freebsd-dev/sys/kern/kern_cpuset.c
Allan Jude f299c47b52 Allow cpuset_{get,set}affinity in capabilities mode
bhyve was recently sandboxed with capsicum, and needs to be able to
control the CPU sets of its vcpu threads

Reviewed by:	emaste, oshogbo, rwatson
MFC after:	2 weeks
Sponsored by:	ScaleEngine Inc.
Differential Revision:	https://reviews.freebsd.org/D10170
2017-05-24 00:58:30 +00:00

1350 lines
32 KiB
C

/*-
* Copyright (c) 2008, Jeffrey Roberson <jeff@freebsd.org>
* All rights reserved.
*
* Copyright (c) 2008 Nokia Corporation
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice unmodified, this list of conditions, and the following
* disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "opt_ddb.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/sysproto.h>
#include <sys/jail.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/mutex.h>
#include <sys/priv.h>
#include <sys/proc.h>
#include <sys/refcount.h>
#include <sys/sched.h>
#include <sys/smp.h>
#include <sys/syscallsubr.h>
#include <sys/capsicum.h>
#include <sys/cpuset.h>
#include <sys/sx.h>
#include <sys/queue.h>
#include <sys/libkern.h>
#include <sys/limits.h>
#include <sys/bus.h>
#include <sys/interrupt.h>
#include <vm/uma.h>
#include <vm/vm.h>
#include <vm/vm_page.h>
#include <vm/vm_param.h>
#ifdef DDB
#include <ddb/ddb.h>
#endif /* DDB */
/*
* cpusets provide a mechanism for creating and manipulating sets of
* processors for the purpose of constraining the scheduling of threads to
* specific processors.
*
* Each process belongs to an identified set, by default this is set 1. Each
* thread may further restrict the cpus it may run on to a subset of this
* named set. This creates an anonymous set which other threads and processes
* may not join by number.
*
* The named set is referred to herein as the 'base' set to avoid ambiguity.
* This set is usually a child of a 'root' set while the anonymous set may
* simply be referred to as a mask. In the syscall api these are referred to
* as the ROOT, CPUSET, and MASK levels where CPUSET is called 'base' here.
*
* Threads inherit their set from their creator whether it be anonymous or
* not. This means that anonymous sets are immutable because they may be
* shared. To modify an anonymous set a new set is created with the desired
* mask and the same parent as the existing anonymous set. This gives the
* illusion of each thread having a private mask.
*
* Via the syscall apis a user may ask to retrieve or modify the root, base,
* or mask that is discovered via a pid, tid, or setid. Modifying a set
* modifies all numbered and anonymous child sets to comply with the new mask.
* Modifying a pid or tid's mask applies only to that tid but must still
* exist within the assigned parent set.
*
* A thread may not be assigned to a group separate from other threads in
* the process. This is to remove ambiguity when the setid is queried with
* a pid argument. There is no other technical limitation.
*
* This somewhat complex arrangement is intended to make it easy for
* applications to query available processors and bind their threads to
* specific processors while also allowing administrators to dynamically
* reprovision by changing sets which apply to groups of processes.
*
* A simple application should not concern itself with sets at all and
* rather apply masks to its own threads via CPU_WHICH_TID and a -1 id
* meaning 'curthread'. It may query available cpus for that tid with a
* getaffinity call using (CPU_LEVEL_CPUSET, CPU_WHICH_PID, -1, ...).
*/
static uma_zone_t cpuset_zone;
static struct mtx cpuset_lock;
static struct setlist cpuset_ids;
static struct unrhdr *cpuset_unr;
static struct cpuset *cpuset_zero, *cpuset_default;
/* Return the size of cpuset_t at the kernel level */
SYSCTL_INT(_kern_sched, OID_AUTO, cpusetsize, CTLFLAG_RD | CTLFLAG_CAPRD,
SYSCTL_NULL_INT_PTR, sizeof(cpuset_t), "sizeof(cpuset_t)");
cpuset_t *cpuset_root;
cpuset_t cpuset_domain[MAXMEMDOM];
/*
* Acquire a reference to a cpuset, all pointers must be tracked with refs.
*/
struct cpuset *
cpuset_ref(struct cpuset *set)
{
refcount_acquire(&set->cs_ref);
return (set);
}
/*
* Walks up the tree from 'set' to find the root. Returns the root
* referenced.
*/
static struct cpuset *
cpuset_refroot(struct cpuset *set)
{
for (; set->cs_parent != NULL; set = set->cs_parent)
if (set->cs_flags & CPU_SET_ROOT)
break;
cpuset_ref(set);
return (set);
}
/*
* Find the first non-anonymous set starting from 'set'. Returns this set
* referenced. May return the passed in set with an extra ref if it is
* not anonymous.
*/
static struct cpuset *
cpuset_refbase(struct cpuset *set)
{
if (set->cs_id == CPUSET_INVALID)
set = set->cs_parent;
cpuset_ref(set);
return (set);
}
/*
* Release a reference in a context where it is safe to allocate.
