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Move the fast fault path into the separate function.

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Reviewed by:	alc
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
This commit is contained in:
Konstantin Belousov 2016-11-16 16:34:17 +00:00
parent 7804dd5212
commit 41ddec83c1
1 changed files with 50 additions and 30 deletions
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80
sys/vm/vm_fault.c
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@ -246,6 +246,48 @@ vm_fault_dirty(vm_map_entry_t entry, vm_page_t m, vm_prot_t prot,
vm_pager_page_unswapped(m);
}
static void
vm_fault_fill_hold(vm_page_t *m_hold, vm_page_t m)
{
if (m_hold != NULL) {
*m_hold = m;
vm_page_lock(m);
vm_page_hold(m);
vm_page_unlock(m);
}
}
/*
* Unlocks fs.first_object and fs.map on success.
*/
static int
vm_fault_soft_fast(struct faultstate *fs, vm_offset_t vaddr, vm_prot_t prot,
int fault_type, int fault_flags, boolean_t wired, vm_page_t *m_hold)
{
vm_page_t m;
int rv;
MPASS(fs->vp == NULL);
m = vm_page_lookup(fs->first_object, fs->first_pindex);
/* A busy page can be mapped for read|execute access. */
if (m == NULL || ((prot & VM_PROT_WRITE) != 0 &&
vm_page_busied(m)) || m->valid != VM_PAGE_BITS_ALL)
return (KERN_FAILURE);
rv = pmap_enter(fs->map->pmap, vaddr, m, prot, fault_type |
PMAP_ENTER_NOSLEEP | (wired ? PMAP_ENTER_WIRED : 0), 0);
if (rv != KERN_SUCCESS)
return (rv);
vm_fault_fill_hold(m_hold, m);
vm_fault_dirty(fs->entry, m, prot, fault_type, fault_flags, false);
VM_OBJECT_RUNLOCK(fs->first_object);
if (!wired)
vm_fault_prefault(fs, vaddr, PFBAK, PFFOR);
vm_map_lookup_done(fs->map, fs->entry);
curthread->td_ru.ru_minflt++;
return (KERN_SUCCESS);
}
/*
* vm_fault:
*
@ -294,7 +336,6 @@ vm_fault_hold(vm_map_t map, vm_offset_t vaddr, vm_prot_t fault_type,
struct vnode *vp;
vm_object_t next_object, retry_object;
vm_offset_t e_end, e_start;
vm_page_t m;
vm_pindex_t retry_pindex;
vm_prot_t prot, retry_prot;
int ahead, alloc_req, behind, cluster_offset, error, era, faultcount;
@ -376,36 +417,15 @@ RetryFault:;
(fs.first_object->flags & OBJ_TMPFS_NODE) == 0) ||
(fs.first_object->flags & OBJ_MIGHTBEDIRTY) != 0)) {
VM_OBJECT_RLOCK(fs.first_object);
if ((prot & VM_PROT_WRITE) != 0 &&
(fs.first_object->type == OBJT_VNODE ||
(fs.first_object->flags & OBJ_TMPFS_NODE) != 0) &&
(fs.first_object->flags & OBJ_MIGHTBEDIRTY) == 0)
goto fast_failed;
m = vm_page_lookup(fs.first_object, fs.first_pindex);
/* A busy page can be mapped for read|execute access. */
if (m == NULL || ((prot & VM_PROT_WRITE) != 0 &&
vm_page_busied(m)) || m->valid != VM_PAGE_BITS_ALL)
goto fast_failed;
result = pmap_enter(fs.map->pmap, vaddr, m, prot,
fault_type | PMAP_ENTER_NOSLEEP | (wired ? PMAP_ENTER_WIRED :
0), 0);
if (result != KERN_SUCCESS)
goto fast_failed;
if (m_hold != NULL) {
*m_hold = m;
vm_page_lock(m);
vm_page_hold(m);
vm_page_unlock(m);
if ((prot & VM_PROT_WRITE) == 0 ||
(fs.first_object->type != OBJT_VNODE &&
(fs.first_object->flags & OBJ_TMPFS_NODE) == 0) ||
(fs.first_object->flags & OBJ_MIGHTBEDIRTY) != 0) {
rv = vm_fault_soft_fast(&fs, vaddr, prot, fault_type,
fault_flags, wired, m_hold);
if (rv == KERN_SUCCESS)
return (rv);
}
vm_fault_dirty(fs.entry, m, prot, fault_type, fault_flags,
false);
VM_OBJECT_RUNLOCK(fs.first_object);
if (!wired)
vm_fault_prefault(&fs, vaddr, PFBAK, PFFOR);
vm_map_lookup_done(fs.map, fs.entry);
curthread->td_ru.ru_minflt++;
return (KERN_SUCCESS);
fast_failed:
if (!VM_OBJECT_TRYUPGRADE(fs.first_object)) {
VM_OBJECT_RUNLOCK(fs.first_object);
VM_OBJECT_WLOCK(fs.first_object);