On Mon, 2013-04-01 at 19:27 +0530, Vineet Gupta wrote: > Hi, > > Any thoughts: I observe the same issue even with CONFIG_PREEMPT and > CONFIG_PREEMPT_COUNT > > -Vineet > > On 03/30/2013 06:05 PM, Vineet Gupta wrote: > > Hi, > > > > I've been stress testing ARC Linux 3.8 (same happens for 3.9-rc3 as well). > > The > > setup has 3 telnet sessions, each running find . -name "*" in a loop. > > The platform is a FPGA @ 80 MHz, running a single core ARC700 so kernel > > .config > > has !SMP and PREEMPT_NONE. > > > > After ~10 mins of run, I see that one of the telnet session gets stuck (and > > later > > the 2nd one as well), while system is still alive, 3rd telnet is running > > find merrily. > > > > [ARCLinux]$ ps > > .... > > 7 root 0:00 inetd > > 62 root 0:00 -/bin/sh > > 64 root 1:34 telnetd -i -l /bin/sh > > 65 root 0:00 /bin/sh > > 75 root 1:47 telnetd -i -l /bin/sh > > 76 root 0:00 /bin/sh > > 79 root 0:53 telnetd -i -l /bin/sh > > 80 root 0:00 /bin/sh > > 281 root 0:00 find / -name * <--- stuck > > 358 root 0:03 find / -name * <--- stuck > > 377 root 0:00 find / -name * > > 378 root 0:00 ps > > > > Hung find task is sitting in the schedule() call in n_tty_write() > > > > [ARCLinux]$ cat /proc/281/stack > > [<8065945e>] n_tty_write+0x23a/0x424 > > [<80655cd4>] tty_write+0x1ac/0x2d4 > > [<805976ba>] vfs_write+0x92/0x110 > > [<80597816>] sys_write+0x4e/0x88 > > [<8050e780>] ret_from_system_call+0x0/0x4
Likely the writer is stuck because the receive buffer is full and the reader is hung. What are the respective shells and telnetd doing? Regards, Peter Hurley PS - include the controlling tty column in your ps output :) -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