*/
void
cpuset_rel(struct cpuset *set)
{
cpusetid_t id;
if (refcount_release(&set->cs_ref) == 0)
return;
mtx_lock_spin(&cpuset_lock);
LIST_REMOVE(set, cs_siblings);
id = set->cs_id;
if (id != CPUSET_INVALID)
LIST_REMOVE(set, cs_link);
mtx_unlock_spin(&cpuset_lock);
cpuset_rel(set->cs_parent);
uma_zfree(cpuset_zone, set);
if (id != CPUSET_INVALID)
free_unr(cpuset_unr, id);
}
/*
* Deferred release must be used when in a context that is not safe to
* allocate/free. This places any unreferenced sets on the list 'head'.
*/
static void
cpuset_rel_defer(struct setlist *head, struct cpuset *set)
{
if (refcount_release(&set->cs_ref) == 0)
return;
mtx_lock_spin(&cpuset_lock);
LIST_REMOVE(set, cs_siblings);
if (set->cs_id != CPUSET_INVALID)
LIST_REMOVE(set, cs_link);
LIST_INSERT_HEAD(head, set, cs_link);
mtx_unlock_spin(&cpuset_lock);
}
/*
* Complete a deferred release. Removes the set from the list provided to
* cpuset_rel_defer.
*/
static void
cpuset_rel_complete(struct cpuset *set)
{
LIST_REMOVE(set, cs_link);
cpuset_rel(set->cs_parent);
uma_zfree(cpuset_zone, set);
}
/*
* Find a set based on an id. Returns it with a ref.
*/
static struct cpuset *
cpuset_lookup(cpusetid_t setid, struct thread *td)
{
struct cpuset *set;
if (setid == CPUSET_INVALID)
return (NULL);
mtx_lock_spin(&cpuset_lock);
LIST_FOREACH(set, &cpuset_ids, cs_link)
if (set->cs_id == setid)
break;
if (set)
cpuset_ref(set);
mtx_unlock_spin(&cpuset_lock);
KASSERT(td != NULL, ("[%s:%d] td is NULL", __func__, __LINE__));
if (set != NULL && jailed(td->td_ucred)) {
struct cpuset *jset, *tset;
jset = td->td_ucred->cr_prison->pr_cpuset;
for (tset = set; tset != NULL; tset = tset->cs_parent)
if (tset == jset)
break;
if (tset == NULL) {
cpuset_rel(set);
set = NULL;
}
}
return (set);
}
/*
* Create a set in the space provided in 'set' with the provided parameters.
* The set is returned with a single ref. May return EDEADLK if the set
* will have no valid cpu based on restrictions from the parent.
*/
static int
_cpuset_create(struct cpuset *set, struct cpuset *parent, const cpuset_t *mask,
cpusetid_t id)
{
if (!CPU_OVERLAP(&parent->cs_mask, mask))
return (EDEADLK);
CPU_COPY(mask, &set->cs_mask);
LIST_INIT(&set->cs_children);
refcount_init(&set->cs_ref, 1);
set->cs_flags = 0;
mtx_lock_spin(&cpuset_lock);
CPU_AND(&set->cs_mask, &parent->cs_mask);
set->cs_id = id;
set->cs_parent = cpuset_ref(parent);
LIST_INSERT_HEAD(&parent->cs_children, set, cs_siblings);
if (set->cs_id != CPUSET_INVALID)
LIST_INSERT_HEAD(&cpuset_ids, set, cs_link);
mtx_unlock_spin(&cpuset_lock);
return (0);
}
/*
* Create a new non-anonymous set with the requested parent and mask. May
* return failures if the mask is invalid or a new number can not be
* allocated.
*/
static int
cpuset_create(struct cpuset **setp, struct cpuset *parent, const cpuset_t *mask)
{
struct cpuset *set;
cpusetid_t id;
int error;
id = alloc_unr(cpuset_unr);
if (id == -1)
return (ENFILE);
*setp = set = uma_zalloc(cpuset_zone, M_WAITOK);
error = _cpuset_create(set, parent, mask, id);
if (error == 0)
return (0);
free_unr(cpuset_unr, id);
uma_zfree(cpuset_zone, set);
return (error);
}
/*
* Recursively check for errors that would occur from applying mask to
* the tree of sets starting at 'set'. Checks for sets that would become
* empty as well as RDONLY flags.
*/
static int
cpuset_testupdate(struct cpuset *set, cpuset_t *mask, int check_mask)
{
struct cpuset *nset;
cpuset_t newmask;
int error;
mtx_assert(&cpuset_lock, MA_OWNED);
if (set->cs_flags & CPU_SET_RDONLY)
return (EPERM);
if (check_mask) {
if (!CPU_OVERLAP(&set->cs_mask, mask))
return (EDEADLK);
CPU_COPY(&set->cs_mask, &newmask);
CPU_AND(&newmask, mask);
} else
CPU_COPY(mask, &newmask);
error = 0;
LIST_FOREACH(nset, &set->cs_children, cs_siblings)
if ((error = cpuset_testupdate(nset, &newmask, 1)) != 0)
break;
return (error);
}
/*
* Applies the mask 'mask' without checking for empty sets or permissions.
