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Code Issues Releases Activity

Rewrite get_pv_entry() to match expectations of the rest of the

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kernel.  Rather than just kick off the page daemon, we actively retire
more mappings.  The inner loop now looks a lot like the inner loop of
pmap_remove_all.

Also, get_pv_entry can't return NULL now, so remove panic if it did.

Reviewed by:	alc@
This commit is contained in:
Warner Losh 2009-02-12 01:14:49 +00:00
parent 6bf6f10d24
commit f3e39d2a7b
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=188507
1 changed files with 78 additions and 11 deletions
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89
sys/mips/mips/pmap.c
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@ -168,7 +168,7 @@ struct fpage fpages_shared[FPAGES_SHARED];
struct sysmaps sysmaps_pcpu[MAXCPU];
static PMAP_INLINE void free_pv_entry(pv_entry_t pv);
static pv_entry_t get_pv_entry(void);
static pv_entry_t get_pv_entry(pmap_t locked_pmap);
static __inline void pmap_changebit(vm_page_t m, int bit, boolean_t setem);
static int pmap_remove_pte(struct pmap *pmap, pt_entry_t *ptq, vm_offset_t va);
@ -1304,16 +1304,85 @@ free_pv_entry(pv_entry_t pv)
* because of the possibility of allocations at interrupt time.
*/
static pv_entry_t
get_pv_entry(void)
get_pv_entry(pmap_t locked_pmap)
{
static const struct timeval printinterval = { 60, 0 };
static struct timeval lastprint;
struct vpgqueues *vpq;
pt_entry_t *pte, oldpte;
pmap_t pmap;
pv_entry_t allocated_pv, next_pv, pv;
vm_offset_t va;
vm_page_t m;
pv_entry_count++;
if ((pv_entry_count > pv_entry_high_water) &&
(pmap_pagedaemon_waken == 0)) {
pmap_pagedaemon_waken = 1;
wakeup(&vm_pages_needed);
PMAP_LOCK_ASSERT(locked_pmap, MA_OWNED);
mtx_assert(&vm_page_queue_mtx, MA_OWNED);
allocated_pv = uma_zalloc(pvzone, M_NOWAIT);
if (allocated_pv != NULL) {
pv_entry_count++;
if (pv_entry_count > pv_entry_high_water)
pagedaemon_wakeup();
else
return (allocated_pv);
}
return uma_zalloc(pvzone, M_NOWAIT);
/*
* Reclaim pv entries: At first, destroy mappings to inactive
* pages. After that, if a pv entry is still needed, destroy
* mappings to active pages.
*/
if (ratecheck(&lastprint, &printinterval))
printf("Approaching the limit on PV entries, "
"increase the vm.pmap.shpgperproc tunable.\n");
vpq = &vm_page_queues[PQ_INACTIVE];
retry:
TAILQ_FOREACH(m, &vpq->pl, pageq) {
if (m->hold_count || m->busy)
continue;
TAILQ_FOREACH_SAFE(pv, &m->md.pv_list, pv_list, next_pv) {
va = pv->pv_va;
pmap = pv->pv_pmap;
/* Avoid deadlock and lock recursion. */
if (pmap > locked_pmap)
PMAP_LOCK(pmap);
else if (pmap != locked_pmap && !PMAP_TRYLOCK(pmap))
continue;
pmap->pm_stats.resident_count--;
pte = pmap_pte(pmap, va);
KASSERT(pte != NULL, ("pte"));
oldpte = loadandclear((u_int *)pte);
if (is_kernel_pmap(pmap))
*pte = PTE_G;
KASSERT((oldpte & PTE_W) == 0,
("wired pte for unwired page"));
if (m->md.pv_flags & PV_TABLE_REF)
vm_page_flag_set(m, PG_REFERENCED);
if (oldpte & PTE_M)
vm_page_dirty(m);
pmap_invalidate_page(pmap, va);
TAILQ_REMOVE(&pmap->pm_pvlist, pv, pv_plist);
m->md.pv_list_count--;
TAILQ_REMOVE(&m->md.pv_list, pv, pv_list);
if (TAILQ_EMPTY(&m->md.pv_list)) {
vm_page_flag_clear(m, PG_WRITEABLE);
m->md.pv_flags &= ~(PV_TABLE_REF | PV_TABLE_MOD);
}
pmap_unuse_pt(pmap, va, pv->pv_ptem);
if (pmap != locked_pmap)
PMAP_UNLOCK(pmap);
if (allocated_pv == NULL)
allocated_pv = pv;
else
free_pv_entry(pv);
}
}
if (allocated_pv == NULL) {
if (vpq == &vm_page_queues[PQ_INACTIVE]) {
vpq = &vm_page_queues[PQ_ACTIVE];
goto retry;
}
panic("get_pv_entry: increase the vm.pmap.shpgperproc tunable");
}
return (allocated_pv);
}
/*
@ -1376,9 +1445,7 @@ pmap_insert_entry(pmap_t pmap, vm_offset_t va, vm_page_t mpte, vm_page_t m,
pv_entry_t pv;
pv = get_pv_entry();
if (pv == NULL)
panic("no pv entries: increase vm.pmap.shpgperproc");
pv = get_pv_entry(pmap);
pv->pv_va = va;
pv->pv_pmap = pmap;
pv->pv_ptem = mpte;