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5
votes
1answer
3k views

How to get proccesses currently running semaphores by /proc?

I wonder how to get processes currently running semaphores by /proc ? I guess it's possible by SysVIPC subdirectory.But I don't know how to use this commands. Ubuntu 12.10
3
votes
1answer
5k views

How do I increase the number of semaphore arrays in Linux?

In a Debian lenny server running postgresql, I noticed that a lack of semaphore arrays is preventing Apache from starting up. Looking at the limits, I see 128 arrays used out of 128 arrays maximum, ...
8
votes
3answers
13k views

what is the difference between spin locks and semaphores?

What are the basic differences between spin locks and semaphores in action?
2
votes
3answers
3k views

Why are spin locks good choices in Linux Kernel Design instead of something more common in userland code, such as semaphore or mutex?

I understand that Spinlocks are real waste in Linux Kernel Design. I would like to know why is it like spin locks are good choices in Linux Kernel Design instead of something more common in userland ...
23
votes
5answers
4k views

What Unix commands can be used as a semaphore/lock?

I want to run multiple Bash shell scripts in parallel. However, I want to avoid race conditions. What Unix commands are truly atomic that I could use for this purpose, and how can I use them?