RCU_READ_LOCK_BH_HEL(9) Driver Basics RCU_READ_LOCK_BH_HEL(9)NAME
rcu_read_lock_bh_held - might we be in RCU-bh read-side critical section?
SYNOPSIS
int rcu_read_lock_bh_held(void);
ARGUMENTS
void
no arguments
DESCRIPTION
Check for bottom half being disabled, which covers both the CONFIG_PROVE_RCU and not cases. Note that if someone uses rcu_read_lock_bh, but
then later enables BH, lockdep (if enabled) will show the situation.
Check debug_lockdep_rcu_enabled to prevent false positives during boot.
COPYRIGHT Kernel Hackers Manual 2.6. July 2010 RCU_READ_LOCK_BH_HEL(9)
Check Out this Related Man Page
CRITICAL_ENTER(9) BSD Kernel Developer's Manual CRITICAL_ENTER(9)NAME
critical_enter, critical_exit -- enter and exit a critical region
SYNOPSIS
#include <sys/param.h>
#include <sys/systm.h>
void
critical_enter(void);
void
critical_exit(void);
DESCRIPTION
These functions are used to prevent preemption in a critical region of code. All that is guaranteed is that the thread currently executing
on a CPU will not be preempted. Specifically, a thread in a critical region will not migrate to another CPU while it is in a critical
region. The current CPU may still trigger faults and exceptions during a critical section; however, these faults are usually fatal.
The critical_enter() and critical_exit() functions manage a per-thread counter to handle nested critical sections. If a thread is made
runnable that would normally preempt the current thread while the current thread is in a critical section, then the preemption will be
deferred until the current thread exits the outermost critical section.
Note that these functions are not required to provide any inter-CPU synchronization, data protection, or memory ordering guarantees and thus
should not be used to protect shared data structures.
These functions should be used with care as an infinite loop within a critical region will deadlock the CPU. Also, they should not be inter-
locked with operations on mutexes, sx locks, semaphores, or other synchronization primitives. One exception to this is that spin mutexes
include a critical section, so in certain cases critical sections may be interlocked with spin mutexes.
HISTORY
These functions were introduced in FreeBSD 5.0.
BSD October 5, 2005 BSD
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)