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uvm_pdpolicy_clockpro.c
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uvm_pdpolicy_clockpro.c
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/* $NetBSD: uvm_pdpolicy_clockpro.c,v 1.9 2007/08/01 14:49:55 yamt Exp $ */
/*-
* Copyright (c)2005, 2006 YAMAMOTO Takashi,
* 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.
* 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 AND CONTRIBUTORS ``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 OR CONTRIBUTORS 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.
*/
/*
* CLOCK-Pro replacement policy:
* http://www.cs.wm.edu/hpcs/WWW/HTML/publications/abs05-3.html
*
* approximation of the list of non-resident pages using hash:
* http://linux-mm.org/ClockProApproximation
*/
/* #define CLOCKPRO_DEBUG */
#if defined(PDSIM)
#include "pdsim.h"
#else /* defined(PDSIM) */
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: uvm_pdpolicy_clockpro.c,v 1.9 2007/08/01 14:49:55 yamt Exp $");
#include "opt_ddb.h"
#include <sys/param.h>
#include <sys/proc.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/hash.h>
#include <uvm/uvm.h>
#include <uvm/uvm_pdpolicy.h>
#include <uvm/uvm_pdpolicy_impl.h>
#if ((__STDC_VERSION__ - 0) >= 199901L)
#define DPRINTF(...) /* nothing */
#define WARN(...) printf(__VA_ARGS__)
#else /* ((__STDC_VERSION__ - 0) >= 199901L) */
#define DPRINTF(a...) /* nothing */ /* GCC */
#define WARN(a...) printf(a)
#endif /* ((__STDC_VERSION__ - 0) >= 199901L) */
#define dump(a) /* nothing */
#undef USEONCE2
#define LISTQ
#undef ADAPTIVE
#endif /* defined(PDSIM) */
#if !defined(CLOCKPRO_COLDPCT)
#define CLOCKPRO_COLDPCT 10
#endif /* !defined(CLOCKPRO_COLDPCT) */
#define CLOCKPRO_COLDPCTMAX 90
#if !defined(CLOCKPRO_HASHFACTOR)
#define CLOCKPRO_HASHFACTOR 2
#endif /* !defined(CLOCKPRO_HASHFACTOR) */
#define CLOCKPRO_NEWQMIN ((1024 * 1024) >> PAGE_SHIFT) /* XXX */
int clockpro_hashfactor = CLOCKPRO_HASHFACTOR;
PDPOL_EVCNT_DEFINE(nresrecordobj)
PDPOL_EVCNT_DEFINE(nresrecordanon)
PDPOL_EVCNT_DEFINE(nreslookupobj)
PDPOL_EVCNT_DEFINE(nreslookupanon)
PDPOL_EVCNT_DEFINE(nresfoundobj)
PDPOL_EVCNT_DEFINE(nresfoundanon)
PDPOL_EVCNT_DEFINE(nresanonfree)
PDPOL_EVCNT_DEFINE(nresconflict)
PDPOL_EVCNT_DEFINE(nresoverwritten)
PDPOL_EVCNT_DEFINE(nreshandhot)
PDPOL_EVCNT_DEFINE(hhottakeover)
PDPOL_EVCNT_DEFINE(hhotref)
PDPOL_EVCNT_DEFINE(hhotunref)
PDPOL_EVCNT_DEFINE(hhotcold)
PDPOL_EVCNT_DEFINE(hhotcoldtest)
PDPOL_EVCNT_DEFINE(hcoldtakeover)
PDPOL_EVCNT_DEFINE(hcoldref)
PDPOL_EVCNT_DEFINE(hcoldunref)
PDPOL_EVCNT_DEFINE(hcoldreftest)
PDPOL_EVCNT_DEFINE(hcoldunreftest)
PDPOL_EVCNT_DEFINE(hcoldunreftestspeculative)
PDPOL_EVCNT_DEFINE(hcoldhot)
PDPOL_EVCNT_DEFINE(speculativeenqueue)
PDPOL_EVCNT_DEFINE(speculativehit1)
PDPOL_EVCNT_DEFINE(speculativehit2)
PDPOL_EVCNT_DEFINE(speculativemiss)
#define PQ_REFERENCED PQ_PRIVATE1
#define PQ_HOT PQ_PRIVATE2
#define PQ_TEST PQ_PRIVATE3
#define PQ_INITIALREF PQ_PRIVATE4
#if PQ_PRIVATE6 != PQ_PRIVATE5 * 2 || PQ_PRIVATE7 != PQ_PRIVATE6 * 2
#error PQ_PRIVATE
#endif
