/*-
* Copyright (c) 2015 Adrian Chadd <adrian@FreeBSD.org>.
* 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, this list of conditions and the following disclaimer,
* without modification.
* 2. Redistributions in binary form must reproduce at minimum a disclaimer
* similar to the "NO WARRANTY" disclaimer below ("Disclaimer") and any
* redistribution must be conditioned upon including a substantially
* similar Disclaimer requirement for further binary redistribution.
*
* NO WARRANTY
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF NONINFRINGEMENT, MERCHANTIBILITY
* AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
* THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR 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 DAMAGES.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "opt_vm.h"
#include "opt_ddb.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/lock.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/mutex.h>
#if MAXMEMDOM > 1
#include <sys/proc.h>
#endif
#include <sys/queue.h>
#include <sys/rwlock.h>
#include <sys/sbuf.h>
#include <sys/sysctl.h>
#include <sys/tree.h>
#include <sys/vmmeter.h>
#include <sys/seq.h>
#include <ddb/ddb.h>
#include <vm/vm.h>
#include <vm/vm_param.h>
#include <vm/vm_kern.h>
#include <vm/vm_object.h>
#include <vm/vm_page.h>
#include <vm/vm_phys.h>
#include <vm/vm_domain.h>
static __inline int
vm_domain_rr_selectdomain(void)
{
#if MAXMEMDOM > 1
struct thread *td;
td = curthread;
td->td_dom_rr_idx++;
td->td_dom_rr_idx %= vm_ndomains;
return (td->td_dom_rr_idx);
#else
return (0);
#endif
}
/*
* This implements a very simple set of VM domain memory allocation
* policies and iterators.
*/
/*
* A VM domain policy represents a desired VM domain policy.
* Iterators implement searching through VM domains in a specific
* order.
*/
/*
* When setting a policy, the caller must establish their own
* exclusive write protection for the contents of the domain
* policy.
*/
int
vm_domain_policy_init(struct vm_domain_policy *vp)
{
bzero(vp, sizeof(*vp));
vp->p.policy = VM_POLICY_NONE;
vp->p.domain = -1;
return (0);
}
int
vm_domain_policy_set(struct vm_domain_policy *vp,
vm_domain_policy_type_t vt, int domain)
{
seq_write_begin(&vp->seq);
vp->p.policy = vt;
vp->p.domain = domain;
seq_write_end(&vp->seq);
return (0);
}
/*
* Take a local copy of a policy.
*
* The destination policy isn't write-barriered; this is used
* for doing local copies into something that isn't shared.
*/
void
vm_domain_policy_localcopy(struct vm_domain_policy *dst,
const struct vm_domain_policy *src)
{
seq_t seq;
for (;;) {
seq = seq_read(&src->seq);
*dst = *src;
if (seq_consistent(&src->seq, seq))
return;
cpu_spinwait();
}
}
/*
* Take a write-barrier copy of a policy.
*
* The destination policy is write -barriered; this is used
* for doing copies into policies that may be read by other
* threads.
*/
void
vm_domain_policy_copy(struct vm_domain_policy *dst,
const struct vm_domain_policy *src)
{
seq_t seq;
struct vm_domain_policy d;
for (;;) {
seq = seq_read(&src->seq);
d = *src;
if (seq_consistent(&src->seq, seq)) {
seq_write_begin(&dst->seq);
dst->p.domain = d.p.domain;
dst->p.policy = d.p.policy;
seq_write_end(&dst->seq);
return;
}
cpu_spinwait();
}
}
int
vm_domain_policy_validate(const struct vm_domain_policy *vp)
{
switch (vp->p.policy) {
case VM_POLICY_NONE:
case VM_POLICY_ROUND_ROBIN:
case VM_POLICY_FIRST_TOUCH:
case VM_POLICY_FIRST_TOUCH_ROUND_ROBIN:
if (vp->p.domain == -1)
return (0);
return (-1);
case VM_POLICY_FIXED_DOMAIN:
case VM_POLICY_FIXED_DOMAIN_ROUND_ROBIN:
if (vp->p.domain >= 0 && vp->p.domain < vm_ndomains)
return (0);
return (-1);
default:
return (-1);
}
return (-1);
}
int
vm_domain_policy_cleanup(struct vm_domain_policy *vp)
{
/* For now, empty */
return (0);
}
int
vm_domain_iterator_init(struct vm_domain_iterator *vi)
{
/* Nothing to do for now */
return (0);
}
/*
* Manually setup an iterator with the given details.
