Top "Futex" questions

"A futex (short for “fast userspace mutex”) is a kernel system call that programmers can use to implement basic locking, or as a building block for higher-level locking abstractions such as semaphores and POSIX mutexes or condition variables.

What is the difference between FUTEX_WAIT and FUTEX_WAIT_PRIVATE?

I have been tracing a process with strace and have seen entries such as: futex(0x7ffff79b3e00, FUTEX_…

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The futex facility returned an unexpected error code?

Two threads in same process using rwlock object stored in shared memory encounter crash during pthreads stress test. I spent …

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Why is a pthread mutex considered "slower" than a futex?

Why are POSIX mutexes considered heavier or slower than futexes? Where is the overhead coming from in the pthread mutex …

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Java periodically hangs at futex and very low IO output

Currently my application periodically blocked in IO , and the output is very low . I use some command to trace the …

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How to debug a futex contention shown in strace?

I'm debugging an issue in a multi-threaded linux process, where a certain thread appears to not execute for few seconds. …

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High system CPU usage when contending futex

I have observed that when the linux futexes are contended, the system spends A LOT of time in the spinlocks. …

linux spinlock futex
Python: Process hangs with futex(0x2a5fcc0, FUTEX_WAIT_PRIVATE, 0, NULL in multithreading

So I have a Queue : q = Queue.Queue() And I'm putting some items in it. items = ["First", "Second"] for val …

python multithreading queue futex
Futex based locking mechanism

Somebody can tell me an example of using locking mechanism based on futex? (for muticore x86 CPU, CentOS)

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Python hangs in futex calls

I have a Python daemon running in production. It employs between 7 and 120 threads. Recently the smallest instance (7 threads) started to …

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