PREEMPT(9) BSD Kernel Developer's Manual PREEMPT(9)NAME
preempt, yield -- general preempt and yield functions
SYNOPSIS
#include <sys/sched.h>
void
preempt(void);
#include <sys/proc.h>
void
yield(void);
DESCRIPTION
The preempt() function puts the current LWP back on the system run queue and performs an involuntary context switch. The yield() function is
mostly same as preempt(), except that it performs a voluntary context switch.
These functions drop the kernel lock before switching and re-acquire it before returning.
BSD July 3, 2007 BSD
Check Out this Related Man Page
CPU_NEED_RESCHED(9) BSD Kernel Developer's Manual CPU_NEED_RESCHED(9)NAME
cpu_need_resched -- context switch notification
SYNOPSIS
#include <sys/cpu.h>
void
cpu_need_resched(struct cpu_info *ci, int flags);
DESCRIPTION
The cpu_need_resched() function is the machine-independent interface for the scheduler to notify machine-dependent code that a context switch
from the current LWP, on the cpu ci, is required. This event may occur if a higher priority LWP appears on the run queue or if the current
LWP has exceeded its time slice.
If RESCHED_KPREEMPT flag is specified in flags and __HAVE_PREEMPTION C pre-processor macro is defined in <machine/intr.h>, machine-dependent
code should make a context switch happen as soon as possible even if the cpu is running the kernel code.
If RESCHED_IMMED flag is specified in flags, machine-dependent code should make a context switch happen as soon as possible. In that case,
for example, if ci is not the current processor, cpu_need_resched() typically issues an inter processor call to the processor to make it
notice the need of a context switch as soon as possible.
Typically, the cpu_need_resched() function will perform the following operations:
o Set a per-processor flag which is checked by userret(9) when returning to user-mode execution.
o Post an asynchronous software trap (AST).
o Send an inter processor interrupt to wake up cpu_idle(9).
SEE ALSO sched_4bsd(9), userret(9)BSD July 31, 2010 BSD
Dear all,
In a bash script, I grep a filename from an UTF8 encoded file:
LIST=`grep ^source $FILE | tr "\t" " " | cut -d " " -f 2 | sed -e 's,~,\$HOME,g'`
The result is
# echo $LIST
$HOME/.mail_aliases_seminaire_MMMG
Then I try to access it:
#ls $LIST
ls: cannot access... (3 Replies)
I'm trying to execute something like this:
exec perl -i -pe 's/\015/\012/g' '${file}'
in my expect script and I get:
error "invalid command name \"perl\".
however, if I run
perl -i -pe 's/\015/\012/g' "/Users/Shared/menu-items.txt"
directly in my terminal, it runs fine. I'm an... (4 Replies)
Discussion started by: dpouliot
4 Replies
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I have two Linux machines, Linux1 and Linux2. They both have two NFS mounts. We'll call them /scratch1 and /scratch2. And they both reside on the same NetApp filer. If I copy a 512Mb file from /scratch1 to /scratch2 while logged on Linux1 it takes 40s. However if I scp this file from... (1 Reply)
Good evening, Im newbie at unix specially with awk
From an scheduler program called Autosys i want to extract some data reading an inputfile that comprises jobs names, then formating the output to columns for example
1.
This is the inputfile:
$ more MapaRep.txt
ds_extra_nikira_usuarios... (18 Replies)
In this script:
#!/bin/bash
# bird
read -p "Enter name of a bird "
REPLY=$REPLY
birdname="duck sparrow hawk"
for i in $birdname
do
if ]
then
echo "Yes, that is a bird."
else
echo "That is not a bird."
fi
done
I get... (9 Replies)