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Instead of a panic()ing in pmap_insert_entry() if get_pv_entry() fails,

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reclaim a pv entry by destroying a mapping to an inactive page.
This commit is contained in:
Alan Cox 2005-11-02 08:23:28 +00:00
parent 639a1e1106
commit 83ed5ec059
1 changed files with 50 additions and 1 deletions
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51
sys/alpha/alpha/pmap.c
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@ -323,6 +323,7 @@ int pmap_pagedaemon_waken;
static PMAP_INLINE void free_pv_entry(pv_entry_t pv);
static pv_entry_t get_pv_entry(void);
static pv_entry_t pv_entry_reclaim(pmap_t locked_pmap);
static void alpha_protection_init(void);
static void pmap_changebit(vm_page_t m, int bit, boolean_t setem);
@ -1321,6 +1322,54 @@ get_pv_entry(void)
return uma_zalloc(pvzone, M_NOWAIT);
}
/*
* Reclaim a pv entry by removing a mapping to an inactive page.
*/
static pv_entry_t
pv_entry_reclaim(pmap_t locked_pmap)
{
pmap_t pmap;
pt_entry_t *pte, tpte;
pv_entry_t pv;
vm_offset_t va;
vm_page_t m;
PMAP_LOCK_ASSERT(locked_pmap, MA_OWNED);
mtx_assert(&vm_page_queue_mtx, MA_OWNED);
TAILQ_FOREACH(m, &vm_page_queues[PQ_INACTIVE].pl, pageq) {
if (m->hold_count || m->busy || (m->flags & PG_BUSY))
continue;
TAILQ_FOREACH(pv, &m->md.pv_list, pv_list) {
va = pv->pv_va;
pmap = pv->pv_pmap;
if (pmap != locked_pmap && !PMAP_TRYLOCK(pmap))
continue;
pmap->pm_stats.resident_count--;
pte = pmap_lev3pte(pmap, va);
tpte = *pte;
*pte = 0;
KASSERT((tpte & PG_W) == 0,
("pv_entry_reclaim: wired pte %#lx", tpte));
if ((tpte & PG_FOR) == 0)
vm_page_flag_set(m, PG_REFERENCED);
if ((tpte & PG_FOW) == 0) {
if (pmap_track_modified(va))
vm_page_dirty(m);
}
pmap_invalidate_page(pmap, va);
TAILQ_REMOVE(&pmap->pm_pvlist, pv, pv_plist);
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_list_count--;
pmap_unuse_pt(pmap, va, pv->pv_ptem);
if (pmap != locked_pmap)
PMAP_UNLOCK(pmap);
return (pv);
}
}
panic("pv_entry_reclaim: increase vm.pmap.shpgperproc");
}
static int
pmap_remove_entry(pmap_t pmap, vm_page_t m, vm_offset_t va)
@ -1368,7 +1417,7 @@ pmap_insert_entry(pmap_t pmap, vm_offset_t va, vm_page_t mpte, vm_page_t m)
pv = get_pv_entry();
if (pv == NULL)
panic("no pv entries: increase vm.pmap.shpgperproc");
pv = pv_entry_reclaim(pmap);
pv->pv_va = va;
pv->pv_pmap = pmap;
pv->pv_ptem = mpte;