svn commit: r357020 - head/sys/vm
Jeff Roberson
jeff at FreeBSD.org
Thu Jan 23 05:03:35 UTC 2020
Author: jeff
Date: Thu Jan 23 05:03:34 2020
New Revision: 357020
URL: https://svnweb.freebsd.org/changeset/base/357020
Log:
(fault 1/9) Move a handful of stack variables into the faultstate.
This additionally fixes a potential bug/pessimization where we could fail to
reload the original fault_type on restart.
Reviewed by: kib, markj
Differential Revision: https://reviews.freebsd.org/D23301
Modified:
head/sys/vm/vm_fault.c
Modified: head/sys/vm/vm_fault.c
==============================================================================
--- head/sys/vm/vm_fault.c Thu Jan 23 04:56:38 2020 (r357019)
+++ head/sys/vm/vm_fault.c Thu Jan 23 05:03:34 2020 (r357020)
@@ -120,19 +120,35 @@ __FBSDID("$FreeBSD$");
#define VM_FAULT_DONTNEED_MIN 1048576
struct faultstate {
- vm_offset_t vaddr;
- vm_page_t m;
+ /* Fault parameters. */
+ vm_offset_t vaddr;
+ vm_page_t *m_hold;
+ vm_prot_t fault_type;
+ vm_prot_t prot;
+ int fault_flags;
+ boolean_t wired;
+
+ /* Page reference for cow. */
vm_page_t m_cow;
- vm_object_t object;
- vm_pindex_t pindex;
- vm_page_t first_m;
+
+ /* Current object. */
+ vm_object_t object;
+ vm_pindex_t pindex;
+ vm_page_t m;
+
+ /* Top-level map object. */
vm_object_t first_object;
- vm_pindex_t first_pindex;
- vm_map_t map;
- vm_map_entry_t entry;
- int map_generation;
- bool lookup_still_valid;
- struct vnode *vp;
+ vm_pindex_t first_pindex;
+ vm_page_t first_m;
+
+ /* Map state. */
+ vm_map_t map;
+ vm_map_entry_t entry;
+ int map_generation;
+ bool lookup_still_valid;
+
+ /* Vnode if locked. */
+ struct vnode *vp;
};
static void vm_fault_dontneed(const struct faultstate *fs, vm_offset_t vaddr,
@@ -233,21 +249,20 @@ unlock_and_deallocate(struct faultstate *fs)
}
static void
-vm_fault_dirty(vm_map_entry_t entry, vm_page_t m, vm_prot_t prot,
- vm_prot_t fault_type, int fault_flags)
+vm_fault_dirty(struct faultstate *fs, vm_page_t m)
{
bool need_dirty;
- if (((prot & VM_PROT_WRITE) == 0 &&
- (fault_flags & VM_FAULT_DIRTY) == 0) ||
+ if (((fs->prot & VM_PROT_WRITE) == 0 &&
+ (fs->fault_flags & VM_FAULT_DIRTY) == 0) ||
(m->oflags & VPO_UNMANAGED) != 0)
return;
VM_PAGE_OBJECT_BUSY_ASSERT(m);
- need_dirty = ((fault_type & VM_PROT_WRITE) != 0 &&
- (fault_flags & VM_FAULT_WIRE) == 0) ||
- (fault_flags & VM_FAULT_DIRTY) != 0;
+ need_dirty = ((fs->fault_type & VM_PROT_WRITE) != 0 &&
+ (fs->fault_flags & VM_FAULT_WIRE) == 0) ||
+ (fs->fault_flags & VM_FAULT_DIRTY) != 0;
vm_object_set_writeable_dirty(m->object);
@@ -268,7 +283,7 @@ vm_fault_dirty(vm_map_entry_t entry, vm_page_t m, vm_p
* sure the page isn't marked NOSYNC. Applications sharing
* data should use the same flags to avoid ping ponging.
