Bug 946864 - The man page for "ps" does not indicate what a lowercase "T" means (probably "traced by another user") [NEEDINFO]
Summary: The man page for "ps" does not indicate what a lowercase "T" means (probably ...
Keywords:
Status: CLOSED EOL
Alias: None
Product: Fedora
Classification: Fedora
Component: kernel
Version: 19
Hardware: Unspecified
OS: Unspecified
unspecified
unspecified
Target Milestone: ---
Assignee: Kernel Maintainer List
QA Contact: Fedora Extras Quality Assurance
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2013-03-31 13:51 UTC by David Tonhofer
Modified: 2015-02-18 11:10 UTC (History)
11 users (show)

Fixed In Version:
Doc Type: Bug Fix
Doc Text:
Clone Of:
Environment:
Last Closed: 2015-02-18 11:10:38 UTC
Type: Bug
Embargoed:
jforbes: needinfo?


Attachments (Terms of Use)

Description David Tonhofer 2013-03-31 13:51:13 UTC
Description of problem:
=======================

The man page for "ps" does not indicate what a lowercase "T" means (probably "traced by another user")

Man page has to be updated.

Version-Release number of selected component (if applicable):
=============================================================

procps-3.2.8-28.20110302git.fc17.x86_64

Comment 1 Jaromír Cápík 2013-06-18 14:43:52 UTC
Hello David.

Is it a switch or a column 'value' you're talking about? Please, be more specific.

Thank you.

Regards,
Jaromir.

Comment 2 David Tonhofer 2013-06-18 15:01:02 UTC
Hi Jaromir,

You are right, that's pretty unclear.

It's the value (status) displayed. For example:

USER       PID %CPU %MEM    VSZ   RSS TTY      STAT START   TIME COMMAND
root         2  0.0  0.0      0     0 ?        S    08:51   0:00 [kthreadd]
root         3  0.0  0.0      0     0 ?        S    08:51   0:00  \_ [kso
root         5  0.0  0.0      0     0 ?        S<   08:51   0:00  \_ [kwo
root         7  0.0  0.0      0     0 ?        S<   08:51   0:00  \_ [kwo
root         8  0.0  0.0      0     0 ?        S    08:51   0:04  \_ [mig
....
hobbes    1414  0.0  0.4 425468 17452 ?        t    08:52   0:06 /usr/bin/klipper

Here "klipper" is being traced by root.

The manual just says:

----
T    stopped, either by a job control signal or because it is being traced
----

Comment 3 Jaromír Cápík 2013-06-18 17:14:34 UTC
Ok. Now it's clear. It seems the same applies to procps-ng. Gonna check and fix the manpage.

Thank you for the report.

Regards,
Jaromir.

Comment 4 Fedora End Of Life 2013-07-04 05:53:39 UTC
This message is a reminder that Fedora 17 is nearing its end of life.
Approximately 4 (four) weeks from now Fedora will stop maintaining
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Comment 5 Fedora End Of Life 2013-08-01 17:11:02 UTC
Fedora 17 changed to end-of-life (EOL) status on 2013-07-30. Fedora 17 is 
no longer maintained, which means that it will not receive any further 
security or bug fix updates. As a result we are closing this bug.

If you can reproduce this bug against a currently maintained version of 
Fedora please feel free to reopen this bug against that version.

Thank you for reporting this bug and we are sorry it could not be fixed.

Comment 6 Fedora End Of Life 2013-12-21 15:27:35 UTC
This message is a reminder that Fedora 18 is nearing its end of life.
Approximately 4 (four) weeks from now Fedora will stop maintaining
and issuing updates for Fedora 18. It is Fedora's policy to close all
bug reports from releases that are no longer maintained. At that time
this bug will be closed as WONTFIX if it remains open with a Fedora 
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Package Maintainer: If you wish for this bug to remain open because you
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Thank you for reporting this issue and we are sorry that we may not be 
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Although we aim to fix as many bugs as possible during every release's 
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Comment 7 Jaromír Cápík 2014-04-03 18:24:18 UTC
It seems the kernel documentation doesn't cover the lowercase 't':

https://www.kernel.org/doc/Documentation/filesystems/proc.txt

... as you can see, the docs list just the "RSDZT" letters and the procps code additionally adds a combination of "<NLsl+".

Comment 8 Jaromír Cápík 2014-04-03 18:31:52 UTC
The documentation contains teh following ....

-------------------------------
 State                       state (R is running, S is sleeping, D is sleeping
                             in an uninterruptible wait, Z is zombie,
			     T is traced or stopped)
-------------------------------

Changing the component to kernel to get their statement and/or a documentation fix.

Comment 9 Josh Boyer 2014-04-03 19:17:42 UTC
/*
 * The task state array is a strange "bitmap" of
 * reasons to sleep. Thus "running" is zero, and
 * you can test for combinations of others with
 * simple bit tests.
 */
static const char * const task_state_array[] = {
        "R (running)",          /*   0 */
        "S (sleeping)",         /*   1 */
        "D (disk sleep)",       /*   2 */
        "T (stopped)",          /*   4 */
        "t (tracing stop)",     /*   8 */
        "Z (zombie)",           /*  16 */
        "X (dead)",             /*  32 */
};

is the array present in fs/proc/array.c.  What 'tracing stop' means, I have no idea.  Oleg would likely know though.