*/
static void
cpuset_update(struct cpuset *set, cpuset_t *mask)
{
struct cpuset *nset;
mtx_assert(&cpuset_lock, MA_OWNED);
CPU_AND(&set->cs_mask, mask);
LIST_FOREACH(nset, &set->cs_children, cs_siblings)
cpuset_update(nset, &set->cs_mask);
return;
}
/*
* Modify the set 'set' to use a copy of the mask provided. Apply this new
* mask to restrict all children in the tree. Checks for validity before
* applying the changes.
*/
static int
cpuset_modify(struct cpuset *set, cpuset_t *mask)
{
struct cpuset *root;
int error;
error = priv_check(curthread, PRIV_SCHED_CPUSET);
if (error)
return (error);
/*
* In case we are called from within the jail
* we do not allow modifying the dedicated root
* cpuset of the jail but may still allow to
* change child sets.
*/
if (jailed(curthread->td_ucred) &&
set->cs_flags & CPU_SET_ROOT)
return (EPERM);
/*
* Verify that we have access to this set of
* cpus.
*/
root = set->cs_parent;
if (root && !CPU_SUBSET(&root->cs_mask, mask))
return (EINVAL);
mtx_lock_spin(&cpuset_lock);
error = cpuset_testupdate(set, mask, 0);
if (error)
goto out;
CPU_COPY(mask, &set->cs_mask);
cpuset_update(set, mask);
out:
mtx_unlock_spin(&cpuset_lock);
return (error);
}
/*
* Resolve the 'which' parameter of several cpuset apis.
*
* For WHICH_PID and WHICH_TID return a locked proc and valid proc/tid. Also
* checks for permission via p_cansched().
*
* For WHICH_SET returns a valid set with a new reference.
*
* -1 may be supplied for any argument to mean the current proc/thread or
* the base set of the current thread. May fail with ESRCH/EPERM.
*/
int
cpuset_which(cpuwhich_t which, id_t id, struct proc **pp, struct thread **tdp,
struct cpuset **setp)
{
struct cpuset *set;
struct thread *td;
struct proc *p;
int error;
*pp = p = NULL;
*tdp = td = NULL;
*setp = set = NULL;
switch (which) {
case CPU_WHICH_PID:
if (id == -1) {
PROC_LOCK(curproc);
p = curproc;
break;
}
if ((p = pfind(id)) == NULL)
return (ESRCH);
break;
case CPU_WHICH_TID:
if (id == -1) {
PROC_LOCK(curproc);
p = curproc;
td = curthread;
break;
}
td = tdfind(id, -1);
if (td == NULL)
return (ESRCH);
p = td->td_proc;
break;
case CPU_WHICH_CPUSET:
if (id == -1) {
thread_lock(curthread);
set = cpuset_refbase(curthread->td_cpuset);
thread_unlock(curthread);
} else
set = cpuset_lookup(id, curthread);
if (set) {
*setp = set;
return (0);
}
return (ESRCH);
case CPU_WHICH_JAIL:
{
/* Find `set' for prison with given id. */
struct prison *pr;
sx_slock(&allprison_lock);
pr = prison_find_child(curthread->td_ucred->cr_prison, id);
sx_sunlock(&allprison_lock);
if (pr == NULL)
return (ESRCH);
cpuset_ref(pr->pr_cpuset);
*setp = pr->pr_cpuset;
mtx_unlock(&pr->pr_mtx);
return (0);
}
case CPU_WHICH_IRQ:
case CPU_WHICH_DOMAIN:
return (0);
default:
return (EINVAL);
}
error = p_cansched(curthread, p);
if (error) {
PROC_UNLOCK(p);
return (error);
}
if (td == NULL)
td = FIRST_THREAD_IN_PROC(p);
*pp = p;
*tdp = td;
return (0);
}
/*
* Create an anonymous set with the provided mask in the space provided by
* 'fset'. If the passed in set is anonymous we use its parent otherwise
* the new set is a child of 'set'.
*/
static int
cpuset_shadow(struct cpuset *set, struct cpuset *fset, const cpuset_t *mask)
{
struct cpuset *parent;
if (set->cs_id == CPUSET_INVALID)
parent = set->cs_parent;
else
parent = set;
if (!CPU_SUBSET(&parent->cs_mask, mask))
return (EDEADLK);
return (_cpuset_create(fset, parent, mask, CPUSET_INVALID));
}
/*
* Handle two cases for replacing the base set or mask of an entire process.
*
* 1) Set is non-null and mask is null. This reparents all anonymous sets
* to the provided set and replaces all non-anonymous td_cpusets with the
* provided set.