*/
- if ((entry->eflags & MAP_ENTRY_NOSYNC) != 0)
+ if ((fs->entry->eflags & MAP_ENTRY_NOSYNC) != 0)
vm_page_aflag_set(m, PGA_NOSYNC);
else
vm_page_aflag_clear(m, PGA_NOSYNC);
@@ -280,8 +295,7 @@ vm_fault_dirty(vm_map_entry_t entry, vm_page_t m, vm_p
* 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_fault_soft_fast(struct faultstate *fs)
{
vm_page_t m, m_map;
#if (defined(__aarch64__) || defined(__amd64__) || (defined(__arm__) && \
@@ -291,12 +305,14 @@ vm_fault_soft_fast(struct faultstate *fs, vm_offset_t
int flags;
#endif
int psind, rv;
+ vm_offset_t vaddr;
MPASS(fs->vp == NULL);
+ vaddr = fs->vaddr;
vm_object_busy(fs->first_object);
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 &&
+ if (m == NULL || ((fs->prot & VM_PROT_WRITE) != 0 &&
vm_page_busied(m)) || !vm_page_all_valid(m)) {
rv = KERN_FAILURE;
goto out;
@@ -311,10 +327,10 @@ vm_fault_soft_fast(struct faultstate *fs, vm_offset_t
rounddown2(vaddr, pagesizes[m_super->psind]) >= fs->entry->start &&
roundup2(vaddr + 1, pagesizes[m_super->psind]) <= fs->entry->end &&
(vaddr & (pagesizes[m_super->psind] - 1)) == (VM_PAGE_TO_PHYS(m) &
- (pagesizes[m_super->psind] - 1)) && !wired &&
+ (pagesizes[m_super->psind] - 1)) && !fs->wired &&
pmap_ps_enabled(fs->map->pmap)) {
flags = PS_ALL_VALID;
- if ((prot & VM_PROT_WRITE) != 0) {
+ if ((fs->prot & VM_PROT_WRITE) != 0) {
/*
* Create a superpage mapping allowing write access
* only if none of the constituent pages are busy and
@@ -331,22 +347,22 @@ vm_fault_soft_fast(struct faultstate *fs, vm_offset_t
vaddr = rounddown2(vaddr, pagesizes[psind]);
/* Preset the modified bit for dirty superpages. */
if ((flags & PS_ALL_DIRTY) != 0)
- fault_type |= VM_PROT_WRITE;
+ fs->fault_type |= VM_PROT_WRITE;
}
}
#endif
- rv = pmap_enter(fs->map->pmap, vaddr, m_map, prot, fault_type |
- PMAP_ENTER_NOSLEEP | (wired ? PMAP_ENTER_WIRED : 0), psind);
+ rv = pmap_enter(fs->map->pmap, vaddr, m_map, fs->prot, fs->fault_type |
+ PMAP_ENTER_NOSLEEP | (fs->wired ? PMAP_ENTER_WIRED : 0), psind);
if (rv != KERN_SUCCESS)
goto out;
- if (m_hold != NULL) {
- *m_hold = m;
+ if (fs->m_hold != NULL) {
+ (*fs->m_hold) = m;
vm_page_wire(m);
}
- if (psind == 0 && !wired)
+ if (psind == 0 && !fs->wired)
vm_fault_prefault(fs, vaddr, PFBAK, PFFOR, true);
VM_OBJECT_RUNLOCK(fs->first_object);
- vm_fault_dirty(fs->entry, m, prot, fault_type, fault_flags);
+ vm_fault_dirty(fs, m);
vm_map_lookup_done(fs->map, fs->entry);
curthread->td_ru.ru_minflt++;
@@ -402,8 +418,7 @@ vm_fault_populate_cleanup(vm_object_t object, vm_pinde
}
static int
-vm_fault_populate(struct faultstate *fs, vm_prot_t prot, int fault_type,
- int fault_flags, boolean_t wired, vm_page_t *m_hold)
+vm_fault_populate(struct faultstate *fs)
{
vm_offset_t vaddr;
vm_page_t m;
@@ -430,7 +445,7 @@ vm_fault_populate(struct faultstate *fs, vm_prot_t pro
* to the driver.
