Re: DTrace: Sending ^C while running script produces no output
on 03/12/2010 07:20 Brandon Gooch said the following:
I've been tinkering with DTrace a bit, and I've notice something
peculiar on each system I've tried it on.
Sending ^C from the keyboard in the terminal (console, XTerm, Konsole)
produces no output [1].
Can you ktrace the dtrace process?
I wonder, could it be that SIGINT from ^C is somehow delivered twice?..
For example, while trying out a one-liner (from
http://www.brendangregg.com/DTrace/dtrace_oneliners.txt):
bran...@d820:~$ sudo dtrace -n 'syscall:::entry { @num[execname] = count(); }'
dtrace: description 'syscall:::entry ' matched 514 probes
^C
BTW, sudo might play a role here... Just a thought.
bran...@d820:~$ (12-02
23:11)
If I instead, from another terminal, use pkill to quit or terminate
the process, I get output:
bran...@d820:~$ sudo dtrace -n 'syscall:::entry { @num[execname] = count();
}';
dtrace: description 'syscall:::entry ' matched 514 probes
akonadi_control 4
akonadiserver 5
syslogd 6
sendmail 8
akonadi_ical_resour 12
akonadi_maildir_res 12
akonadi_nepomuk_con 12
akonadi_vcard_resou 12
kuiserver12
akonadi_maildispatc 14
korgac 14
virtuoso-t 15
dbus-daemon 17
mysqld 18
hald 24
knotify4 27
akonadi_contacts_re 36
nepomukservicestub 70
pkill70
powerd 72
dtrace 101
zsh 111
sudo495
kwin 2812
firefox-bin3175
kdeinit4 11044
Xorg 39588
bran...@d820:~$ (12-02
23:14)
I also want to add that I've tried this with a variety of shells on
both 8.2-PRERELEASE and HEAD systems, i386 and amd64, built with GCC
and nearly GENERIC kernels in order to try to eliminate the cause.
I feel as though this has something to do with file descriptors being
closed too soon when handling the signal or something of that nature.
It's also been suggested that this could be a bug in libdtrace, but I
haven't the knowledge (or skill) to try and pinpoint the cause myself.
Is there anyone here that may be able to provide feedback or debugging
suggestions?
Thanks!
-Brandon
[1] This isn't always the case, only like 99.99% of the time.
Sometimes I do get output, but usually it's just snippets, and
sometimes random characters!
--
Andriy Gapon
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Re: DTrace: Sending ^C while running script produces no output
On Sat, Dec 4, 2010 at 2:32 PM, Andriy Gapon a...@freebsd.org wrote:
on 03/12/2010 07:20 Brandon Gooch said the following:
I've been tinkering with DTrace a bit, and I've notice something
peculiar on each system I've tried it on.
Sending ^C from the keyboard in the terminal (console, XTerm, Konsole)
produces no output [1].
Can you ktrace the dtrace process?
I wonder, could it be that SIGINT from ^C is somehow delivered twice?..
I'll give it a shot in just a bit.
For example, while trying out a one-liner (from
http://www.brendangregg.com/DTrace/dtrace_oneliners.txt):
bran...@d820:~$ sudo dtrace -n 'syscall:::entry { @num[execname] = count();
}'
dtrace: description 'syscall:::entry ' matched 514 probes
^C
BTW, sudo might play a role here... Just a thought.
I could see that for sure. I can't believe I hadn't thought of that
right off the bat, but then again I tested while logged in as root
from the console -- I think :/
Human memory is unreliable y'know...
-Brandon
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Re: DTrace: Sending ^C while running script produces no output
On Sat, Dec 4, 2010 at 3:27 PM, Brandon Gooch
jamesbrandongo...@gmail.com wrote:
On Sat, Dec 4, 2010 at 2:32 PM, Andriy Gapon a...@freebsd.org wrote:
on 03/12/2010 07:20 Brandon Gooch said the following:
I've been tinkering with DTrace a bit, and I've notice something
peculiar on each system I've tried it on.
Sending ^C from the keyboard in the terminal (console, XTerm, Konsole)
produces no output [1].
Can you ktrace the dtrace process?
I wonder, could it be that SIGINT from ^C is somehow delivered twice?..
I'll give it a shot in just a bit.
I think you are correct, see below.