* 2) Mask is non-null and set is null. This replaces or creates anonymous
* sets for every thread with the existing base as a parent.
*
* This is overly complicated because we can't allocate while holding a
* spinlock and spinlocks must be held while changing and examining thread
* state.
*/
static int
cpuset_setproc(pid_t pid, struct cpuset *set, cpuset_t *mask)
{
struct setlist freelist;
struct setlist droplist;
struct cpuset *tdset;
struct cpuset *nset;
struct thread *td;
struct proc *p;
int threads;
int nfree;
int error;
/*
* The algorithm requires two passes due to locking considerations.
*
* 1) Lookup the process and acquire the locks in the required order.
* 2) If enough cpusets have not been allocated release the locks and
* allocate them. Loop.
*/
LIST_INIT(&freelist);
LIST_INIT(&droplist);
nfree = 0;
for (;;) {
error = cpuset_which(CPU_WHICH_PID, pid, &p, &td, &nset);
if (error)
goto out;
if (nfree >= p->p_numthreads)
break;
threads = p->p_numthreads;
PROC_UNLOCK(p);
for (; nfree < threads; nfree++) {
nset = uma_zalloc(cpuset_zone, M_WAITOK);
LIST_INSERT_HEAD(&freelist, nset, cs_link);
}
}
PROC_LOCK_ASSERT(p, MA_OWNED);
/*
* Now that the appropriate locks are held and we have enough cpusets,
* make sure the operation will succeed before applying changes. The
* proc lock prevents td_cpuset from changing between calls.
*/
error = 0;
FOREACH_THREAD_IN_PROC(p, td) {
thread_lock(td);
tdset = td->td_cpuset;
/*
* Verify that a new mask doesn't specify cpus outside of
* the set the thread is a member of.
*/
if (mask) {
if (tdset->cs_id == CPUSET_INVALID)
tdset = tdset->cs_parent;
if (!CPU_SUBSET(&tdset->cs_mask, mask))
error = EDEADLK;
/*
* Verify that a new set won't leave an existing thread
* mask without a cpu to run on. It can, however, restrict
* the set.
*/
} else if (tdset->cs_id == CPUSET_INVALID) {
if (!CPU_OVERLAP(&set->cs_mask, &tdset->cs_mask))
error = EDEADLK;
}
thread_unlock(td);
if (error)
goto unlock_out;
}
/*
* Replace each thread's cpuset while using deferred release. We
* must do this because the thread lock must be held while operating
* on the thread and this limits the type of operations allowed.
*/
FOREACH_THREAD_IN_PROC(p, td) {
thread_lock(td);
/*
* If we presently have an anonymous set or are applying a
* mask we must create an anonymous shadow set. That is
* either parented to our existing base or the supplied set.
*
* If we have a base set with no anonymous shadow we simply
* replace it outright.
*/
tdset = td->td_cpuset;
if (tdset->cs_id == CPUSET_INVALID || mask) {
nset = LIST_FIRST(&freelist);
LIST_REMOVE(nset, cs_link);
if (mask)
error = cpuset_shadow(tdset, nset, mask);
else
error = _cpuset_create(nset, set,
&tdset->cs_mask, CPUSET_INVALID);
if (error) {
LIST_INSERT_HEAD(&freelist, nset, cs_link);
thread_unlock(td);
break;
}
} else
nset = cpuset_ref(set);
cpuset_rel_defer(&droplist, tdset);
td->td_cpuset = nset;
sched_affinity(td);
thread_unlock(td);
}
unlock_out:
PROC_UNLOCK(p);
out:
while ((nset = LIST_FIRST(&droplist)) != NULL)
cpuset_rel_complete(nset);
while ((nset = LIST_FIRST(&freelist)) != NULL) {
LIST_REMOVE(nset, cs_link);
uma_zfree(cpuset_zone, nset);
}
return (error);
}
/*
* Return a string representing a valid layout for a cpuset_t object.
* It expects an incoming buffer at least sized as CPUSETBUFSIZ.
*/
char *
cpusetobj_strprint(char *buf, const cpuset_t *set)
{
char *tbuf;
size_t i, bytesp, bufsiz;
tbuf = buf;
bytesp = 0;
bufsiz = CPUSETBUFSIZ;
for (i = 0; i < (_NCPUWORDS - 1); i++) {
bytesp = snprintf(tbuf, bufsiz, "%lx,", set->__bits[i]);
bufsiz -= bytesp;
tbuf += bytesp;
}
snprintf(tbuf, bufsiz, "%lx", set->__bits[_NCPUWORDS - 1]);
return (buf);
}
/*
* Build a valid cpuset_t object from a string representation.
* It expects an incoming buffer at least sized as CPUSETBUFSIZ.
