WAKE_UP_PROCESS(9) Driver Basics WAKE_UP_PROCESS(9)NAME
wake_up_process - Wake up a specific process
SYNOPSIS
int wake_up_process(struct task_struct * p);
ARGUMENTS
p
The process to be woken up.
DESCRIPTION
Attempt to wake up the nominated process and move it to the set of runnable processes. Returns 1 if the process was woken up, 0 if it was
already running.
It may be assumed that this function implies a write memory barrier before changing the task state if and only if any tasks are woken up.
COPYRIGHT Kernel Hackers Manual 2.6. July 2010 WAKE_UP_PROCESS(9)
Check Out this Related Man Page
sem_post(2) System Calls Manual sem_post(2)NAME
sem_post - unlock a POSIX semaphore
SYNOPSIS DESCRIPTION
is used to post the semaphore referenced by sem. The calling thread will not return from its call to unless it can either: increment the
semaphore value, if there are no blocked threads on this semaphore; give the semaphore to a blocked thread, if there are any blocked
threads on this semaphore; or have an error condition.
If the semaphore value is < 0, the semaphore has blocked threads, waiting for it to become available (the absolute value of the semaphore's
value indicates the number of waiters at that moment). If the semaphore value is >= 0, the semaphore has no waiters.
If the semaphore has no waiters at the time its value is checked, the semaphore's value will be atomically incremented, with respect to the
checking of its value, up to its maximum value as specified by If the semaphore has waiters at the time its value is checked, the semaphore
value is not changed. Instead, the calling thread will attempt to wake up a waiter. If the semaphore has waiters having realtime priori-
ties, the thread must wake up the highest priority waiter. Otherwise the thread at the head of the channel queue is woken up.
When a waiter is successfully woken, the semaphore being posted will be given to the woken waiter. In other words, the state of the sema-
phore remains unchanged. Instead, the semaphore being posted will be inherited by the waiter being woken from this call to
If the specified semaphore referred to by sem is a named semaphore, then this semaphore must have been opened by the calling process with
The calling process must have both read and write permissions on the semaphore to perform this operation. The routine may be called asyn-
chronously, i.e. from a signal handler.
To use this function, link in the realtime library by specifying on the compiler or linker command line.
EXAMPLES
The following call to will post the semaphore sem.
RETURN VALUE
A successful call to will return 0 and the calling thread would have posted the semaphore. Otherwise, the call to will return -1 with
errno set to the appropriate value of the error condition.
ERRORS
fails and does not perform the requested operation if any of the following conditions are encountered:
[EPERM] The calling process does not have the privileges necessary to post the semaphore.
[EINVAL] The argument sem does not refer to a valid semaphore.
SEE ALSO
<semaphore.h>.
STANDARDS CONFORMANCE sem_post(2)
Hi all,
I want to create a new user and grant him ONLY transfer files access to a specific directory where he can only upload and read the files. He should be restricted to this activity only.
Regards (6 Replies)
Hi everyone,
I know the following questions are noobish questions but I am asking them because I am confused about the basics of history behind UNIX and LINUX.
Ok onto business, my questions are-:
Was/Is UNIX ever an open source operating system ?
If UNIX was... (21 Replies)
Hi,
Last 2 weeks I have searched many forums and i haven't found the answer for the question:
How to get all command output to Putty title?
Needed it for other programs to know when some jobs on a server is done and is it done right or wrong. Plink stdout and stdin wasn't working, i used many... (1 Reply)
anyone have any idea how do to this with auth_attr?
I suspect if I grant him
solaris.device.:RO::Device Allocation::help=DevAllocHeader.html
that will work but I'm unsure. Just looking for a second opinion. (10 Replies)
I am looking for a stable, reliable system to replace my current Windows systems in the home. These are simple systems that I purchased from the local Big Box store.
I have heard many good things about Unix and it's various children and it sounds like a good option to me. I have worked... (2 Replies)
We have a lot of scripts using cut as :
cut -c 0-8 --works for cut (GNU coreutils) 5.97, but does not work for cut (GNU coreutils) 8.4.
Gives error -
cut: fields and positions are numbered from 1
Try `cut --help' for more information.
The position needs to start with 1 for later... (6 Replies)
I've got a problem with a proxy configuration. We have an LDAP group that lists all users who are authorised to use the proxy to FTP (usually Filezilla) out to the world, and by implication those not in the group should be denied. My users are delighted that this has been enabled and those that... (9 Replies)
hi folks,
how to using tar with exclude directory and compress it using tar.Z
i only know how to exclude dir only with this command below:
tar -cvf /varios/restore/test.tar -X excludefile.txt /jfma/test1/
how to compress it using 1 command?
Thanx
Please use CODE tags as... (6 Replies)
Hello All,
I had recently learnt a bit of Docker(which provides containerization process).
Here are some of my learning points from it.
Let us start first with very basic question:
What is Docker:
Docker is a platform for sysadmins and developers to DEPLOY, DEVELOP and RUN applications ... (7 Replies)
What is the point of this? Whenever I close my shell it appends to the history file without adding this. I have never seen it overwrite my history file.
# When the shell exits, append to the history file instead of overwriting it
shopt -s histappend (3 Replies)
Hello for all,
I am testing the behavior of a 32 bit application running on Solaris 5.10 (SPARC), and realize it reaches 4GB of memory and then crashes.
It doesn't matter the amount of used memory as application is intended to perform many transactions; rather, what I want to achieve is to... (2 Replies)