For example, while trying out a one-liner (from
http://www.brendangregg.com/DTrace/dtrace_oneliners.txt):
bran...@d820:~$ sudo dtrace -n 'syscall:::entry { @num[execname] = count();
}'
dtrace: description 'syscall:::entry ' matched 514 probes
^C
BTW, sudo might play a role here... Just a thought.
I could see that for sure. I can't believe I hadn't thought of that
right off the bat, but then again I tested while logged in as root
from the console -- I think :/
Human memory is unreliable y'know...
You were absolutely on to it -- sudo appears to be the culprit here. I
ktrace'd both an attempt using sudo and not using sudo (as root).
Snippet of ktrace output when running the aforementioned dtrace
command as root, which works as expected:
8804 initial thread PSIG SIGINT caught handler=0x80065d0d0 mask=0x0 code=0x0
8804 initial thread CALL sigprocmask(SIG_SETMASK,0x7fffe06c,0)
8804 initial thread RET sigprocmask 0
8804 initial thread CALL sigreturn(0x7fffdc90)
8804 initial thread RET sigreturn JUSTRETURN
8804 initial thread CALL fstat(0x1,0x7fffe000)
8804 initial thread STRU struct stat {dev=67174144, ino=120, mode=crw--w
, nlink=1, uid=1001, gid=4, rdev=120, atime=1291504111, stime=1291504111, ctime=
1291504111, birthtime=-1, size=0, blksize=4096, blocks=0, flags=0x0 }
8804 initial thread RET fstat 0
8804 initial thread CALL ioctl(0x1,TIOCGETA,0x7fffe050)
8804 initial thread RET ioctl 0
8804 initial thread CALL write(0x1,0x8029b6000,0x1)
8804 initial thread GIO fd 1 wrote 1 byte
Snippet of ktrace output when running the aforementioned dtrace
command with sudo, which produces no output:
4527 initial thread PSIG SIGINT caught handler=0x80065d0d0 mask=0x0 code=0x0
4527 initial thread CALL sigprocmask(SIG_SETMASK,0x7fffe22c,0)
4527 initial thread RET sigprocmask 0
4527 initial thread CALL sigreturn(0x7fffde50)
4527 initial thread RET sigreturn JUSTRETURN
4527 initial thread PSIG SIGINT caught handler=0x80065d0d0 mask=0x0 code=0x0
4527 initial thread CALL sigprocmask(SIG_SETMASK,0x7fffe22c,0)
4527 initial thread RET sigprocmask 0
4527 initial thread CALL sigreturn(0x7fffde50)
4527 initial thread RET sigreturn JUSTRETURN
4527 initial thread PSIG SIGINT caught handler=0x80065d0d0 mask=0x0 code=0x0
4527 initial thread CALL sigprocmask(SIG_SETMASK,0x7fffe22c,0)
4527 initial thread RET sigprocmask 0
4527 initial thread CALL sigreturn(0x7fffde50)
4527 initial thread RET sigreturn JUSTRETURN
4527 initial thread CALL fstat(0x1,0x7fffe1c0)
4527 initial thread STRU struct stat {dev=67174144, ino=128, mode=crw--w
, nlink=1, uid=1001, gid=4, rdev=128, atime=1291523109, stime=1291523110, ctime=
1291523110, birthtime=-1, size=0, blksize=4096, blocks=0, flags=0x0 }
4527 initial thread RET fstat 0
4527 initial thread CALL ioctl(0x1,TIOCGETA,0x7fffe210)
4527 initial thread RET ioctl 0
4527 initial thread CALL write(0x1,0x8029b6000,0x1)
4527 initial thread GIO fd 1 wrote 1 byte
Well, I'm glad to finally get to the bottom of this, and I want to
apologize for the noise, but I think this is still a gotcha for new
DTrace users, and I hope it can be noted somewhere (perhaps the DTrace
sections on the FreeBSD wiki).
-Brandon
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Re: DTrace: Sending ^C while running script produces no output
On Thu, Dec 2, 2010 at 11:48 PM, Artem Belevich fbsdl...@src.cx wrote:
On Thu, Dec 2, 2010 at 9:46 PM, Artem Belevich fbsdl...@src.cx wrote:
On Thu, Dec 2, 2010 at 9:20 PM, Brandon Gooch
jamesbrandongo...@gmail.com wrote:
I've been tinkering with DTrace a bit, and I've notice something
peculiar on each system I've tried it on.
