context-switch

Win32: Atomic Execution of Code Block

I have two system calls GetSystemTime() and GetThreadTimes() that I need to calculate the CPU utilization by a given Win32 thread. For the sake of accuracy, I need to ensure that both GetSystemTime() and GetThreadTimes() are executed atomically; i.e. there should be no context switch in between a call to GetSystemTime() & GetThreadTimes...

What is saved in a context switch?

What is exactly saved and restored in a context switch between two threads in the same process between two processes ...

GCC: Force a function call after every instruction (for multithreaded testing)?

Hi, I'm trying to test a rather threading-sensitive area in my program and was wondering if there's a way to force gcc to insert a call after every instruction it emits so that I can manually yield to a different thread? Thanks, Robert ...

C++ context switch and mutex problem

Ok.. here is some background on the issue. I have some 'critical' code that i'm trying to protect with a mutex. It goes something like this Mutex.Lock() // critical code // some file IO Mutex.Unlock(). Now the issue is that my program seems to be 'stuck' due to this. Let me explain with an example. Thread_1 comes in; and go to Mutex...

Write a C program to measure time spent in context switch in Linux OS.

Can we write a c program to find out time spent in context switch in Linux? Could you please share code if you have one? Thanks ...

Counting context switches per thread

Is there a way to see how many context switches each thread generates? (both in and out if possible) Either in X/s, or to let it run and give aggregated data after some time. (either on linux or on windows) I have found only tools that give aggregated context-switching number for whole os or per process. My program makes many context s...

How expensive is a context switch? Is it better to implement a manual task switch than to rely on OS threads?

The title says it all. Imagine I have two (three, four, whatever) tasks that have to run in parallel. Now, the easy way to do this would be to create separate threads and forget about it. But on a plain old single-core CPU that would mean a lot of context switching - and we all know that context switching is big, bad, slow, and generally...

Can my thread help the OS decide when to context switch it out?

I am working on a threaded application on Linux in C++ which attempts to be real time, doing an action on a heartbeat, or as close to it as possible. In practice, I find the OS is swapping out my thread and causing delays of up to a tenth of a second while it is switched out, causing the heartbeat to be irregular. Is there a way my thr...

Are threads from multiple processes actually running at the same time

In a Windows operating system with 2 physical x86/amd64 processors (P0 + P1), running 2 processes (A + B), each with two threads (T0 + T1), is it possible (or even common) to see the following: P0:A:T0 running at the same time as P1:B:T0 then, after 1 (or is that 2?) context switch(es?) P0:B:T1 running at the same time as P1:A:T1 In ...

Context switch time - Role of RTOS and Processor

Does the RTOS play a major role or processor play a major role in determining the time for context switch ? What is the percentage of share between these two major players in determining the context switch time . Can anyone tell with respect to uC/OS-II RTOS ? ...

Lowest context switch time

Which processor has the best context switch time ? ...