Add cpuset, an api for thread to cpu binding and cpu resource grouping

and assignment.
 - Add a reference to a struct cpuset in each thread that is inherited from
   the thread that created it.
 - Release the reference when the thread is destroyed.
 - Add prototypes for syscalls and macros for manipulating cpusets in
   sys/cpuset.h
 - Add syscalls to create, get, and set new numbered cpusets:
   cpuset(), cpuset_{get,set}id()
 - Add syscalls for getting and setting affinity masks for cpusets or
   individual threads: cpuid_{get,set}affinity()
 - Add types for the 'level' and 'which' parameters for the cpuset.  This
   will permit expansion of the api to cover cpu masks for other objects
   identifiable with an id_t integer.  For example, IRQs and Jails may be
   coming soon.
 - The root set 0 contains all valid cpus.  All thread initially belong to
   cpuset 1.  This permits migrating all threads off of certain cpus to
   reserve them for special applications.

Sponsored by:	Nokia
Discussed with:	arch, rwatson, brooks, davidxu, deischen
Reviewed by:	antoine

1 files changed, 5 insertions, 1 deletions

diff --git a/sys/kern/kern_thread.c b/sys/kern/kern_thread.c
index 6f23b63..8d9f753 100644
--- a/sys/kern/kern_thread.c
+++ b/sys/kern/kern_thread.c
@@ -44,6 +44,7 @@ __FBSDID("$FreeBSD$");
 #include <sys/turnstile.h>
 #include <sys/ktr.h>
 #include <sys/umtx.h>
+#include <sys/cpuset.h>
 
 #include <security/audit/audit.h>
 
@@ -342,7 +343,8 @@ thread_alloc(void)
 void
 thread_free(struct thread *td)
 {
-
+	cpuset_rel(td->td_cpuset);
+	td->td_cpuset = NULL;
 	cpu_thread_free(td);
 	if (td->td_altkstack != 0)
 		vm_thread_dispose_altkstack(td);
@@ -527,6 +529,8 @@ thread_wait(struct proc *p)
 	/* Wait for any remaining threads to exit cpu_throw(). */
 	while (p->p_exitthreads)
 		sched_relinquish(curthread);
+	cpuset_rel(td->td_cpuset);
+	td->td_cpuset = NULL;
 	cpu_thread_clean(td);
 	crfree(td->td_ucred);
 	thread_reap();	/* check for zombie threads etc. */