Sending ^C from the keyboard in the terminal (console, XTerm, Konsole)
produces no output [1].
For example, while trying out a one-liner (from
http://www.brendangregg.com/DTrace/dtrace_oneliners.txt):
I've got two boxes, both running stable-8/amd64.
stable/8 r215749 (+cyclic patch) - reliably produces output, though
for some reason does not count anything for 32-bit apps.
stable/8 r215546 - seems to have the problem you've described. I did
get normal output once out of 10 or so attempts.
Tried on another box, also amd64:
stable/8 r212650 - works fine.
I've rebuilt kernel and world on every DTrace enabled system. I built
from a clean svn checkout. I still see this behavior, although it's
definitely the worst on HEAD:
bran...@x300:/usr/src$ svn info (12-03 22:00)
Path: .
URL: svn://svn.freebsd.org/base/head
Repository Root: svn://svn.freebsd.org/base
Repository UUID: ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f
Revision: 216114
Node Kind: directory
Schedule: normal
Last Changed Author: lstewart
Last Changed Rev: 216114
Last Changed Date: 2010-12-02 00:05:44 -0600 (Thu, 02 Dec 2010)
The following NEVER works on this system running HEAD:
bran...@x300:~$ sudo dtrace -n 'syscall:::entry { @num[execname] = count(); }'
dtrace: description 'syscall:::entry ' matched 514 probes
^C
bran...@x300:~$ (12-03 21:59)
Of course, sending ANY signal to dtrace via pkill or killall promptly
causes dtrace to spit out:
bran...@x300:~$ sudo dtrace -n 'syscall:::entry { @num[execname] = count(); }'
dtrace: description 'syscall:::entry ' matched 514 probes
dbus-daemon 6
syslogd 7
ntpd 8
sendmail 9
hald-addon-storage 10
cut 39
hald 40
mixer44
killall 51
powerd 55
zsh 69
openbox 90
dtrace 109
xterm 172
conky 180
sh 231
sudo457
wpa_supplicant 648
Xorg 1557
firefox-bin1992
bran...@x300:~$ (12-03 22:02)
Very troubling.
Question: Should I be rebuilding my ports (xterm, zsh, ksh, etc...)
after updating to make sure that the proper things are happening when
sending these keyboard interrupts? I'm really grasping here :/
-Brandon
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Re: DTrace: Sending ^C while running script produces no output
On Thu, Dec 2, 2010 at 9:20 PM, Brandon Gooch jamesbrandongo...@gmail.com wrote: I've been tinkering with DTrace a bit, and I've notice something peculiar on each system I've tried it on. Sending ^C from the keyboard in the terminal (console, XTerm, Konsole) produces no output [1]. For example, while trying out a one-liner (from http://www.brendangregg.com/DTrace/dtrace_oneliners.txt): I've got two boxes, both running stable-8/amd64. stable/8 r215749 (+cyclic patch) - reliably produces output, though for some reason does not count anything for 32-bit apps. stable/8 r215546 - seems to have the problem you've described. I did get normal output once out of 10 or so attempts. Given that a recent version seems to be working, it may be worth it to update FreeBSD and try again. --Artem ___ freebsd-hackers@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-hackers To unsubscribe, send any mail to freebsd-hackers-unsubscr...@freebsd.org
Re: DTrace: Sending ^C while running script produces no output
On Thu, Dec 2, 2010 at 9:46 PM, Artem Belevich fbsdl...@src.cx wrote: On Thu, Dec 2, 2010 at 9:20 PM, Brandon Gooch jamesbrandongo...@gmail.com wrote: I've been tinkering with DTrace a bit, and I've notice something peculiar on each system I've tried it on. Sending ^C from the keyboard in the terminal (console, XTerm, Konsole) produces no output [1]. For example, while trying out a one-liner (from http://www.brendangregg.com/DTrace/dtrace_oneliners.txt): I've got two boxes, both running stable-8/amd64. stable/8 r215749 (+cyclic patch) - reliably produces output, though for some reason does not count anything for 32-bit apps. stable/8 r215546 - seems to have the problem you've described. I did get normal output once out of 10 or so attempts. Tried on another box, also amd64: stable/8 r212650 - works fine. --Artem ___ freebsd-hackers@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-hackers To unsubscribe, send any mail to freebsd-hackers-unsubscr...@freebsd.org
