Search results
Results From The WOW.Com Content Network
On Linux, the CPU affinity of a process can be altered with the taskset(1) program [3] and the sched_setaffinity(2) system call. The affinity of a thread can be altered with one of the library functions: pthread_setaffinity_np(3) or pthread_attr_setaffinity_np(3). On SGI systems, dplace binds a process to a set of CPUs. [4]
In computer science, The System Contention Scope [1] is one of two thread-scheduling schemes used in operating systems.This scheme is used by the kernel to decide which kernel-level thread to schedule onto a CPU, wherein all threads (as opposed to only user-level threads, as in the Process Contention Scope scheme) in the system compete for the CPU. [2]
A task (i.e., a synonym for thread) is the minimal entity that Linux can schedule. However, it can also manage groups of threads, whole multi-threaded processes, and even all the processes of a given user. This design leads to the concept of schedulable entities, where tasks are grouped and managed by the scheduler as a whole.
Context switching itself has a cost in performance, due to running the task scheduler, TLB flushes, and indirectly due to sharing the CPU cache between multiple tasks. [7] Switching between threads of a single process can be faster than between two separate processes because threads share the same virtual memory maps, so a TLB flush is not ...
Multiple threads can interfere with each other when sharing hardware resources such as caches or translation lookaside buffers (TLBs). As a result, execution times of a single thread are not improved and can be degraded, even when only one thread is executing, due to lower frequencies or additional pipeline stages that are necessary to accommodate thread-switching hardware.
Threads created by the library (via pthread_create) correspond one-to-one with schedulable entities in the kernel (processes, in the Linux case). [4]: 226 This is the simplest of the three threading models (1:1, N:1, and M:N). [4]: 215–216 New threads are created with the clone() system call called through the
Linux also calls the threads of this process idle tasks. [2] In some APIs, PID 0 is also used as a special value that always refers to the calling thread, process, or process group. [3] [4] Process ID 1 is usually the init process primarily responsible for starting and shutting down the system. Originally, process ID 1 was not specifically ...
An affinity mask is a bit mask indicating what processor(s) a thread or process should be run on by the scheduler of an operating system. [1] Setting the affinity mask for certain processes running under Windows can be useful as there are several system processes (especially on domain controllers) that are restricted to the first CPU / Core.