*/
int
cpusetobj_strscan(cpuset_t *set, const char *buf)
{
u_int nwords;
int i, ret;
if (strlen(buf) > CPUSETBUFSIZ - 1)
return (-1);
/* Allow to pass a shorter version of the mask when necessary. */
nwords = 1;
for (i = 0; buf[i] != '\0'; i++)
if (buf[i] == ',')
nwords++;
if (nwords > _NCPUWORDS)
return (-1);
CPU_ZERO(set);
for (i = 0; i < (nwords - 1); i++) {
ret = sscanf(buf, "%lx,", &set->__bits[i]);
if (ret == 0 || ret == -1)
return (-1);
buf = strstr(buf, ",");
if (buf == NULL)
return (-1);
buf++;
}
ret = sscanf(buf, "%lx", &set->__bits[nwords - 1]);
if (ret == 0 || ret == -1)
return (-1);
return (0);
}
/*
* Apply an anonymous mask to a single thread.
*/
int
cpuset_setthread(lwpid_t id, cpuset_t *mask)
{
struct cpuset *nset;
struct cpuset *set;
struct thread *td;
struct proc *p;
int error;
nset = uma_zalloc(cpuset_zone, M_WAITOK);
error = cpuset_which(CPU_WHICH_TID, id, &p, &td, &set);
if (error)
goto out;
set = NULL;
thread_lock(td);
error = cpuset_shadow(td->td_cpuset, nset, mask);
if (error == 0) {
set = td->td_cpuset;
td->td_cpuset = nset;
sched_affinity(td);
nset = NULL;
}
thread_unlock(td);
PROC_UNLOCK(p);
if (set)
cpuset_rel(set);
out:
if (nset)
uma_zfree(cpuset_zone, nset);
return (error);
}
/*
* Apply new cpumask to the ithread.
*/
int
cpuset_setithread(lwpid_t id, int cpu)
{
struct cpuset *nset, *rset;
struct cpuset *parent, *old_set;
struct thread *td;
struct proc *p;
cpusetid_t cs_id;
cpuset_t mask;
int error;
nset = uma_zalloc(cpuset_zone, M_WAITOK);
rset = uma_zalloc(cpuset_zone, M_WAITOK);
cs_id = CPUSET_INVALID;
CPU_ZERO(&mask);
if (cpu == NOCPU)
CPU_COPY(cpuset_root, &mask);
else
CPU_SET(cpu, &mask);
error = cpuset_which(CPU_WHICH_TID, id, &p, &td, &old_set);
if (error != 0 || ((cs_id = alloc_unr(cpuset_unr)) == CPUSET_INVALID))
goto out;
/* cpuset_which() returns with PROC_LOCK held. */
old_set = td->td_cpuset;
if (cpu == NOCPU) {
/*
* roll back to default set. We're not using cpuset_shadow()
* here because we can fail CPU_SUBSET() check. This can happen
* if default set does not contain all CPUs.
*/
error = _cpuset_create(nset, cpuset_default, &mask,
CPUSET_INVALID);
goto applyset;
}
if (old_set->cs_id == 1 || (old_set->cs_id == CPUSET_INVALID &&
old_set->cs_parent->cs_id == 1)) {
/*
* Current set is either default (1) or
* shadowed version of default set.
*
* Allocate new root set to be able to shadow it
* with any mask.
*/
error = _cpuset_create(rset, cpuset_zero,
&cpuset_zero->cs_mask, cs_id);
if (error != 0) {
PROC_UNLOCK(p);
goto out;
}
rset->cs_flags |= CPU_SET_ROOT;
parent = rset;
rset = NULL;
cs_id = CPUSET_INVALID;
} else {
/* Assume existing set was already allocated by previous call */
parent = old_set;
old_set = NULL;
}
error = cpuset_shadow(parent, nset, &mask);
applyset:
if (error == 0) {
thread_lock(td);
td->td_cpuset = nset;
sched_affinity(td);
thread_unlock(td);
nset = NULL;
} else
old_set = NULL;
PROC_UNLOCK(p);
if (old_set != NULL)
cpuset_rel(old_set);
out:
if (nset != NULL)
uma_zfree(cpuset_zone, nset);
if (rset != NULL)
uma_zfree(cpuset_zone, rset);
if (cs_id != CPUSET_INVALID)
free_unr(cpuset_unr, cs_id);
return (error);
}
/*
* Creates system-wide cpusets and the cpuset for thread0 including two
* sets:
*
* 0 - The root set which should represent all valid processors in the
* system. It is initially created with a mask of all processors
* because we don't know what processors are valid until cpuset_init()
* runs. This set is immutable.
* 1 - The default set which all processes are a member of until changed.
* This allows an administrator to move all threads off of given cpus to
* dedicate them to high priority tasks or save power etc.
*/
struct cpuset *
cpuset_thread0(void)
{
struct cpuset *set;
int error, i;
cpuset_zone = uma_zcreate("cpuset", sizeof(struct cpuset), NULL, NULL,
NULL, NULL, UMA_ALIGN_PTR, 0);
mtx_init(&cpuset_lock, "cpuset", NULL, MTX_SPIN | MTX_RECURSE);
/*
* Create the root system set for the whole machine. Doesn't use
* cpuset_create() due to NULL parent.