#define PQ_QMASK (PQ_PRIVATE5|PQ_PRIVATE6|PQ_PRIVATE7)
#define PQ_QFACTOR PQ_PRIVATE5
#define PQ_SPECULATIVE PQ_PRIVATE8
#define CLOCKPRO_NOQUEUE 0
#define CLOCKPRO_NEWQ 1 /* small queue to clear initial ref. */
#if defined(LISTQ)
#define CLOCKPRO_COLDQ 2
#define CLOCKPRO_HOTQ 3
#else /* defined(LISTQ) */
#define CLOCKPRO_COLDQ (2 + coldqidx) /* XXX */
#define CLOCKPRO_HOTQ (3 - coldqidx) /* XXX */
#endif /* defined(LISTQ) */
#define CLOCKPRO_LISTQ 4
#define CLOCKPRO_NQUEUE 4
static inline void
clockpro_setq(struct vm_page *pg, int qidx)
{
KASSERT(qidx >= CLOCKPRO_NOQUEUE);
KASSERT(qidx <= CLOCKPRO_NQUEUE);
pg->pqflags = (pg->pqflags & ~PQ_QMASK) | (qidx * PQ_QFACTOR);
}
static inline int
clockpro_getq(struct vm_page *pg)
{
int qidx;
qidx = (pg->pqflags & PQ_QMASK) / PQ_QFACTOR;
KASSERT(qidx >= CLOCKPRO_NOQUEUE);
KASSERT(qidx <= CLOCKPRO_NQUEUE);
return qidx;
}
typedef struct {
struct pglist q_q;
int q_len;
} pageq_t;
struct clockpro_state {
int s_npages;
int s_coldtarget;
int s_ncold;
int s_newqlenmax;
pageq_t s_q[CLOCKPRO_NQUEUE];
struct uvm_pctparam s_coldtargetpct;
};
static pageq_t *
clockpro_queue(struct clockpro_state *s, int qidx)
{
KASSERT(CLOCKPRO_NOQUEUE < qidx);
KASSERT(qidx <= CLOCKPRO_NQUEUE);
return &s->s_q[qidx - 1];
}
#if !defined(LISTQ)
static int coldqidx;
static void
clockpro_switchqueue(void)
{
coldqidx = 1 - coldqidx;
}
#endif /* !defined(LISTQ) */
static struct clockpro_state clockpro;
static struct clockpro_scanstate {
int ss_nscanned;
} scanstate;
/* ---------------------------------------- */
static void
pageq_init(pageq_t *q)
{
TAILQ_INIT(&q->q_q);
q->q_len = 0;
}
static int
pageq_len(const pageq_t *q)
{
return q->q_len;
}
static struct vm_page *
pageq_first(const pageq_t *q)
{
return TAILQ_FIRST(&q->q_q);
}
static void
pageq_insert_tail(pageq_t *q, struct vm_page *pg)
{
TAILQ_INSERT_TAIL(&q->q_q, pg, pageq);
q->q_len++;
}
static void
pageq_insert_head(pageq_t *q, struct vm_page *pg)
{
TAILQ_INSERT_HEAD(&q->q_q, pg, pageq);
q->q_len++;
}
static void
pageq_remove(pageq_t *q, struct vm_page *pg)
{
#if 1
KASSERT(clockpro_queue(&clockpro, clockpro_getq(pg)) == q);
#endif
KASSERT(q->q_len > 0);
TAILQ_REMOVE(&q->q_q, pg, pageq);
q->q_len--;
}
static struct vm_page *
pageq_remove_head(pageq_t *q)
{
struct vm_page *pg;
pg = TAILQ_FIRST(&q->q_q);
if (pg == NULL) {
KASSERT(q->q_len == 0);
return NULL;
}
pageq_remove(q, pg);
return pg;
}
/* ---------------------------------------- */
static void
clockpro_insert_tail(struct clockpro_state *s, int qidx, struct vm_page *pg)
{
pageq_t *q = clockpro_queue(s, qidx);
clockpro_setq(pg, qidx);
pageq_insert_tail(q, pg);
}
static void
clockpro_insert_head(struct clockpro_state *s, int qidx, struct vm_page *pg)
{
pageq_t *q = clockpro_queue(s, qidx);
clockpro_setq(pg, qidx);
pageq_insert_head(q, pg);
}
/* ---------------------------------------- */
typedef uint32_t nonres_cookie_t;
#define NONRES_COOKIE_INVAL 0
typedef uintptr_t objid_t;
/*
* XXX maybe these hash functions need reconsideration,
* given that hash distribution is critical here.
