03-25-2004
I gave it some thought, and based on your reply I would like to do the following: "the parent could create a pipe with each of them and send a signal whenever you've just sent a command down the pipe"
-- I have to guarantee that when I send the command down the pipe and then the signal, this is all done atomically, I would also like to use semaphores to guard this section of the code, I do not want to travel the disabling interrupts route or busy waiting.
If this possible can someone point me to some sample code or resources for all tasks, creation of pipes and writing commands to it, signaling the process and using semaphores.
Thank you.
FI
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RENICE(1) User Commands RENICE(1)
NAME
renice - alter priority of running processes
SYNOPSIS
renice [-n] priority [-g|-p|-u] identifier...
DESCRIPTION
renice alters the scheduling priority of one or more running processes. The first argument is the priority value to be used. The other
arguments are interpreted as process IDs (by default), process group IDs, user IDs, or user names. renice'ing a process group causes all
processes in the process group to have their scheduling priority altered. renice'ing a user causes all processes owned by the user to have
their scheduling priority altered.
OPTIONS
-n, --priority priority
Specify the scheduling priority to be used for the process, process group, or user. Use of the option -n or --priority is optional,
but when used it must be the first argument.
-g, --pgrp
Interpret the succeeding arguments as process group IDs.
-p, --pid
Interpret the succeeding arguments as process IDs (the default).
-u, --user
Interpret the succeeding arguments as usernames or UIDs.
-V, --version
Display version information and exit.
-h, --help
Display help text and exit.
EXAMPLES
The following command would change the priority of the processes with PIDs 987 and 32, plus all processes owned by the users daemon and
root:
renice +1 987 -u daemon root -p 32
NOTES
Users other than the superuser may only alter the priority of processes they own. Furthermore, an unprivileged user can only increase the
``nice value'' (i.e., choose a lower priority) and such changes are irreversible unless (since Linux 2.6.12) the user has a suitable
``nice'' resource limit (see ulimit(1) and getrlimit(2)).
The superuser may alter the priority of any process and set the priority to any value in the range -20 to 19. Useful priorities are: 19
(the affected processes will run only when nothing else in the system wants to), 0 (the ``base'' scheduling priority), anything negative
(to make things go very fast).
FILES
/etc/passwd
to map user names to user IDs
SEE ALSO
nice(1), getpriority(2), setpriority(2), credentials(7), sched(7)
HISTORY
The renice command appeared in 4.0BSD.
AVAILABILITY
The renice command is part of the util-linux package and is available from Linux Kernel Archive <https://www.kernel.org/pub/linux/utils
/util-linux/>.
util-linux July 2014 RENICE(1)