*/
set = uma_zalloc(cpuset_zone, M_WAITOK | M_ZERO);
CPU_FILL(&set->cs_mask);
LIST_INIT(&set->cs_children);
LIST_INSERT_HEAD(&cpuset_ids, set, cs_link);
set->cs_ref = 1;
set->cs_flags = CPU_SET_ROOT;
cpuset_zero = set;
cpuset_root = &set->cs_mask;
/*
* Now derive a default, modifiable set from that to give out.
*/
set = uma_zalloc(cpuset_zone, M_WAITOK);
error = _cpuset_create(set, cpuset_zero, &cpuset_zero->cs_mask, 1);
KASSERT(error == 0, ("Error creating default set: %d\n", error));
cpuset_default = set;
/*
* Initialize the unit allocator. 0 and 1 are allocated above.
*/
cpuset_unr = new_unrhdr(2, INT_MAX, NULL);
/*
* If MD code has not initialized per-domain cpusets, place all
* CPUs in domain 0.
*/
for (i = 0; i < MAXMEMDOM; i++)
if (!CPU_EMPTY(&cpuset_domain[i]))
goto domains_set;
CPU_COPY(&all_cpus, &cpuset_domain[0]);
domains_set:
return (set);
}
/*
* Create a cpuset, which would be cpuset_create() but
* mark the new 'set' as root.
*
* We are not going to reparent the td to it. Use cpuset_setproc_update_set()
* for that.
*
* In case of no error, returns the set in *setp locked with a reference.
*/
int
cpuset_create_root(struct prison *pr, struct cpuset **setp)
{
struct cpuset *set;
int error;
KASSERT(pr != NULL, ("[%s:%d] invalid pr", __func__, __LINE__));
KASSERT(setp != NULL, ("[%s:%d] invalid setp", __func__, __LINE__));
error = cpuset_create(setp, pr->pr_cpuset, &pr->pr_cpuset->cs_mask);
if (error)
return (error);
KASSERT(*setp != NULL, ("[%s:%d] cpuset_create returned invalid data",
__func__, __LINE__));
/* Mark the set as root. */
set = *setp;
set->cs_flags |= CPU_SET_ROOT;
return (0);
}
int
cpuset_setproc_update_set(struct proc *p, struct cpuset *set)
{
int error;
KASSERT(p != NULL, ("[%s:%d] invalid proc", __func__, __LINE__));
KASSERT(set != NULL, ("[%s:%d] invalid set", __func__, __LINE__));
cpuset_ref(set);
error = cpuset_setproc(p->p_pid, set, NULL);
if (error)
return (error);
cpuset_rel(set);
return (0);
}
/*
* This is called once the final set of system cpus is known. Modifies
* the root set and all children and mark the root read-only.
*/
static void
cpuset_init(void *arg)
{
cpuset_t mask;
mask = all_cpus;
if (cpuset_modify(cpuset_zero, &mask))
panic("Can't set initial cpuset mask.\n");
cpuset_zero->cs_flags |= CPU_SET_RDONLY;
}
SYSINIT(cpuset, SI_SUB_SMP, SI_ORDER_ANY, cpuset_init, NULL);
#ifndef _SYS_SYSPROTO_H_
struct cpuset_args {
cpusetid_t *setid;
};
#endif
int
sys_cpuset(struct thread *td, struct cpuset_args *uap)
{
struct cpuset *root;
struct cpuset *set;
int error;
thread_lock(td);
root = cpuset_refroot(td->td_cpuset);
thread_unlock(td);
error = cpuset_create(&set, root, &root->cs_mask);
cpuset_rel(root);
if (error)
return (error);
error = copyout(&set->cs_id, uap->setid, sizeof(set->cs_id));
if (error == 0)
error = cpuset_setproc(-1, set, NULL);
cpuset_rel(set);
return (error);
}
#ifndef _SYS_SYSPROTO_H_
struct cpuset_setid_args {
cpuwhich_t which;
id_t id;
cpusetid_t setid;
};
#endif
int
sys_cpuset_setid(struct thread *td, struct cpuset_setid_args *uap)
{
return (kern_cpuset_setid(td, uap->which, uap->id, uap->setid));
}
int
kern_cpuset_setid(struct thread *td, cpuwhich_t which,
id_t id, cpusetid_t setid)
{
struct cpuset *set;
int error;
/*
* Presently we only support per-process sets.