*/
rv = vm_pager_populate(fs->first_object, fs->first_pindex,
- fault_type, fs->entry->max_protection, &pager_first, &pager_last);
+ fs->fault_type, fs->entry->max_protection, &pager_first, &pager_last);
VM_OBJECT_ASSERT_WLOCKED(fs->first_object);
if (rv == VM_PAGER_BAD) {
@@ -489,7 +504,7 @@ vm_fault_populate(struct faultstate *fs, vm_prot_t pro
psind = m->psind;
if (psind > 0 && ((vaddr & (pagesizes[psind] - 1)) != 0 ||
pidx + OFF_TO_IDX(pagesizes[psind]) - 1 > pager_last ||
- !pmap_ps_enabled(fs->map->pmap) || wired))
+ !pmap_ps_enabled(fs->map->pmap) || fs->wired))
psind = 0;
#else
psind = 0;
@@ -497,18 +512,17 @@ vm_fault_populate(struct faultstate *fs, vm_prot_t pro
npages = atop(pagesizes[psind]);
for (i = 0; i < npages; i++) {
vm_fault_populate_check_page(&m[i]);
- vm_fault_dirty(fs->entry, &m[i], prot, fault_type,
- fault_flags);
+ vm_fault_dirty(fs, &m[i]);
}
VM_OBJECT_WUNLOCK(fs->first_object);
- rv = pmap_enter(fs->map->pmap, vaddr, m, prot, fault_type |
- (wired ? PMAP_ENTER_WIRED : 0), psind);
+ rv = pmap_enter(fs->map->pmap, vaddr, m, fs->prot, fs->fault_type |
+ (fs->wired ? PMAP_ENTER_WIRED : 0), psind);
#if defined(__amd64__)
if (psind > 0 && rv == KERN_FAILURE) {
for (i = 0; i < npages; i++) {
rv = pmap_enter(fs->map->pmap, vaddr + ptoa(i),
- &m[i], prot, fault_type |
- (wired ? PMAP_ENTER_WIRED : 0), 0);
+ &m[i], fs->prot, fs->fault_type |
+ (fs->wired ? PMAP_ENTER_WIRED : 0), 0);
MPASS(rv == KERN_SUCCESS);
}
}
@@ -517,12 +531,12 @@ vm_fault_populate(struct faultstate *fs, vm_prot_t pro
#endif
VM_OBJECT_WLOCK(fs->first_object);
for (i = 0; i < npages; i++) {
- if ((fault_flags & VM_FAULT_WIRE) != 0)
+ if ((fs->fault_flags & VM_FAULT_WIRE) != 0)
vm_page_wire(&m[i]);
else
vm_page_activate(&m[i]);
- if (m_hold != NULL && m[i].pindex == fs->first_pindex) {
- *m_hold = &m[i];
+ if (fs->m_hold != NULL && m[i].pindex == fs->first_pindex) {
+ (*fs->m_hold) = &m[i];
vm_page_wire(&m[i]);
}
vm_page_xunbusy(&m[i]);
@@ -778,11 +792,10 @@ vm_fault(vm_map_t map, vm_offset_t vaddr, vm_prot_t fa
vm_object_t next_object, retry_object;
vm_offset_t e_end, e_start;
vm_pindex_t retry_pindex;
- vm_prot_t prot, retry_prot;
+ vm_prot_t retry_prot;
int ahead, alloc_req, behind, cluster_offset, faultcount;
int nera, oom, result, rv;
u_char behavior;
- boolean_t wired; /* Passed by reference. */
bool dead, hardfault, is_first_object_locked;
VM_CNT_INC(v_vm_faults);
@@ -792,6 +805,8 @@ vm_fault(vm_map_t map, vm_offset_t vaddr, vm_prot_t fa
fs.vp = NULL;
fs.vaddr = vaddr;
+ fs.m_hold = m_hold;
+ fs.fault_flags = fault_flags;
faultcount = 0;
nera = -1;
hardfault = false;
@@ -799,15 +814,16 @@ vm_fault(vm_map_t map, vm_offset_t vaddr, vm_prot_t fa
RetryFault:
oom = 0;
RetryFault_oom:
+ fs.fault_type = fault_type;
/*
* Find the backing store object and offset into it to begin the
* search.
