Date: Sun, 10 Mar 2013 20:26:03 -0200 From: Jan Beich <jbeich@tormail.org> To: Jilles Tjoelker <jilles@stack.nl> Cc: Davide Italiano <davide@FreeBSD.org>, "Hartmann, O." <ohartman@zedat.fu-berlin.de>, FreeBSD Current <freebsd-current@freebsd.org>, Dimitry Andric <dim@FreeBSD.org> Subject: Re: r247839: broken pipe - for top, sudo and ports Message-ID: <1UEoh3-000Ly7-Mf@internal.tormail.org> References: <5135B7E1.3050002@zedat.fu-berlin.de> <5135BBD9.9090009@FreeBSD.org> <51364914.2010104@zedat.fu-berlin.de> <51364E8D.5020608@zedat.fu-berlin.de> <20130306212408.GA15814@stack.nl> <1UDUQ3-0009HU-83@internal.tormail.org> <20130310212256.GD94667@stack.nl>
next in thread | previous in thread | raw e-mail | index | archive | help
Jilles Tjoelker <jilles@stack.nl> writes:
> On Thu, Mar 07, 2013 at 04:54:01AM -0100, Jan Beich wrote:
>
>> Jilles Tjoelker <jilles@stack.nl> writes:
>
>> > On Tue, Mar 05, 2013 at 08:59:09PM +0100, Hartmann, O. wrote:
>
>> >> A "truss top" reveals this, is this of help?
>
>> >> [...]
>> >> stat("/etc/nsswitch.conf",{ mode=-rw-r--r--
>> >> ,inode=162310,size=1007,blksize=32768 }) = 0 (0x0)
>> >> stat("/etc/nsswitch.conf",{ mode=-rw-r--r--
>> >> ,inode=162310,size=1007,blksize=32768 }) = 0 (0x0)
>> >> stat("/etc/nsswitch.conf",{ mode=-rw-r--r--
>> >> ,inode=162310,size=1007,blksize=32768 }) = 0 (0x0)
>> >> stat("/etc/nsswitch.conf",{ mode=-rw-r--r--
>> >> ,inode=162310,size=1007,blksize=32768 }) = 0 (0x0)
>> >> stat("/etc/nsswitch.conf",{ mode=-rw-r--r--
>> >> ,inode=162310,size=1007,blksize=32768 }) = 0 (0x0)
>> >> socket(PF_LOCAL,SOCK_STREAM,0) = 4 (0x4)
>> >> connect(4,{ AF_UNIX "/var/run/nscd" },15) = 0 (0x0)
>> >> fcntl(4,F_SETFL,O_NONBLOCK) = 0 (0x0)
>> >> kqueue(0x80183b000,0x80122fc58,0x10,0x80062b308,0x80183b010,0x2)
>> >> = 5 (0x5)
>> >> kevent(5,{0x4,EVFILT_WRITE,EV_ADD,0,0x0,0x0},1,0x0,0,0x0) = 0 (0x0)
>> >> kqueue(0x5,0x7fffffffd2e0,0x1,0x0,0x0,0x0) = 6 (0x6)
>> >> kevent(6,{0x4,EVFILT_READ,EV_ADD,0,0x0,0x0},1,0x0,0,0x0) = 0 (0x0)
>> >> kevent(5,{0x4,EVFILT_WRITE,EV_ADD,1,0x4,0x0},1,0x0,0,0x0) = 0 (0x0)
>> >> kevent(5,0x0,0,{0x4,EVFILT_WRITE,EV_EOF,0,0x2000,0x0},1,0x0) = 1 (0x1)
>> >> sendmsg(0x4,0x7fffffffd290,0x0,0x1,0x1,0x0) ERR#32 'Broken pipe'
>> >> SIGNAL 13 (SIGPIPE)
>> >> process exit, rval = 0
>
>> > Apparently there is a bug that causes nscd to close the connection
>> > immediately but even then it is wrong that this terminates the calling
>> > program with SIGPIPE.
>
>> > The below patch prevents the SIGPIPE but cannot revive the connection to
>> > nscd. This may cause numeric UIDs in top or increase the load on the
>> > directory server. It is compile tested only.
>> [...]
>
>> The patch seems to fix the issue in a world after r247804. I don't see
>> numeric UIDs in top but without the patch top crashes with SIGPIPE a lot
>> less frequently than sudo or make install (in base/ports) for me.
>
>> In my case shutting down nscd helped, too. Compared to stock
>> nsswitch.conf I only have "cache" added.
>
> Can you find what causes nscd to close the connection quickly, such as
> using ktrace?
# single user mode
$ ktrace -p $(pgrep nscd); top -b; ktrace -c; kdump
71 nscd GIO fd 5 wrote 0 bytes
""
71 nscd GIO fd 5 read 32 bytes
0x0000 0400 0000 0000 0000 ffff 1000 0000 0000 0100 |..................|
0x0012 0000 0000 0000 0000 0000 0000 0000 |..............|
71 nscd RET kevent 1
71 nscd CALL accept(0x4,0,0)
71 nscd RET accept 6
71 nscd CALL getsockopt(0x6,0,0x1,0x7fffff9fce28,0x7fffff9fce24)
71 nscd RET getsockopt 0
71 nscd CALL kevent(0x5,0x7fffff9fcf00,0x2,0,0,0x7fffff9fcf50)
71 nscd GIO fd 5 wrote 64 bytes
0x0000 0600 0000 0000 0000 f9ff 1100 0000 0000 401f |................@.|
0x0012 0000 401f 0000 40e6 4002 0800 0000 0600 0000 |..@...@.@.........|
0x0024 0000 0000 ffff 1100 0100 0000 0400 0000 0000 |..................|
0x0036 0000 40e6 4002 0800 0000 |..@.@.....|
71 nscd GIO fd 5 read 0 bytes
""
71 nscd RET kevent 0
71 nscd CALL kevent(0x5,0x7fffff9fcec0,0x1,0,0,0x7fffff9fcee0)
71 nscd GIO fd 5 wrote 32 bytes
0x0000 0400 0000 0000 0000 ffff 1100 0000 0000 0000 |..................|
0x0012 0000 0000 0000 0000 0000 0000 0000 |..............|
71 nscd GIO fd 5 read 0 bytes
""
71 nscd RET kevent 0
71 nscd CALL kevent(0x5,0,0,0x7fffff9fcec0,0x1,0)
71 nscd GIO fd 5 wrote 0 bytes
""
71 nscd GIO fd 5 read 32 bytes
0x0000 0600 0000 0000 0000 f9ff 3000 0000 0000 0100 |..........0.......|
0x0012 0000 0000 0000 40e6 4002 0800 0000 |......@.@.....|
71 nscd RET kevent 1
71 nscd CALL close(0x6)
71 nscd RET close 0
71 nscd CALL kevent(0x5,0,0,0x7fffff9fcec0,0x1,0)
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?1UEoh3-000Ly7-Mf>