CPU Affinity
Is there a progamatic method to set CPU affinity for a process in c/c++ for the linux operating system. ...
affinity
Mapping logical processors to physical processors
On a dual quad-core GetProcessAffinityMask (or the dialog from "Set affinity" in taskman.exe) will report eight logical processors. How do I find out which logical processor is on which physical processor? Especially: which logical processors are on the same physical processor? EDIT: If it is not possible to do this programmatically, do...
How to set processor affinity on an executable in Windows XP?
I have a quad core system with third party application that once in a while spins several processes (always the same executable but several instances of it) and takes 100% of CPU time. I also have a couple of web services running on the same box (IIS and third party). The problem with the all cores being busy is that it makes this third...
How to set processor affinity from Batch File for Windows XP?
I've got a dual processor machine and I would like to launch an executable via a batch file on both processors. For example: (1) Launch Notepad.exe on Processor 1, and (2) Simultaneously, Notepad.exe on Processor 2 Currently, I'm using the following in my batch file, since my executable was "difficult" to launch and needed a return in...
Why would one CPU core run slower than the others?
I was benchmarking a large scientific application, and found it would sometimes run 10% slower given the same inputs. After much searching, I found the the slowdown only occurred when it was running on core #2 of my quad core CPU (specifically, an Intel Q6600 running at 2.4 GHz). The application is a single-threaded and spends most of ...
Setting affinity in multicore x86 processors.
( I ask because it was before serious SMP and multicore that I studied OS. I like to have some vision of how code is being executed. ) If I have a multicore x86 CPU booting directly into my program. Can someone recommend a website which describes what assembler commands do I have to control affinity? ...
how to set CPU affinity of a program?
Hello everyone, I have a program written in C#, I am using VSTS 2008 + .Net 3.5 + Windows Vista Enterprise x86 to develop a Windows Forms application. My current computer is dual-core CPU, I want to set CPU affinity of my program to run on a specific CPU and free another CPU to do some other job. Any ideas how to do this? Either throug...
Parent window and thread affinity
I'm having a WinForms application where I would like to perform some long-running operations, e.g. imagine Explorer copying 2 big files in parallel. For each of those long-running operations I'm starting a separate UI thread (which includes pumping messages/Application.Run/Application.ExitThread) where I create an instance of the IProgre...
Setting process affinity in kernel mode
How can the CPU affinity of a process be set in kernel module? In user mode there is a syscall sched_setaffinity, but I am looking for the kernel mode equivalent. In the Linux kernel code, there is also a function called sched_setaffinity. It's called from the sys_sched_setaffinity function which is called by system_call. From what i...
how to set CPU affinity of a particular pthread?
Hi, I'd like to specify the cpu-affinity of a particular pthread. All the references I've found so far deal with setting the cpu-affinity of a process (pid_t) not a thread (pthread_t). I tried some experiments passing pthread_t's around and as expected they fail. Am I trying to do something impossible? If not, can you send a pointer ple...
Code for detecting APIC id returns same ids for different logical processors
I run my NT service on an Intel Core2 based Win2k3 machine where I need to iterate through all logical CPUs (all bits in process affinity). To do so I call GetProcessAffinityMask() to retrieve the system affinity mask and then switch the process to each processor in turn: DWORD systemMask; GetProcessAffinityMask( ... &systemMask ); D...
Does set affinity ensure that only one core resources are used?
Hello, I just wanted to find out if setting cpu affinity ensure that the application runs only on that core ? ...
Negate Unsigned Number in Bash
I have a number (hex) and I want the one's complement of it. For example if X = 20 I want bash to perform a negation and return Y = ~X = DF. It doesn't have to be in bash, but it should use a common command line tool that I can wrap into a script. Also note that the numbers should all be unsigned and I'd prefer they don't overflow the...
Do the changes to cpumask using sched_setaffinity() take place immediately
I am writing a linux kernel module that needs to pin two threads on two different cpus. I am planning to use sched_setaffinity() after exporting it in the kernel. Is there any other exported function for the same ? Also, if I set only 1 CPU in the cpumask, will the thread be moved to that cpu with immediate effect ? If not, how do I en...
Does IIS6 or IIS7 suppports client connection affinity to a worker process when using Web Gardens?
We have a .NET 3.5 application that stores sessions "In process". The application works fine when Web Garden in IIS6 is set to 1. However, when we change to 2 or more, users gets kick out and asked to log in again. As far as I have read, this can be solved by storing sessions out of the process (either state server or database). Assumi...
Processor affinity settings for Linux kernel modules?
In Windows, I can set the processor affinity of driver code using KeSetSystemAffinityThread, and check which processor my code is running on using KeGetCurrentProcessorNumber. I'm trying to do something similar in a Linux kernel module, but the only affinity calls I can see are for userland processes. Is there any way to do this, so tha...
Why does NextValue call of performanceCounter change thread affinity mask
Hi. I have a C# project, where I have to both access the current workload of my processor, and ensure, that I run some specific code on every kernel of the processor. My problem is, that accessing the workload of my processor seems to prevent me from correctly assigning a thread affinity mask. I have some code here, that illustrates the...
How to build/mantain an affinity score between 2 users?
I mean analyzing 2 users profiles I get a score that it is reciprocal a.affinity(b) == b.affinity(a) I'd like to know in particular: which schema would u use to implement the affinity table which db mysql, redis,.. which technology would you use to update the affinity score in background? Thanks ...