*/
static uint32_t
pageidentityhash1(objid_t obj, off_t idx)
{
uint32_t hash = HASH32_BUF_INIT;
#if 1
hash = hash32_buf(&idx, sizeof(idx), hash);
hash = hash32_buf(&obj, sizeof(obj), hash);
#else
hash = hash32_buf(&obj, sizeof(obj), hash);
hash = hash32_buf(&idx, sizeof(idx), hash);
#endif
return hash;
}
static uint32_t
pageidentityhash2(objid_t obj, off_t idx)
{
uint32_t hash = HASH32_BUF_INIT;
hash = hash32_buf(&obj, sizeof(obj), hash);
hash = hash32_buf(&idx, sizeof(idx), hash);
return hash;
}
static nonres_cookie_t
calccookie(objid_t obj, off_t idx)
{
uint32_t hash = pageidentityhash2(obj, idx);
nonres_cookie_t cookie = hash;
if (__predict_false(cookie == NONRES_COOKIE_INVAL)) {
cookie++; /* XXX */
}
return cookie;
}
#define BUCKETSIZE 14
struct bucket {
int cycle;
int cur;
nonres_cookie_t pages[BUCKETSIZE];
};
static int cycle_target;
static int cycle_target_frac;
static struct bucket static_bucket;
static struct bucket *buckets = &static_bucket;
static size_t hashsize = 1;
static int coldadj;
#define COLDTARGET_ADJ(d) coldadj += (d)
#if defined(PDSIM)
static void *
clockpro_hashalloc(int n)
{
size_t allocsz = sizeof(*buckets) * n;
return malloc(allocsz);
}
static void
clockpro_hashfree(void *p, int n)
{
free(p);
}
#else /* defined(PDSIM) */
static void *
clockpro_hashalloc(int n)
{
size_t allocsz = round_page(sizeof(*buckets) * n);
return (void *)uvm_km_alloc(kernel_map, allocsz, 0, UVM_KMF_WIRED);
}
static void
clockpro_hashfree(void *p, int n)
{
size_t allocsz = round_page(sizeof(*buckets) * n);
uvm_km_free(kernel_map, (vaddr_t)p, allocsz, UVM_KMF_WIRED);
}
#endif /* defined(PDSIM) */
static void
clockpro_hashinit(uint64_t n)
{
struct bucket *newbuckets;
struct bucket *oldbuckets;
size_t sz;
size_t oldsz;
int i;
sz = howmany(n, BUCKETSIZE);
sz *= clockpro_hashfactor;
newbuckets = clockpro_hashalloc(sz);
if (newbuckets == NULL) {
panic("%s: allocation failure", __func__);
}
for (i = 0; i < sz; i++) {
struct bucket *b = &newbuckets[i];
int j;
b->cycle = cycle_target;
b->cur = 0;
for (j = 0; j < BUCKETSIZE; j++) {
b->pages[j] = NONRES_COOKIE_INVAL;
}
}
/* XXX lock */
oldbuckets = buckets;
oldsz = hashsize;
buckets = newbuckets;
hashsize = sz;
/* XXX unlock */
if (oldbuckets != &static_bucket) {
clockpro_hashfree(oldbuckets, oldsz);
}
}
static struct bucket *
nonresident_getbucket(objid_t obj, off_t idx)
{
uint32_t hash;
hash = pageidentityhash1(obj, idx);
return &buckets[hash % hashsize];
}
static void
nonresident_rotate(struct bucket *b)
{
while (b->cycle - cycle_target < 0) {
if (b->pages[b->cur] != NONRES_COOKIE_INVAL) {
PDPOL_EVCNT_INCR(nreshandhot);
COLDTARGET_ADJ(-1);
}
b->pages[b->cur] = NONRES_COOKIE_INVAL;
b->cur = (b->cur + 1) % BUCKETSIZE;
b->cycle++;
}
}
static bool
nonresident_lookupremove(objid_t obj, off_t idx)
{
struct bucket *b = nonresident_getbucket(obj, idx);
nonres_cookie_t cookie = calccookie(obj, idx);
int i;
nonresident_rotate(b);
for (i = 0; i < BUCKETSIZE; i++) {
if (b->pages[i] == cookie) {
b->pages[i] = NONRES_COOKIE_INVAL;
return true;
}
}
return false;
}
static objid_t
pageobj(struct vm_page *pg)
{
const void *obj;
/*
* XXX object pointer is often freed and reused for unrelated object.