*/
fs.map = map;
- result = vm_map_lookup(&fs.map, vaddr, fault_type |
+ result = vm_map_lookup(&fs.map, fs.vaddr, fs.fault_type |
VM_PROT_FAULT_LOOKUP, &fs.entry, &fs.first_object,
- &fs.first_pindex, &prot, &wired);
+ &fs.first_pindex, &fs.prot, &fs.wired);
if (result != KERN_SUCCESS) {
unlock_vp(&fs);
return (result);
@@ -817,14 +833,14 @@ RetryFault_oom:
if (fs.entry->eflags & MAP_ENTRY_NOFAULT) {
panic("%s: fault on nofault entry, addr: %#lx",
- __func__, (u_long)vaddr);
+ __func__, (u_long)fs.vaddr);
}
if (fs.entry->eflags & MAP_ENTRY_IN_TRANSITION &&
fs.entry->wiring_thread != curthread) {
vm_map_unlock_read(fs.map);
vm_map_lock(fs.map);
- if (vm_map_lookup_entry(fs.map, vaddr, &fs.entry) &&
+ if (vm_map_lookup_entry(fs.map, fs.vaddr, &fs.entry) &&
(fs.entry->eflags & MAP_ENTRY_IN_TRANSITION)) {
unlock_vp(&fs);
fs.entry->eflags |= MAP_ENTRY_NEEDS_WAKEUP;
@@ -836,11 +852,11 @@ RetryFault_oom:
MPASS((fs.entry->eflags & MAP_ENTRY_GUARD) == 0);
- if (wired)
- fault_type = prot | (fault_type & VM_PROT_COPY);
+ if (fs.wired)
+ fs.fault_type = fs.prot | (fs.fault_type & VM_PROT_COPY);
else
- KASSERT((fault_flags & VM_FAULT_WIRE) == 0,
- ("!wired && VM_FAULT_WIRE"));
+ KASSERT((fs.fault_flags & VM_FAULT_WIRE) == 0,
+ ("!fs.wired && VM_FAULT_WIRE"));
/*
* Try to avoid lock contention on the top-level object through
@@ -850,10 +866,9 @@ RetryFault_oom:
* multiple page faults of a similar type to run in parallel.
*/
if (fs.vp == NULL /* avoid locked vnode leak */ &&
- (fault_flags & (VM_FAULT_WIRE | VM_FAULT_DIRTY)) == 0) {
+ (fs.fault_flags & (VM_FAULT_WIRE | VM_FAULT_DIRTY)) == 0) {
VM_OBJECT_RLOCK(fs.first_object);
- rv = vm_fault_soft_fast(&fs, vaddr, prot, fault_type,
- fault_flags, wired, m_hold);
+ rv = vm_fault_soft_fast(&fs);
if (rv == KERN_SUCCESS)
return (rv);
if (!VM_OBJECT_TRYUPGRADE(fs.first_object)) {
@@ -950,8 +965,7 @@ RetryFault_oom:
if (fs.object == fs.first_object &&
(fs.first_object->flags & OBJ_POPULATE) != 0 &&
fs.first_object->shadow_count == 0) {
- rv = vm_fault_populate(&fs, prot, fault_type,
- fault_flags, wired, m_hold);
+ rv = vm_fault_populate(&fs);
switch (rv) {
case KERN_SUCCESS:
case KERN_FAILURE:
@@ -1221,7 +1235,7 @@ next:
/*
* We only really need to copy if we want to write it.