*/
if (which != CPU_WHICH_PID)
return (EINVAL);
set = cpuset_lookup(setid, td);
if (set == NULL)
return (ESRCH);
error = cpuset_setproc(id, set, NULL);
cpuset_rel(set);
return (error);
}
#ifndef _SYS_SYSPROTO_H_
struct cpuset_getid_args {
cpulevel_t level;
cpuwhich_t which;
id_t id;
cpusetid_t *setid;
};
#endif
int
sys_cpuset_getid(struct thread *td, struct cpuset_getid_args *uap)
{
return (kern_cpuset_getid(td, uap->level, uap->which, uap->id,
uap->setid));
}
int
kern_cpuset_getid(struct thread *td, cpulevel_t level, cpuwhich_t which,
id_t id, cpusetid_t *setid)
{
struct cpuset *nset;
struct cpuset *set;
struct thread *ttd;
struct proc *p;
cpusetid_t tmpid;
int error;
if (level == CPU_LEVEL_WHICH && which != CPU_WHICH_CPUSET)
return (EINVAL);
error = cpuset_which(which, id, &p, &ttd, &set);
if (error)
return (error);
switch (which) {
case CPU_WHICH_TID:
case CPU_WHICH_PID:
thread_lock(ttd);
set = cpuset_refbase(ttd->td_cpuset);
thread_unlock(ttd);
PROC_UNLOCK(p);
break;
case CPU_WHICH_CPUSET:
case CPU_WHICH_JAIL:
break;
case CPU_WHICH_IRQ:
case CPU_WHICH_DOMAIN:
return (EINVAL);
}
switch (level) {
case CPU_LEVEL_ROOT:
nset = cpuset_refroot(set);
cpuset_rel(set);
set = nset;
break;
case CPU_LEVEL_CPUSET:
break;
case CPU_LEVEL_WHICH:
break;
}
tmpid = set->cs_id;
cpuset_rel(set);
if (error == 0)
error = copyout(&tmpid, setid, sizeof(id));
return (error);
}
#ifndef _SYS_SYSPROTO_H_
struct cpuset_getaffinity_args {
cpulevel_t level;
cpuwhich_t which;
id_t id;
size_t cpusetsize;
cpuset_t *mask;
};
#endif
int
sys_cpuset_getaffinity(struct thread *td, struct cpuset_getaffinity_args *uap)
{
return (kern_cpuset_getaffinity(td, uap->level, uap->which,
uap->id, uap->cpusetsize, uap->mask));
}
int
kern_cpuset_getaffinity(struct thread *td, cpulevel_t level, cpuwhich_t which,
id_t id, size_t cpusetsize, cpuset_t *maskp)
{
struct thread *ttd;
struct cpuset *nset;
struct cpuset *set;
struct proc *p;
cpuset_t *mask;
int error;
size_t size;
if (cpusetsize < sizeof(cpuset_t) || cpusetsize > CPU_MAXSIZE / NBBY)
return (ERANGE);
/* In Capability mode, you can only get your own CPU set. */
if (IN_CAPABILITY_MODE(td)) {
if (level != CPU_LEVEL_WHICH)
return (ECAPMODE);
if (which != CPU_WHICH_TID && which != CPU_WHICH_PID)
return (ECAPMODE);
if (id != -1)
return (ECAPMODE);
}
size = cpusetsize;
mask = malloc(size, M_TEMP, M_WAITOK | M_ZERO);
error = cpuset_which(which, id, &p, &ttd, &set);
if (error)
goto out;
switch (level) {
case CPU_LEVEL_ROOT:
case CPU_LEVEL_CPUSET:
switch (which) {
case CPU_WHICH_TID:
case CPU_WHICH_PID:
thread_lock(ttd);
set = cpuset_ref(ttd->td_cpuset);
thread_unlock(ttd);
break;
case CPU_WHICH_CPUSET:
case CPU_WHICH_JAIL:
break;
case CPU_WHICH_IRQ:
case CPU_WHICH_INTRHANDLER:
case CPU_WHICH_ITHREAD:
case CPU_WHICH_DOMAIN:
error = EINVAL;
goto out;
}
if (level == CPU_LEVEL_ROOT)
nset = cpuset_refroot(set);
else
nset = cpuset_refbase(set);
CPU_COPY(&nset->cs_mask, mask);
cpuset_rel(nset);
break;
case CPU_LEVEL_WHICH:
switch (which) {
case CPU_WHICH_TID:
thread_lock(ttd);
CPU_COPY(&ttd->td_cpuset->cs_mask, mask);
thread_unlock(ttd);
break;
case CPU_WHICH_PID:
FOREACH_THREAD_IN_PROC(p, ttd) {
thread_lock(ttd);
CPU_OR(mask, &ttd->td_cpuset->cs_mask);
thread_unlock(ttd);
}
break;
case CPU_WHICH_CPUSET:
case CPU_WHICH_JAIL:
CPU_COPY(&set->cs_mask, mask);
break;
case CPU_WHICH_IRQ:
case CPU_WHICH_INTRHANDLER:
case CPU_WHICH_ITHREAD:
error = intr_getaffinity(id, which, mask);
break;
