Tasks
With each successful login into a project, a new task is created that contains the login process. The task is a process collective that represents a set of work over time. A task can also be viewed as a workload component.
Each process is a member of one task, and each task is associated with one project.
Figure 6-1 Project and Task Tree
All operations on sessions, such as signal delivery, are also supported on tasks. You can also bind tasks to processor sets and set their scheduling priorities and classes, which modifies all current and subsequent processes in the task.
Tasks are created at login (see login(1)), by cron(1M), by newtask(1), and by setproject(3PROJECT).
The extended accounting facility can provide accounting data for processes that are aggregated at the task level.
Commands Used to Administer Projects and Tasks
Command | Description |
|---|---|
projects(1) | Prints the project membership of a user. |
newtask(1) | Executes the user's default shell or specified command, placing the execution command in a new task that is owned by the specified project. newtask can also be used to modify the task and the project binding for a running process. |
projadd(1M) | Adds a new project entry to the /etc/project file. projadd creates a project entry only on the local system. projadd cannot change information that is supplied by the network name service. |
projmod(1M) | Modifies a project's information on the local system. projmod cannot change information that is supplied by the network name service. However, the command does verify the uniqueness of the project name and project ID against the external name service. |
projdel(1M) | Deletes a project from the local system. projdel cannot change information that is supplied by the network name service. |
Command Options Used With Projects and Tasks
ps
Use ps -o to display task and project IDs. For example, to view the project ID, type the following:
# ps -o user,pid,uid,projid USER PID UID PROJID jtd 89430 124 4113 |
id
Use id -p to print the current project ID in addition to the user and group IDs. If the user operand is provided, the project associated with that user's normal login is printed:
# id -p uid=124(jtd) gid=10(staff) projid=4113(booksite) |
pgrep and pkill
To match only processes with a project ID in the specific list, type the following:
# pgrep -J projidlist # pkill -J projidlist |
To match only processes with a task ID in the specific list, type the following:
# pgrep -T taskidlist # pkill -T taskidlist |
prstat
To display various statistics for processes and projects that are currently running on your system, type the following:
% prstat -J
PID USERNAME SIZE RSS STATE PRI NICE TIME CPU PROCESS/NLWP
21634 jtd 5512K 4848K cpu0 44 0 0:00.00 0.3% prstat/1
324 root 29M 75M sleep 59 0 0:08.27 0.2% Xsun/1
15497 jtd 48M 41M sleep 49 0 0:08.26 0.1% adeptedit/1
328 root 2856K 2600K sleep 58 0 0:00.00 0.0% mibiisa/11
1979 jtd 1568K 1352K sleep 49 0 0:00.00 0.0% csh/1
1977 jtd 7256K 5512K sleep 49 0 0:00.00 0.0% dtterm/1
192 root 3680K 2856K sleep 58 0 0:00.36 0.0% automountd/5
1845 jtd 24M 22M sleep 49 0 0:00.29 0.0% dtmail/11
1009 jtd 9864K 8384K sleep 49 0 0:00.59 0.0% dtwm/8
114 root 1640K 704K sleep 58 0 0:01.16 0.0% in.routed/1
180 daemon 2704K 1944K sleep 58 0 0:00.00 0.0% statd/4
145 root 2120K 1520K sleep 58 0 0:00.00 0.0% ypbind/1
181 root 1864K 1336K sleep 51 0 0:00.00 0.0% lockd/1
173 root 2584K 2136K sleep 58 0 0:00.00 0.0% inetd/1
135 root 2960K 1424K sleep 0 0 0:00.00 0.0% keyserv/4
PROJID NPROC SIZE RSS MEMORY TIME CPU PROJECT
10 52 400M 271M 68% 0:11.45 0.4% booksite
0 35 113M 129M 32% 0:10.46 0.2% system
Total: 87 processes, 205 lwps, load averages: 0.05, 0.02, 0.02
|
To display various statistics for processes and tasks that are currently running on your system, type the following:
% prstat -T
PID USERNAME SIZE RSS STATE PRI NICE TIME CPU PROCESS/NLWP
23023 root 26M 20M sleep 59 0 0:03:18 0.6% Xsun/1
23476 jtd 51M 45M sleep 49 0 0:04:31 0.5% adeptedit/1
23432 jtd 6928K 5064K sleep 59 0 0:00:00 0.1% dtterm/1
28959 jtd 26M 18M sleep 49 0 0:00:18 0.0% .netscape.bin/1
23116 jtd 9232K 8104K sleep 59 0 0:00:27 0.0% dtwm/5
29010 jtd 5144K 4664K cpu0 59 0 0:00:00 0.0% prstat/1
200 root 3096K 1024K sleep 59 0 0:00:00 0.0% lpsched/1
161 root 2120K 1600K sleep 59 0 0:00:00 0.0% lockd/2
170 root 5888K 4248K sleep 59 0 0:03:10 0.0% automountd/3
132 root 2120K 1408K sleep 59 0 0:00:00 0.0% ypbind/1
162 daemon 2504K 1936K sleep 59 0 0:00:00 0.0% statd/2
146 root 2560K 2008K sleep 59 0 0:00:00 0.0% inetd/1
122 root 2336K 1264K sleep 59 0 0:00:00 0.0% keyserv/2
119 root 2336K 1496K sleep 59 0 0:00:02 0.0% rpcbind/1
104 root 1664K 672K sleep 59 0 0:00:03 0.0% in.rdisc/1
TASKID NPROC SIZE RSS MEMORY TIME CPU PROJECT
222 30 229M 161M 44% 0:05:54 0.6% group.staff
223 1 26M 20M 5.3% 0:03:18 0.6% group.staff
12 1 61M 33M 8.9% 0:00:31 0.0% group.staff
1 33 85M 53M 14% 0:03:33 0.0% system
Total: 65 processes, 154 lwps, load averages: 0.04, 0.05, 0.06
|
Note - The -J and -T options cannot be used together.
Using cron and su With Projects and Tasks
cron
The cron command issues a settaskid to ensure that each cron, at, and batch job executes in a separate task, with the appropriate default project for the submitting user. Also, the at and batch commands capture the current project ID and ensure that the project ID is restored when running an at job.
su
To switch the user's default project (and thus create a new task) as part of simulating a login, type the following:
# su - user |
To retain the project ID of the invoker, issue su without the - flag.
# su user |
Project Administration Examples
How to Define a Project and View the Current Project
This example shows how to use the projadd and projmod commands.
Become superuser.
View the default /etc/project file on your system.
# cat /etc/project system:0:::: user.root:1:::: noproject:2:::: default:3:::: group.staff:10::::
Add a project that is called booksite and assign it to a user who is named mark with project ID number 4113.
# projadd -U mark -p 4113 booksite
View the /etc/project file again to check for the project addition.
# cat /etc/project system:0:::: user.root:1:::: noproject:2:::: default:3:::: group.staff:10:::: booksite:4113::mark::
Add a comment that describes the project in the comment field.
# projmod -c `Book Auction Project' booksite
View the changes in the /etc/project file.
# cat /etc/project system:0:::: user.root:1:::: noproject:2:::: default:3:::: group.staff:10:::: booksite:4113:Book Auction Project:mark::