Stephen, On 22 Feb, 23:10, "Stephen Oberholtzer" <[EMAIL PROTECTED]> wrote: > First off: I'm not subscribed to the list (I don't think I could > handle the volume), so please make sure you CC me if you reply. > > I run an application on one of my machines; it often hangs, with the > process stuck D state. When this happens, the process sticks around > until I reboot the machine. > > I have tried the following to start diagnosing the problem: > > * Running 'ps -axl' shows "-" in the wchan column. > * The contents of /proc/pid/wchan say "_stext". > * 'strace -p pid' says "Process pid attached - interrupt to quit" and > stops responding. Sending SIGINT and SIGTERM have no effect on the > strace process, although kill -11 (SIGSEGV, my personal favorite) does > work. > > This is very confusing. I would greatly appreciate it if someone > could tell me how a process can enter D state without being in a > syscall, and what I can do to start tracking down the cause.
wchan shows where the process is sleeping - probably a kernel mutex or lock here. This doesn't help much, but the stack signature will. Enable and use the sys-request mechanism (via terminal, keyboard or serial) eg sysrq-T to dump the stack frames of all processes, including this. Unsurprisingly, it's documented in the kernel Documentation directory. > (By the way: This is on amd64, 2.6.23. I'm updating to 2.6.24.2 right > now, on the off chance that whatever was causing the problem has been > fixed.) Daniel -- Daniel J Blueman -- 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/
