hi,
we have lots of pppd processes in tty_ioctl state:
[root@pptp ~]# cat /proc/633/wchantty_ioctl
strace says:[root@pptp ~]# strace -p 633Process 633 attached - interrupt to quitioctl(8, TIOCSETD <unfinished ...>Process 633 detached
GDB says that they are inside of tty_disestablish_ppp:
(gdb) bt#0 0x00fec402 in __kernel_vsyscall ()#1 0x0056f8d9 in ioctl () from /lib/i686/nosegneg/libc.so.6#2 0x80025034 in tty_disestablish_ppp () from /usr/sbin/pppd#3 0x8001dbc6 in link_terminated () from /usr/sbin/pppd#4 0x8000f4ef in ?? () from /usr/sbin/pppd#5 0x8000d2f8 in fsm_input () from /usr/sbin/pppd#6 0x8000f1cd in ?? () from /usr/sbin/pppd#7 0x8000c3c2 in main () from /usr/sbin/pppd(gdb) quit
So, the code in question is:
/* * Restore the previous line discipline */ if (ioctl(tty_fd, TIOCSETD, &tty_disc) < 0) { if ( ! ok_error (errno)) error("ioctl(TIOCSETD, N_TTY): %m (line %d)", __LINE__); }
We are running Fedora Core 8:
[root@pptp ~]# uname -aLinux pptp 2.6.21-2950.fc8xen #1 SMP Tue Oct 23 12:24:34 EDT 2007 i686i686 i386 GNU/Linux
which uses the most recent pppd:
[root@pptp ~]# rpm -qi pppName : ppp Relocations: (not relocatable)Version : 2.4.4 Vendor: (none)Release : 3 Build Date: Tue 08 Apr2008 12:57:11 PM MSD
This bug seems to be rather old. Here is the extensive analysis from 2005:
http://lkml.org/lkml/2005/2/15/244
There are also some other similar reports scattered around the internet.
Could something be done about it? Maybe some work-around in pppditself? We have 50+ such processes on our machine, and we do notunderstand how it will affect our performance.
Thank you,
-- Алексей Махоткинhttp://squadette.ru/��.n��������+%����;��w��{.n�����{���i�)�� jg��� �����ݢj����G���� ���j:+v���w�m������w�������h�����٥