* for vnodes, it would be better to use something like
* a hash of fsid/fileid/generation.
*/
obj = pg->uobject;
if (obj == NULL) {
obj = pg->uanon;
KASSERT(obj != NULL);
KASSERT(pg->offset == 0);
}
return (objid_t)obj;
}
static off_t
pageidx(struct vm_page *pg)
{
KASSERT((pg->offset & PAGE_MASK) == 0);
return pg->offset >> PAGE_SHIFT;
}
static bool
nonresident_pagelookupremove(struct vm_page *pg)
{
bool found = nonresident_lookupremove(pageobj(pg), pageidx(pg));
if (pg->uobject) {
PDPOL_EVCNT_INCR(nreslookupobj);
} else {
PDPOL_EVCNT_INCR(nreslookupanon);
}
if (found) {
if (pg->uobject) {
PDPOL_EVCNT_INCR(nresfoundobj);
} else {
PDPOL_EVCNT_INCR(nresfoundanon);
}
}
return found;
}
static void
nonresident_pagerecord(struct vm_page *pg)
{
objid_t obj = pageobj(pg);
off_t idx = pageidx(pg);
struct bucket *b = nonresident_getbucket(obj, idx);
nonres_cookie_t cookie = calccookie(obj, idx);
#if defined(DEBUG)
int i;
for (i = 0; i < BUCKETSIZE; i++) {
if (b->pages[i] == cookie) {
PDPOL_EVCNT_INCR(nresconflict);
}
}
#endif /* defined(DEBUG) */
if (pg->uobject) {
PDPOL_EVCNT_INCR(nresrecordobj);
} else {
PDPOL_EVCNT_INCR(nresrecordanon);
}
nonresident_rotate(b);
if (b->pages[b->cur] != NONRES_COOKIE_INVAL) {
PDPOL_EVCNT_INCR(nresoverwritten);
COLDTARGET_ADJ(-1);
}
b->pages[b->cur] = cookie;
b->cur = (b->cur + 1) % BUCKETSIZE;
}
/* ---------------------------------------- */
#if defined(CLOCKPRO_DEBUG)
static void
check_sanity(void)
{
}
#else /* defined(CLOCKPRO_DEBUG) */
#define check_sanity() /* nothing */
#endif /* defined(CLOCKPRO_DEBUG) */
static void
clockpro_reinit(void)
{
clockpro_hashinit(uvmexp.npages);
}
static void
clockpro_init(void)
{
struct clockpro_state *s = &clockpro;
int i;
for (i = 0; i < CLOCKPRO_NQUEUE; i++) {
pageq_init(&s->s_q[i]);
}
s->s_newqlenmax = 1;
s->s_coldtarget = 1;
uvm_pctparam_init(&s->s_coldtargetpct, CLOCKPRO_COLDPCT, NULL);
}
static void
clockpro_tune(void)
{
struct clockpro_state *s = &clockpro;
int coldtarget;
#if defined(ADAPTIVE)
int coldmax = s->s_npages * CLOCKPRO_COLDPCTMAX / 100;
int coldmin = 1;
coldtarget = s->s_coldtarget;
if (coldtarget + coldadj < coldmin) {
coldadj = coldmin - coldtarget;
} else if (coldtarget + coldadj > coldmax) {
coldadj = coldmax - coldtarget;
}
coldtarget += coldadj;
#else /* defined(ADAPTIVE) */
coldtarget = UVM_PCTPARAM_APPLY(&s->s_coldtargetpct, s->s_npages);
if (coldtarget < 1) {
coldtarget = 1;
}
#endif /* defined(ADAPTIVE) */
s->s_coldtarget = coldtarget;
s->s_newqlenmax = coldtarget / 4;
if (s->s_newqlenmax < CLOCKPRO_NEWQMIN) {
