper on debugging kernel oops or hang' > (http://mail.nl.linux.org/kernelnewbies/2003-08/msg00347.html) > > In this paper Erik says that to get the stack trace we can type > 'Alt-SysRq-t' which prints the stack trace and when it's not possible > to type anything, then it's best to use serial port + console. he says > the config for lilo would be: console=ttyS0,9600 console=tty0 > > As I have grub I am using the following lines: > > default=0 > timeout=15 > title Fedora (2.6.27.4) > root (hd0,0) > kernel /boot/vmlinuz-2.6.27.4 ro root=/dev/sda1 > initrd /boot/initrd-2.6.27.4.img > serial --unit=0 --speed=9600 --word=8 --parity=no --stop=1 > terminal --dumb --timeout=10 serial console > > > > CONFIG_MAGIC_SYSRQ was enabled in my config file. > > My test kernel is running inside a Virtual machine (VM) (VMware), with > its serial port 0 redirected to a file. > VM OS: fedora Core 9 with modified kernel 2.6.27.4 > Host OS: ubuntu hardy 2.6.24.3 > > My problem is I am not getting any kind of output in the file to which > I redirected the serial port of the VM except a bunch of "Press any > key to continue .. " messages. > > should I be providing the 'alt-sysrq-t' input through the serial port, > if so, how ? > can i connect a host terminal to the serial port of the VM. > Vmware gives me three options about the serial port of the Virtual Machine > i) connect it to physical port of the host, ii) connect to a named > pipe and, iii)connect it to a file in the host. > > Please help ... > > > -- > Regards, > Sukanto Ghosh > > -- > To unsubscribe from this list: send an email with > "unsubscribe kernelnewbies" to ecartis@xxxxxxxxxxxx > Please read the FAQ at http://kernelnewbies.org/FAQ > Hi, What I would suggest first is to enable the nmi watchdog to detect the hardlockups, see Documentation/nmi_watchdog.txt And enabling earlyprintk through the serial port, and keep it when the console is set, this way you will see the printk messages through the virtual serial line. As a parameter: earlyprintk=serial,ttyS0,115200,keep 9600 is too slow. -- To unsubscribe from this list: send an email with "unsubscribe kernelnewbies" to ecartis@xxxxxxxxxxxx Please read the FAQ at http://kernelnewbies.org/FAQ