*/
int
vm_domain_iterator_set(struct vm_domain_iterator *vi,
vm_domain_policy_type_t vt, int domain)
{
switch (vt) {
case VM_POLICY_FIXED_DOMAIN:
vi->policy = VM_POLICY_FIXED_DOMAIN;
vi->domain = domain;
vi->n = 1;
break;
case VM_POLICY_FIXED_DOMAIN_ROUND_ROBIN:
vi->policy = VM_POLICY_FIXED_DOMAIN_ROUND_ROBIN;
vi->domain = domain;
vi->n = vm_ndomains;
break;
case VM_POLICY_FIRST_TOUCH:
vi->policy = VM_POLICY_FIRST_TOUCH;
vi->domain = PCPU_GET(domain);
vi->n = 1;
break;
case VM_POLICY_FIRST_TOUCH_ROUND_ROBIN:
vi->policy = VM_POLICY_FIRST_TOUCH_ROUND_ROBIN;
vi->domain = PCPU_GET(domain);
vi->n = vm_ndomains;
break;
case VM_POLICY_ROUND_ROBIN:
default:
vi->policy = VM_POLICY_ROUND_ROBIN;
vi->domain = -1;
vi->n = vm_ndomains;
break;
}
return (0);
}
/*
* Setup an iterator based on the given policy.
*/
static inline void
_vm_domain_iterator_set_policy(struct vm_domain_iterator *vi,
const struct vm_domain_policy *vt)
{
/*
* Initialise the iterator.
*
* For first-touch, the initial domain is set
* via the current thread CPU domain.
*
* For fixed-domain, it's assumed that the
* caller has initialised the specific domain
* it is after.
*/
switch (vt->p.policy) {
case VM_POLICY_FIXED_DOMAIN:
vi->policy = vt->p.policy;
vi->domain = vt->p.domain;
vi->n = 1;
break;
case VM_POLICY_FIXED_DOMAIN_ROUND_ROBIN:
vi->policy = vt->p.policy;
vi->domain = vt->p.domain;
vi->n = vm_ndomains;
break;
case VM_POLICY_FIRST_TOUCH:
vi->policy = vt->p.policy;
vi->domain = PCPU_GET(domain);
vi->n = 1;
break;
case VM_POLICY_FIRST_TOUCH_ROUND_ROBIN:
vi->policy = vt->p.policy;
vi->domain = PCPU_GET(domain);
vi->n = vm_ndomains;
break;
case VM_POLICY_ROUND_ROBIN:
default:
/*
* Default to round-robin policy.
*/
vi->policy = VM_POLICY_ROUND_ROBIN;
vi->domain = -1;
vi->n = vm_ndomains;
break;
}
}
void
vm_domain_iterator_set_policy(struct vm_domain_iterator *vi,
const struct vm_domain_policy *vt)
{
seq_t seq;
struct vm_domain_policy vt_lcl;
for (;;) {
seq = seq_read(&vt->seq);
vt_lcl = *vt;
if (seq_consistent(&vt->seq, seq)) {
_vm_domain_iterator_set_policy(vi, &vt_lcl);
return;
}
cpu_spinwait();
}
}
/*
* Return the next VM domain to use.
*
* Returns 0 w/ domain set to the next domain to use, or
* -1 to indicate no more domains are available.
*/
int
vm_domain_iterator_run(struct vm_domain_iterator *vi, int *domain)
{
/* General catch-all */
if (vi->n <= 0)
return (-1);
switch (vi->policy) {
case VM_POLICY_FIXED_DOMAIN:
case VM_POLICY_FIRST_TOUCH:
*domain = vi->domain;
vi->n--;
break;
case VM_POLICY_FIXED_DOMAIN_ROUND_ROBIN:
case VM_POLICY_FIRST_TOUCH_ROUND_ROBIN:
/*
* XXX TODO: skip over the rr'ed domain
* if it equals the one we started with.
*/
if (vi->n == vm_ndomains)
*domain = vi->domain;
else
*domain = vm_domain_rr_selectdomain();
vi->n--;
break;
case VM_POLICY_ROUND_ROBIN:
default:
*domain = vm_domain_rr_selectdomain();
vi->n--;
break;
}
return (0);
}
/*
* Returns 1 if the iteration is done, or 0 if it has not.
* This can only be called after at least one loop through
* the iterator. Ie, it's designed to be used as a tail
* check of a loop, not the head check of a loop.
*/
int
vm_domain_iterator_isdone(struct vm_domain_iterator *vi)
{
return (vi->n <= 0);
}
int
vm_domain_iterator_cleanup(struct vm_domain_iterator *vi)
{
return (0);
}