Comment 10 Josh Boyer 2014-04-03 19:18:33 UTC
Looking at include/linux/sched.h it seems 'T' is STOPPED and 't' is TRACED.  Why it's called 'tracing stop'... no idea.

Comment 11 Oleg Nesterov 2014-04-03 20:06:13 UTC
(In reply to Josh Boyer from comment #10)
>
> Looking at include/linux/sched.h it seems 'T' is STOPPED and 't' is TRACED.

Yes, exactly. So "t" means stopped by debugger.

> Why it's called 'tracing stop'... no idea.

... and too late to change ;)

Comment 12 Jaromír Cápík 2014-04-04 15:55:02 UTC
Thanks guys. I'll document it in the procps-ng manuals. Please, do the same in case of the kernel documentation.

Comment 13 Jaromír Cápík 2014-04-04 16:57:42 UTC
Just a short clarification ... the following is the current description of the capital T in the procps-ng manual.

T - stopped, either by a job control signal or because it is being traced

... so, if I understand correctly, it needs to be split to the following two descriptions

T - stopped by a job control signal
t - stopped by debugger during the tracing

Is that correct?

Comment 14 Oleg Nesterov 2014-04-05 13:01:34 UTC
(In reply to Jaromír Cápík from comment #13)
>
> ... so, if I understand correctly, it needs to be split to the following two
> descriptions
> 
> T - stopped by a job control signal

Yes. SIGCONT can wake it up, other signals can't (except SIGKILL).

> t - stopped by debugger during the tracing
> 
> Is that correct?

Yes. But just in case, the task still can be stopped by jctl, but
since it runs under debugger it will actually stop in TASK_TRACED
and thus it will be reported as "t" in /proc. SIGCONT won't work.

SIGKILL should wake it up (and kill ;) in both cases.

Comment 15 Oleg Nesterov 2014-04-05 13:09:03 UTC
(In reply to Oleg Nesterov from comment #14)
>
> Yes. But just in case, the task still can be stopped by jctl, but
> since it runs under debugger it will actually stop in TASK_TRACED
> and thus it will be reported as "t" in /proc.

To clarify, this is true starting from (approx) v3.0 kernel. Previously
a traced task could stop in TASK_STOPPED, although this state was not
"stable", it could be silently turned into TASK_TRACED.

Comment 16 Jaromír Cápík 2014-04-08 13:45:03 UTC
I think the description doesn't need to be so detailed in case of the procps-ng manual. But feel free to document that behaviour in the kernel docs.

Comment 17 Fedora Update System 2014-04-08 14:45:58 UTC
procps-ng-3.3.8-13.fc19 has been submitted as an update for Fedora 19.
https://admin.fedoraproject.org/updates/procps-ng-3.3.8-13.fc19

Comment 18 Fedora Update System 2014-04-08 14:46:44 UTC
procps-ng-3.3.8-17.fc20 has been submitted as an update for Fedora 20.
https://admin.fedoraproject.org/updates/procps-ng-3.3.8-17.fc20

Comment 19 lnie 2014-04-09 04:03:00 UTC
procps-ng-3.3.8-17.fc20 works

Comment 20 Fedora Update System 2014-04-15 15:40:40 UTC
procps-ng-3.3.8-17.fc20 has been pushed to the Fedora 20 stable repository.  If problems still persist, please make note of it in this bug report.

Comment 21 Justin M. Forbes 2014-05-21 19:30:02 UTC
*********** MASS BUG UPDATE **************

We apologize for the inconvenience.  There is a large number of bugs to go through and several of them have gone stale.  Due to this, we are doing a mass bug update across all of the Fedora 19 kernel bugs.

Fedora 19 has now been rebased to 3.14.4-100.fc19.  Please test this kernel update (or newer) and let us know if you issue has been resolved or if it is still present with the newer kernel.

If you have moved on to Fedora 20, and are still experiencing this issue, please change the version to Fedora 20.

If you experience different issues, please open a new bug report for those.

Comment 22 Fedora Update System 2014-06-21 02:58:37 UTC
procps-ng-3.3.8-13.fc19 has been pushed to the Fedora 19 stable repository.  If problems still persist, please make note of it in this bug report.

Comment 23 Fedora End Of Life 2015-01-09 22:32:55 UTC
This message is a notice that Fedora 19 is now at end of life. Fedora 
has stopped maintaining and issuing updates for Fedora 19. It is 
Fedora's policy to close all bug reports from releases that are no 
longer maintained. Approximately 4 (four) weeks from now this bug will
be closed as EOL if it remains open with a Fedora 'version' of '19'.

Package Maintainer: If you wish for this bug to remain open because you
plan to fix it in a currently maintained version, simply change the 'version' 
to a later Fedora version.

Thank you for reporting this issue and we are sorry that we were not 
able to fix it before Fedora 19 is end of life. If you would still like 
to see this bug fixed and are able to reproduce it against a later version 
of Fedora, you are encouraged  change the 'version' to a later Fedora 
version prior this bug is closed as described in the policy above.

Although we aim to fix as many bugs as possible during every release's 
lifetime, sometimes those efforts are overtaken by events. Often a 
more recent Fedora release includes newer upstream software that fixes 
bugs or makes them obsolete.

Comment 24 Fedora End Of Life 2015-02-18 11:10:38 UTC
Fedora 19 changed to end-of-life (EOL) status on 2015-01-06. Fedora 19 is
no longer maintained, which means that it will not receive any further
security or bug fix updates. As a result we are closing this bug.

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