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1
vote
0answers
45 views

How to debug a semop failure?

Using a 2.6.30-gentoo-r4 Linux a very complex system of php code is executed (with 4.4.9-pl0-gentoo and 5.2.10-pl0-gentoo), which occasionally runs into a semaphore blocking problem. The call to the ...
6
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1answer
5k 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
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3answers
14k views

what is the difference between spin locks and semaphores?

What are the basic differences between spin locks and semaphores in action?
2
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3answers
4k 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
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6answers
5k 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?