Interested to Buy Any Domain ? << Click Here >> for more details...
what is the difference between semaphore, mutex &
spinlock?????
- 1 Answers
- 31086 Views
- Patni, I also Faced
- E-Mail Answers
Answer / guest
Kernel Locking Techniques
Semaphores in Linux are sleeping locks. Because they cause a
task to sleep on contention, instead of spin, they are used
in situations where the lock-held time may be long.
Conversely, since they have the overhead of putting a task
to sleep and subsequently waking it up, they should not be
used where the lock-held time is short. Since they sleep,
however, they can be used to synchronize user contexts
whereas spinlocks cannot. In other words, it is safe to
block while holding a semaphore.
A "mutex" (or "mutual exclusion lock") is a signal that two
or more asynchronous processes can use to reserve a shared
resource for exclusive use. The first process that obtains
ownership of the "mutex" also obtains ownership of the
shared resource. Other processes must wait for for the first
process to release it's ownership of the "mutex" before they
may attempt to obtain it.
The most common locking primitive in the kernel is the
spinlock. The spinlock is a very simple single-holder lock.
If a process attempts to acquire a spinlock and it is
unavailable, the process will keep trying (spinning) until
it can acquire the lock. This simplicity creates a small and
fast lock.
| Is This Answer Correct ? | 64 Yes | 7 No |
How to load the old kernel without rebooting server
1. User gaves df -h and the system get hanged. why ? 2. what is the hardlink and softlink mount ? 3. why is portmape should be started ? 4. what is nologin option 5. how to restrict users from accessing nfs ? 6. what is the difference between cpio and tar 7. what are the kernel parameters ? how to find out it ? 8. why we use sysctl.conf ? 9. if we gives init1 from multiuser runlevel, will it affect other users who already logged in to the system ? 10. what will be the available space to use after configuering raid5 with 5 disks each having 5gb spce ?
You want to create a compressed backup of the users' home directories. What utility should you use?
What is the difference between RedHat linux and Fedora and Ubuntu?
How can i recover the linux system after it was crashed by step by step process..
How does the boot process[init levels] work on Linux? How is it different from Solaris?
My Linux server in the two lan card one lan card is ok working but second lan card after restart daily lan card deactivate and then manual activate then properly working but after restart repeat this problem.(Fedora O.S.) Pls tell me solved this problem.
someone already asked 'what is diff between unix & Linux' can I ask the same but more nuanced...I have 7 years app support of unix, have never seen Linux BUT need to bluff my way through in an interview i e say that I have use Linux. What are the most important things I need to know?
what is the difference between semaphore, mutex & spinlock?????
What is the difference between home directory and working directory?
what is difference between inetd and xinetd
1.how to know cpu information on linux system? 2.how to hardware information on linux system? 3.if we add the new user what are the files will be changed? 4.how to remove the cache in squid server ? 5.how to know ur useing 32bit r 64 bit os ? 6.at booting process at init level which file it is reads? 7.if ur system performance is show what can u do ? 8.if ur file system corrupted what can u do ? fsck also not working? 9.how did u do health check in linux? 10.how did u check system performance in linux? 11.how did u create NIS server? give me the steps ? 12.how did u add a packages in linux ? 13.how did u know depended packages for any package useing rpm how u know? 14.how did you monitor cronjobs in linux ? 15.what is the use of logroted? and how did u do ? 16.port no is already in use so what canu do for that in http? 17.how to samba configurated are not ? there are any command for that ? 18.how to create a NTP Client using commands ? not as graphical... 19.how to know how many members are using any service? like ftp are any other services? 20.what is the differences between cmp,diff,comm commands?
Linux Commands 