s->s_newqlenmax = CLOCKPRO_NEWQMIN;
}
}
static void
clockpro_movereferencebit(struct vm_page *pg)
{
bool referenced;
referenced = pmap_clear_reference(pg);
if (referenced) {
pg->pqflags |= PQ_REFERENCED;
}
}
static void
clockpro_clearreferencebit(struct vm_page *pg)
{
clockpro_movereferencebit(pg);
pg->pqflags &= ~PQ_REFERENCED;
}
static void
clockpro___newqrotate(int len)
{
struct clockpro_state * const s = &clockpro;
pageq_t * const newq = clockpro_queue(s, CLOCKPRO_NEWQ);
struct vm_page *pg;
while (pageq_len(newq) > len) {
pg = pageq_remove_head(newq);
KASSERT(pg != NULL);
KASSERT(clockpro_getq(pg) == CLOCKPRO_NEWQ);
if ((pg->pqflags & PQ_INITIALREF) != 0) {
clockpro_clearreferencebit(pg);
pg->pqflags &= ~PQ_INITIALREF;
}
/* place at the list head */
clockpro_insert_tail(s, CLOCKPRO_COLDQ, pg);
}
}
static void
clockpro_newqrotate(void)
{
struct clockpro_state * const s = &clockpro;
check_sanity();
clockpro___newqrotate(s->s_newqlenmax);
check_sanity();
}
static void
clockpro_newqflush(int n)
{
check_sanity();
clockpro___newqrotate(n);
check_sanity();
}
static void
clockpro_newqflushone(void)
{
struct clockpro_state * const s = &clockpro;
clockpro_newqflush(
MAX(pageq_len(clockpro_queue(s, CLOCKPRO_NEWQ)) - 1, 0));
}
/*
* our "tail" is called "list-head" in the paper.
*/
static void
clockpro___enqueuetail(struct vm_page *pg)
{
struct clockpro_state * const s = &clockpro;
KASSERT(clockpro_getq(pg) == CLOCKPRO_NOQUEUE);
check_sanity();
#if !defined(USEONCE2)
clockpro_insert_tail(s, CLOCKPRO_NEWQ, pg);
clockpro_newqrotate();
#else /* !defined(USEONCE2) */
#if defined(LISTQ)
KASSERT((pg->pqflags & PQ_REFERENCED) == 0);
#endif /* defined(LISTQ) */
clockpro_insert_tail(s, CLOCKPRO_COLDQ, pg);
#endif /* !defined(USEONCE2) */
check_sanity();
}
static void
clockpro_pageenqueue(struct vm_page *pg)
{
struct clockpro_state * const s = &clockpro;
bool hot;
bool speculative = (pg->pqflags & PQ_SPECULATIVE) != 0; /* XXX */
KASSERT((~pg->pqflags & (PQ_INITIALREF|PQ_SPECULATIVE)) != 0);
UVM_LOCK_ASSERT_PAGEQ();
check_sanity();
KASSERT(clockpro_getq(pg) == CLOCKPRO_NOQUEUE);
s->s_npages++;
pg->pqflags &= ~(PQ_HOT|PQ_TEST);
if (speculative) {
hot = false;
PDPOL_EVCNT_INCR(speculativeenqueue);
} else {
hot = nonresident_pagelookupremove(pg);
if (hot) {
COLDTARGET_ADJ(1);
}
}
/*
* consider mmap'ed file:
*
* - read-ahead enqueues a page.
*
* - on the following read-ahead hit, the fault handler activates it.
*
* - finally, the userland code which caused the above fault
* actually accesses the page. it makes its reference bit set.