case CPU_WHICH_DOMAIN:
if (id < 0 || id >= MAXMEMDOM)
error = ESRCH;
else
CPU_COPY(&cpuset_domain[id], mask);
break;
}
break;
default:
error = EINVAL;
break;
}
if (set)
cpuset_rel(set);
if (p)
PROC_UNLOCK(p);
if (error == 0)
error = copyout(mask, maskp, size);
out:
free(mask, M_TEMP);
return (error);
}
#ifndef _SYS_SYSPROTO_H_
struct cpuset_setaffinity_args {
cpulevel_t level;
cpuwhich_t which;
id_t id;
size_t cpusetsize;
const cpuset_t *mask;
};
#endif
int
sys_cpuset_setaffinity(struct thread *td, struct cpuset_setaffinity_args *uap)
{
return (kern_cpuset_setaffinity(td, uap->level, uap->which,
uap->id, uap->cpusetsize, uap->mask));
}
int
kern_cpuset_setaffinity(struct thread *td, cpulevel_t level, cpuwhich_t which,
id_t id, size_t cpusetsize, const cpuset_t *maskp)
{
struct cpuset *nset;
struct cpuset *set;
struct thread *ttd;
struct proc *p;
cpuset_t *mask;
int error;
if (cpusetsize < sizeof(cpuset_t) || cpusetsize > CPU_MAXSIZE / NBBY)
return (ERANGE);
/* In Capability mode, you can only set your own CPU set. */
if (IN_CAPABILITY_MODE(td)) {
if (level != CPU_LEVEL_WHICH)
return (ECAPMODE);
if (which != CPU_WHICH_TID && which != CPU_WHICH_PID)
return (ECAPMODE);
if (id != -1)
return (ECAPMODE);
}
mask = malloc(cpusetsize, M_TEMP, M_WAITOK | M_ZERO);
error = copyin(maskp, mask, cpusetsize);
if (error)
goto out;
/*
* Verify that no high bits are set.
*/
if (cpusetsize > sizeof(cpuset_t)) {
char *end;
char *cp;
end = cp = (char *)&mask->__bits;
end += cpusetsize;
cp += sizeof(cpuset_t);
while (cp != end)
if (*cp++ != 0) {
error = EINVAL;
goto out;
}
}
switch (level) {
case CPU_LEVEL_ROOT:
case CPU_LEVEL_CPUSET:
error = cpuset_which(which, id, &p, &ttd, &set);
if (error)
break;
switch (which) {
case CPU_WHICH_TID:
case CPU_WHICH_PID:
thread_lock(ttd);
set = cpuset_ref(ttd->td_cpuset);
thread_unlock(ttd);
PROC_UNLOCK(p);
break;
case CPU_WHICH_CPUSET:
case CPU_WHICH_JAIL:
break;
case CPU_WHICH_IRQ:
case CPU_WHICH_INTRHANDLER:
case CPU_WHICH_ITHREAD:
case CPU_WHICH_DOMAIN:
error = EINVAL;
goto out;
}
if (level == CPU_LEVEL_ROOT)
nset = cpuset_refroot(set);
else
nset = cpuset_refbase(set);
error = cpuset_modify(nset, mask);
cpuset_rel(nset);
cpuset_rel(set);
break;
case CPU_LEVEL_WHICH:
switch (which) {
case CPU_WHICH_TID:
error = cpuset_setthread(id, mask);
break;
case CPU_WHICH_PID:
error = cpuset_setproc(id, NULL, mask);
break;
case CPU_WHICH_CPUSET:
case CPU_WHICH_JAIL:
error = cpuset_which(which, id, &p, &ttd, &set);
if (error == 0) {
error = cpuset_modify(set, mask);
cpuset_rel(set);
}
break;
case CPU_WHICH_IRQ:
case CPU_WHICH_INTRHANDLER:
case CPU_WHICH_ITHREAD:
error = intr_setaffinity(id, which, mask);
break;
default:
error = EINVAL;
break;
}
break;
default:
error = EINVAL;
break;
}
out:
free(mask, M_TEMP);
return (error);
}
#ifdef DDB
void
ddb_display_cpuset(const cpuset_t *set)
{
int cpu, once;
for (once = 0, cpu = 0; cpu < CPU_SETSIZE; cpu++) {
if (CPU_ISSET(cpu, set)) {
if (once == 0) {
db_printf("%d", cpu);
once = 1;
} else
db_printf(",%d", cpu);
}
}
if (once == 0)
db_printf("<none>");
}
DB_SHOW_COMMAND(cpusets, db_show_cpusets)
{
struct cpuset *set;
LIST_FOREACH(set, &cpuset_ids, cs_link) {
db_printf("set=%p id=%-6u ref=%-6d flags=0x%04x parent id=%d\n",
set, set->cs_id, set->cs_ref, set->cs_flags,
(set->cs_parent != NULL) ? set->cs_parent->cs_id : 0);
db_printf(" mask=");
ddb_display_cpuset(&set->cs_mask);
db_printf("\n");
if (db_pager_quit)
break;
}
}
#endif /* DDB */