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Add a simple pv_page garbage collector (currently disabled).

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This commit is contained in:
mycroft 1994-09-08 21:03:43 +00:00
parent 410ff804f7
commit a90cca9558
1 changed files with 77 additions and 15 deletions
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92
sys/arch/i386/i386/pmap.c
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@ -36,7 +36,7 @@
* SUCH DAMAGE.
*
* from: @(#)pmap.c 7.7 (Berkeley) 5/12/91
* $Id: pmap.c,v 1.20 1994/09/07 20:48:55 mycroft Exp $
* $Id: pmap.c,v 1.21 1994/09/08 21:03:43 mycroft Exp $
*/
/*
@ -172,10 +172,12 @@ vm_offset_t avail_start; /* PA of first available physical page */
vm_offset_t avail_end; /* PA of last available physical page */
vm_offset_t virtual_avail; /* VA of first avail page (after kernel bss)*/
vm_offset_t virtual_end; /* VA of last avail page (end of kernel AS) */
int npages;
boolean_t pmap_initialized = FALSE; /* Has pmap_init completed? */
char *pmap_attributes; /* reference and modify bits */
TAILQ_HEAD(, pv_page) pv_freelist;
TAILQ_HEAD(pv_page_list, pv_page) pv_page_freelist;
int pv_nfree;
pt_entry_t *pmap_pte __P((pmap_t, vm_offset_t));
@ -313,26 +315,26 @@ void
pmap_init()
{
vm_offset_t addr, addr2;
vm_size_t npg, s;
vm_size_t s;
int rv;
extern int KPTphys;
if (PAGE_SIZE != NBPG)
panic("pmap_init: CLSIZE != 1");
npg = pmap_page_index(avail_end - 1) + 1;
s = (vm_size_t) (sizeof(struct pv_entry) * npg + npg);
npages = pmap_page_index(avail_end - 1) + 1;
s = (vm_size_t) (sizeof(struct pv_entry) * npages + npages);
s = round_page(s);
addr = (vm_offset_t) kmem_alloc(kernel_map, s);
pv_table = (struct pv_entry *) addr;
addr += sizeof(struct pv_entry) * npg;
addr += sizeof(struct pv_entry) * npages;
pmap_attributes = (char *) addr;
TAILQ_INIT(&pv_freelist);
TAILQ_INIT(&pv_page_freelist);
#ifdef DEBUG
if (pmapdebug & PDB_INIT)
printf("pmap_init: %x bytes (%x pgs): tbl %x attr %x\n",
s, npg, pv_table, pmap_attributes);
s, npages, pv_table, pmap_attributes);
#endif
/*
@ -348,21 +350,22 @@ pmap_alloc_pv()
struct pv_entry *pv;
int i;
pvp = pv_freelist.tqh_first;
if (pvp == 0) {
if (pv_nfree == 0) {
MALLOC(pvp, struct pv_page *, NBPG, M_VMPVENT, M_NOWAIT);
if (pvp == 0)
panic("pmap_alloc_pv: kmem_alloc() failed");
pvp->pvp_pgi.pgi_nfree = NPVPPG - 1;
pvp->pvp_pgi.pgi_freelist = pv = &pvp->pvp_pv[1];
for (i = NPVPPG - 2; i; i--, pv++)
pv->pv_next = pv + 1;
pv->pv_next = 0;
TAILQ_INSERT_TAIL(&pv_freelist, pvp, pvp_pgi.pgi_list);
pv_nfree += pvp->pvp_pgi.pgi_nfree = NPVPPG - 1;
TAILQ_INSERT_HEAD(&pv_page_freelist, pvp, pvp_pgi.pgi_list);
pv = &pvp->pvp_pv[0];
} else {
--pv_nfree;
pvp = pv_page_freelist.tqh_first;
if (--pvp->pvp_pgi.pgi_nfree == 0) {
TAILQ_REMOVE(&pv_freelist, pvp, pvp_pgi.pgi_list);
TAILQ_REMOVE(&pv_page_freelist, pvp, pvp_pgi.pgi_list);
}
pv = pvp->pvp_pgi.pgi_freelist;
#ifdef DIAGNOSTIC
@ -384,18 +387,77 @@ pmap_free_pv(pv)
pvp = (struct pv_page *) trunc_page(pv);
switch (++pvp->pvp_pgi.pgi_nfree) {
case 1:
TAILQ_INSERT_TAIL(&pv_freelist, pvp, pvp_pgi.pgi_list);
TAILQ_INSERT_TAIL(&pv_page_freelist, pvp, pvp_pgi.pgi_list);
default:
pv->pv_next = pvp->pvp_pgi.pgi_freelist;
pvp->pvp_pgi.pgi_freelist = pv;
++pv_nfree;
break;
case NPVPPG:
TAILQ_REMOVE(&pv_freelist, pvp, pvp_pgi.pgi_list);
pv_nfree -= NPVPPG - 1;
TAILQ_REMOVE(&pv_page_freelist, pvp, pvp_pgi.pgi_list);
FREE(pvp, M_VMPVENT);
break;
}
}
void
pmap_collect_pv()
{
struct pv_page_list pv_page_collectlist;
struct pv_page *pvp, *npvp;
struct pv_entry *ph, *ppv, *pv, *npv;
int s;
TAILQ_INIT(&pv_page_collectlist);
for (pvp = pv_page_freelist.tqh_first; pvp; pvp = npvp) {
if (pv_nfree < NPVPPG)
break;
npvp = pvp->pvp_pgi.pgi_list.tqe_next;
if (pvp->pvp_pgi.pgi_nfree > NPVPPG / 3) {
TAILQ_REMOVE(&pv_page_freelist, pvp, pvp_pgi.pgi_list);
TAILQ_INSERT_TAIL(&pv_page_collectlist, pvp, pvp_pgi.pgi_list);
pv_nfree -= pvp->pvp_pgi.pgi_nfree;
pvp->pvp_pgi.pgi_nfree = -1;
}
}
if (pv_page_collectlist.tqh_first == 0)
return;
for (ph = &pv_table[npages - 1]; ph >= &pv_table[0]; ph--) {
if (ph->pv_pmap == 0)
continue;
s = splimp();
for (ppv = ph; (pv = ppv->pv_next) != 0; ) {
pvp = (struct pv_page *) trunc_page(pv);
if (pvp->pvp_pgi.pgi_nfree == -1) {
pvp = pv_page_freelist.tqh_first;
if (--pvp->pvp_pgi.pgi_nfree == 0) {
TAILQ_REMOVE(&pv_page_freelist, pvp, pvp_pgi.pgi_list);
}
npv = pvp->pvp_pgi.pgi_freelist;
#ifdef DIAGNOSTIC
if (npv == 0)
panic("pmap_collect_pv: pgi_nfree inconsistent");
#endif
pvp->pvp_pgi.pgi_freelist = npv->pv_next;
*npv = *pv;
ppv->pv_next = npv;
ppv = npv;
} else
ppv = pv;
}
splx(s);
}
for (pvp = pv_page_collectlist.tqh_first; pvp; pvp = npvp) {
npvp = pvp->pvp_pgi.pgi_list.tqe_next;
FREE(pvp, M_VMPVENT);
}
}
__inline void
pmap_enter_pv(pmap, va, pind)
register pmap_t pmap;