*
* we want to count the above as a single access, rather than
* three accesses with short reuse distances.
*/
#if defined(USEONCE2)
pg->pqflags &= ~PQ_INITIALREF;
if (hot) {
pg->pqflags |= PQ_TEST;
}
s->s_ncold++;
clockpro_clearreferencebit(pg);
clockpro___enqueuetail(pg);
#else /* defined(USEONCE2) */
if (speculative) {
s->s_ncold++;
} else if (hot) {
pg->pqflags |= PQ_HOT;
} else {
pg->pqflags |= PQ_TEST;
s->s_ncold++;
}
clockpro___enqueuetail(pg);
#endif /* defined(USEONCE2) */
KASSERT(s->s_ncold <= s->s_npages);
}
static pageq_t *
clockpro_pagequeue(struct vm_page *pg)
{
struct clockpro_state * const s = &clockpro;
int qidx;
qidx = clockpro_getq(pg);
KASSERT(qidx != CLOCKPRO_NOQUEUE);
return clockpro_queue(s, qidx);
}
static void
clockpro_pagedequeue(struct vm_page *pg)
{
struct clockpro_state * const s = &clockpro;
pageq_t *q;
KASSERT(s->s_npages > 0);
check_sanity();
q = clockpro_pagequeue(pg);
pageq_remove(q, pg);
check_sanity();
clockpro_setq(pg, CLOCKPRO_NOQUEUE);
if ((pg->pqflags & PQ_HOT) == 0) {
KASSERT(s->s_ncold > 0);
s->s_ncold--;
}
KASSERT(s->s_npages > 0);
s->s_npages--;
check_sanity();
}
static void
clockpro_pagerequeue(struct vm_page *pg)
{
struct clockpro_state * const s = &clockpro;
int qidx;
qidx = clockpro_getq(pg);
KASSERT(qidx == CLOCKPRO_HOTQ || qidx == CLOCKPRO_COLDQ);
pageq_remove(clockpro_queue(s, qidx), pg);
check_sanity();
clockpro_setq(pg, CLOCKPRO_NOQUEUE);
clockpro___enqueuetail(pg);
}
static void
handhot_endtest(struct vm_page *pg)
{
KASSERT((pg->pqflags & PQ_HOT) == 0);
if ((pg->pqflags & PQ_TEST) != 0) {
PDPOL_EVCNT_INCR(hhotcoldtest);
COLDTARGET_ADJ(-1);
pg->pqflags &= ~PQ_TEST;
} else {
PDPOL_EVCNT_INCR(hhotcold);
}
}
static void
handhot_advance(void)
{
struct clockpro_state * const s = &clockpro;
struct vm_page *pg;
pageq_t *hotq;
int hotqlen;
clockpro_tune();
dump("hot called");
if (s->s_ncold >= s->s_coldtarget) {
return;
}
hotq = clockpro_queue(s, CLOCKPRO_HOTQ);
again:
pg = pageq_first(hotq);
if (pg == NULL) {
DPRINTF("%s: HHOT TAKEOVER\n", __func__);
dump("hhottakeover");
PDPOL_EVCNT_INCR(hhottakeover);
#if defined(LISTQ)
while (/* CONSTCOND */ 1) {
pageq_t *coldq = clockpro_queue(s, CLOCKPRO_COLDQ);
pg = pageq_first(coldq);
if (pg == NULL) {
clockpro_newqflushone();
pg = pageq_first(coldq);
if (pg == NULL) {
WARN("hhot: no page?\n");
return;
}
}
KASSERT(clockpro_pagequeue(pg) == coldq);
pageq_remove(coldq, pg);
check_sanity();
if ((pg->pqflags & PQ_HOT) == 0) {
handhot_endtest(pg);
clockpro_insert_tail(s, CLOCKPRO_LISTQ, pg);
} else {
clockpro_insert_head(s, CLOCKPRO_HOTQ, pg);
break;
}
}
#else /* defined(LISTQ) */
clockpro_newqflush(0); /* XXX XXX */
clockpro_switchqueue();
hotq = clockpro_queue(s, CLOCKPRO_HOTQ);
goto again;
#endif /* defined(LISTQ) */
}
KASSERT(clockpro_pagequeue(pg) == hotq);
/*
* terminate test period of nonresident pages by cycling them.