*/
- if ((fault_type & (VM_PROT_COPY | VM_PROT_WRITE)) != 0) {
+ if ((fs.fault_type & (VM_PROT_COPY | VM_PROT_WRITE)) != 0) {
/*
* This allows pages to be virtually copied from a
* backing_object into the first_object, where the
@@ -1287,7 +1301,7 @@ next:
*/
pmap_copy_page(fs.m, fs.first_m);
vm_page_valid(fs.first_m);
- if (wired && (fault_flags &
+ if (fs.wired && (fs.fault_flags &
VM_FAULT_WIRE) == 0) {
vm_page_wire(fs.first_m);
vm_page_unwire(fs.m, PQ_INACTIVE);
@@ -1323,7 +1337,7 @@ next:
VM_CNT_INC(v_cow_faults);
curthread->td_cow++;
} else {
- prot &= ~VM_PROT_WRITE;
+ fs.prot &= ~VM_PROT_WRITE;
}
}
@@ -1338,8 +1352,9 @@ next:
}
fs.lookup_still_valid = true;
if (fs.map->timestamp != fs.map_generation) {
- result = vm_map_lookup_locked(&fs.map, vaddr, fault_type,
- &fs.entry, &retry_object, &retry_pindex, &retry_prot, &wired);
+ result = vm_map_lookup_locked(&fs.map, vaddr, fs.fault_type,
+ &fs.entry, &retry_object, &retry_pindex, &retry_prot,
+ &fs.wired);
/*
* If we don't need the page any longer, put it on the inactive
@@ -1371,15 +1386,15 @@ next:
* write to read permission means that we can't mark the page
* write-enabled after all.
*/
- prot &= retry_prot;
- fault_type &= retry_prot;
- if (prot == 0) {
+ fs.prot &= retry_prot;
+ fs.fault_type &= retry_prot;
+ if (fs.prot == 0) {
fault_deallocate(&fs);
goto RetryFault;
}
/* Reassert because wired may have changed. */
- KASSERT(wired || (fault_flags & VM_FAULT_WIRE) == 0,
+ KASSERT(fs.wired || (fs.fault_flags & VM_FAULT_WIRE) == 0,
("!wired && VM_FAULT_WIRE"));
}
}
@@ -1402,7 +1417,7 @@ next:
KASSERT(vm_page_all_valid(fs.m),
("vm_fault: page %p partially invalid", fs.m));
- vm_fault_dirty(fs.entry, fs.m, prot, fault_type, fault_flags);
+ vm_fault_dirty(&fs, fs.m);
/*
* Put this page into the physical map. We had to do the unlock above
@@ -1410,10 +1425,10 @@ next:
* back on the active queue until later so that the pageout daemon
* won't find it (yet).
*/
- pmap_enter(fs.map->pmap, vaddr, fs.m, prot,
- fault_type | (wired ? PMAP_ENTER_WIRED : 0), 0);
- if (faultcount != 1 && (fault_flags & VM_FAULT_WIRE) == 0 &&
- wired == 0)
+ pmap_enter(fs.map->pmap, vaddr, fs.m, fs.prot,
+ fs.fault_type | (fs.wired ? PMAP_ENTER_WIRED : 0), 0);
+ if (faultcount != 1 && (fs.fault_flags & VM_FAULT_WIRE) == 0 &&
+ fs.wired == 0)
vm_fault_prefault(&fs, vaddr,
faultcount > 0 ? behind : PFBAK,
faultcount > 0 ? ahead : PFFOR, false);
@@ -1422,12 +1437,12 @@ next:
* If the page is not wired down, then put it where the pageout daemon
* can find it.
*/
- if ((fault_flags & VM_FAULT_WIRE) != 0)
+ if ((fs.fault_flags & VM_FAULT_WIRE) != 0)
vm_page_wire(fs.m);
else
vm_page_activate(fs.m);
- if (m_hold != NULL) {
- *m_hold = fs.m;
+ if (fs.m_hold != NULL) {
+ (*fs.m_hold) = fs.m;
vm_page_wire(fs.m);
}
vm_page_xunbusy(fs.m);
@@ -1443,7 +1458,7 @@ next:
#ifdef RACCT
if (racct_enable && fs.object->type == OBJT_VNODE) {
PROC_LOCK(curproc);
- if ((fault_type & (VM_PROT_COPY | VM_PROT_WRITE)) != 0) {
+ if ((fs.fault_type & (VM_PROT_COPY | VM_PROT_WRITE)) != 0) {
racct_add_force(curproc, RACCT_WRITEBPS,
PAGE_SIZE + behind * PAGE_SIZE);
racct_add_force(curproc, RACCT_WRITEIOPS, 1);
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