Editing Processor affinity (section)

==Specific operating systems==
On [[Linux]], the CPU affinity of a process can be altered with the taskset(1) program<ref>{{man|1|taskset|Linux}}</ref> 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 [[Silicon Graphics|SGI]] systems, [https://web.archive.org/web/20070701091047/http://techpubs.sgi.com/library/tpl/cgi-bin/getdoc.cgi?coll=linux&db=man&fname=%2Fusr%2Fshare%2Fcatman%2Fman1%2Fdplace.1.html dplace] binds a process to a set of CPUs.<ref>[http://techpubs.sgi.com/library/tpl/cgi-bin/getdoc.cgi?coll=linux&db=man&fname=/usr/share/catman/man1/dplace.1.html dplace.1] {{webarchive|url=https://web.archive.org/web/20070701091047/http://techpubs.sgi.com/library/tpl/cgi-bin/getdoc.cgi?coll=linux&db=man&fname=%2Fusr%2Fshare%2Fcatman%2Fman1%2Fdplace.1.html |date=2007-07-01 }} - From ''[http://www.sgi.com sgi.com]''. Accessed 2007-07-06.</ref>

On [[DragonFly BSD]] 1.9 (2007) and later versions, usched_set system call can be used to control the affinity of a process.<ref>{{cite web |url= http://mdoc.su/d/usched_set.2 |title= <code>usched_set(2)</code> — setting up a proc's usched |work= DragonFly System Calls Manual |publisher= [[DragonFly BSD]] |access-date= 2019-07-28 }}</ref><ref>{{cite web |url= http://bxr.su/d/sys/kern/kern_usched.c#sys_usched_set |title= <code>kern/kern_usched.c § sys_usched_set</code> |website= BSD Cross Reference |publisher= [[DragonFly BSD]] |access-date= 2019-07-28 }}</ref> On [[NetBSD]] 5.0, [[FreeBSD]] 7.2, [[DragonFly BSD]] 4.7 and later versions can use pthread_setaffinity_np and pthread_getaffinity_np.<ref><code>{{URL|http://mdoc.su/n,f,d/pthread_setaffinity_np.3|pthread_setaffinity_np(3)}}</code> – [[NetBSD]], [[FreeBSD]] and [[DragonFly BSD]] Library Functions Manual</ref> In [[NetBSD]], the psrset utility<ref>{{man|8|psrset|NetBSD}}</ref> to set a thread's affinity to a certain CPU set. In [[FreeBSD]], cpuset<ref>{{man|1|cpuset|FreeBSD}}</ref> utility is used to create CPU sets and to assign processes to these sets. In [[DragonFly BSD]] 3.1 (2012) and later, usched utility can be used for assigning processes to a certain CPU set.<ref>{{cite web |url= http://mdoc.su/d/usched.8 |title= <code>usched(8)</code> — run a program with a specified userland scheduler and cpumask |work= DragonFly System Manager's Manual |publisher= [[DragonFly BSD]] |access-date= 2019-07-28 }}</ref>

On [[Windows NT]] and its successors, thread and process CPU affinities can be set separately by using SetThreadAffinityMask<ref>[http://msdn2.microsoft.com/en-us/library/ms686247(VS.85).aspx SetThreadAffinityMask] - [[MSDN Library]]</ref> and SetProcessAffinityMask<ref>[http://msdn2.microsoft.com/en-us/library/ms686223(VS.85).aspx SetProcessAffinityMask] - [[MSDN Library]]</ref> API calls or via the Task Manager interface (for process affinity only).

[[macOS]] exposes an affinity API<ref>{{cite web|url=https://developer.apple.com/library/mac/#releasenotes/Performance/RN-AffinityAPI/index.html|title=Thread Affinity API Release Notes|website=Developer.apple.com}}</ref> that provides hints to the kernel how to schedule threads according to affinity sets.

On [[Solaris (operating system)|Solaris]] it is possible to control bindings of processes and LWPs to processor using the pbind(1)<ref>[http://docs.oracle.com/cd/E23824_01/html/821-1462/pbind-1m.html pbind(1M)] - Solaris man page</ref> program. To control the affinity programmatically processor_bind(2)<ref>[http://docs.oracle.com/cd/E19109-01/tsolaris8/817-0881/6mglbsoma/index.html processor_bind(2)] - Solaris man page</ref> can be used. There are more generic interfaces available such as pset_bind(2)<ref>[http://docs.oracle.com/cd/E26502_01/html/E29032/pset-bind-2.html#REFMAN2pset-bind-2 pset_bind(2)] - Oracle Solaris 11.1 Information Library - man pages section 2</ref> or lgrp_affinity_get(3LGRP)<ref>[http://docs.oracle.com/cd/E19120-01/open.solaris/820-1691/lgroups-193/index.html lgrp_affinity_get(3LGRP)] - Memory and Thread Placement Optimization Developer's Guide</ref> using processor set and locality groups concepts.

On [[IBM AIX|AIX]] it is possible to control bindings of processes using the bindprocessor command<ref name="processor-affinity-on-aix">{{cite web|url=https://www.ibm.com/developerworks/aix/library/au-processinfinity.html|title=Processor affinity on AIX|author1=Umesh Prabhakar Gaikwad|author2=Kailas S. Zadbuke|website=[[IBM]] |date=November 16, 2006}}</ref><ref>{{cite web|url=https://www.ibm.com/support/knowledgecenter/en/ssw_aix_72/b_commands/bindprocessor.html|title=bindprocessor Command|website=IBM}}</ref> and the bindprocessor API.<ref name="processor-affinity-on-aix"/><ref>{{cite web|url=https://www.ibm.com/support/knowledgecenter/en/ssw_aix_72/b_bostechref/bindprocessor.html|title=bindprocessor Subroutine|website=IBM}}</ref>