*/
cycle_target_frac += BUCKETSIZE;
hotqlen = pageq_len(hotq);
while (cycle_target_frac >= hotqlen) {
cycle_target++;
cycle_target_frac -= hotqlen;
}
if ((pg->pqflags & PQ_HOT) == 0) {
#if defined(LISTQ)
panic("cold page in hotq: %p", pg);
#else /* defined(LISTQ) */
handhot_endtest(pg);
goto next;
#endif /* defined(LISTQ) */
}
KASSERT((pg->pqflags & PQ_TEST) == 0);
KASSERT((pg->pqflags & PQ_INITIALREF) == 0);
KASSERT((pg->pqflags & PQ_SPECULATIVE) == 0);
/*
* once we met our target,
* stop at a hot page so that no cold pages in test period
* have larger recency than any hot pages.
*/
if (s->s_ncold >= s->s_coldtarget) {
dump("hot done");
return;
}
clockpro_movereferencebit(pg);
if ((pg->pqflags & PQ_REFERENCED) == 0) {
PDPOL_EVCNT_INCR(hhotunref);
uvmexp.pddeact++;
pg->pqflags &= ~PQ_HOT;
clockpro.s_ncold++;
KASSERT(s->s_ncold <= s->s_npages);
} else {
PDPOL_EVCNT_INCR(hhotref);
}
pg->pqflags &= ~PQ_REFERENCED;
#if !defined(LISTQ)
next:
#endif /* !defined(LISTQ) */
clockpro_pagerequeue(pg);
dump("hot");
goto again;
}
static struct vm_page *
handcold_advance(void)
{
struct clockpro_state * const s = &clockpro;
struct vm_page *pg;
for (;;) {
#if defined(LISTQ)
pageq_t *listq = clockpro_queue(s, CLOCKPRO_LISTQ);
#endif /* defined(LISTQ) */
pageq_t *coldq;
clockpro_newqrotate();
handhot_advance();
#if defined(LISTQ)
pg = pageq_first(listq);
if (pg != NULL) {
KASSERT(clockpro_getq(pg) == CLOCKPRO_LISTQ);
KASSERT((pg->pqflags & PQ_TEST) == 0);
KASSERT((pg->pqflags & PQ_HOT) == 0);
KASSERT((pg->pqflags & PQ_INITIALREF) == 0);
pageq_remove(listq, pg);
check_sanity();
clockpro_insert_head(s, CLOCKPRO_COLDQ, pg); /* XXX */
goto gotcold;
}
#endif /* defined(LISTQ) */
check_sanity();
coldq = clockpro_queue(s, CLOCKPRO_COLDQ);
pg = pageq_first(coldq);
if (pg == NULL) {
clockpro_newqflushone();
pg = pageq_first(coldq);
}
if (pg == NULL) {
DPRINTF("%s: HCOLD TAKEOVER\n", __func__);
dump("hcoldtakeover");
PDPOL_EVCNT_INCR(hcoldtakeover);
KASSERT(
pageq_len(clockpro_queue(s, CLOCKPRO_NEWQ)) == 0);
#if defined(LISTQ)
KASSERT(
pageq_len(clockpro_queue(s, CLOCKPRO_HOTQ)) == 0);
#else /* defined(LISTQ) */
clockpro_switchqueue();
coldq = clockpro_queue(s, CLOCKPRO_COLDQ);
pg = pageq_first(coldq);
#endif /* defined(LISTQ) */
}
if (pg == NULL) {
WARN("hcold: no page?\n");
return NULL;
}
KASSERT((pg->pqflags & PQ_INITIALREF) == 0);
if ((pg->pqflags & PQ_HOT) != 0) {
PDPOL_EVCNT_INCR(hcoldhot);
pageq_remove(coldq, pg);
clockpro_insert_tail(s, CLOCKPRO_HOTQ, pg);
check_sanity();
KASSERT((pg->pqflags & PQ_TEST) == 0);
uvmexp.pdscans++;
continue;
}
#if defined(LISTQ)
gotcold:
#endif /* defined(LISTQ) */