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authorkib <kib@FreeBSD.org>2017-09-16 13:49:26 +0000
committerLuiz Souza <luiz@netgate.com>2018-02-21 15:13:26 -0300
commitf0ea3d38dfcefcb14e12731990303f5a4ebb5fe4 (patch)
treedb2ebca078f0300b7f67011ae32d6943be444632
parent18ada5c5bdd7305e494b2af51ffa6d334ace2451 (diff)
downloadFreeBSD-src-f0ea3d38dfcefcb14e12731990303f5a4ebb5fe4.zip
FreeBSD-src-f0ea3d38dfcefcb14e12731990303f5a4ebb5fe4.tar.gz
MFC r323368:
Add a vm_page_change_lock() helper. (cherry picked from commit e44297aa7c8b20f74352986ad5c27fed648542cc)
Diffstat
-rw-r--r--sys/vm/vm_object.c26
-rw-r--r--sys/vm/vm_page.c60
-rw-r--r--sys/vm/vm_page.h1
3 files changed, 34 insertions, 53 deletions
diff --git a/sys/vm/vm_object.c b/sys/vm/vm_object.c
index a06d043..ccac79a 100644
--- a/sys/vm/vm_object.c
+++ b/sys/vm/vm_object.c
@@ -1898,6 +1898,7 @@ vm_object_page_remove(vm_object_t object, vm_pindex_t start, vm_pindex_t end,
int options)
{
vm_page_t p, next;
+ struct mtx *mtx;
VM_OBJECT_ASSERT_WLOCKED(object);
KASSERT((object->flags & OBJ_UNMANAGED) == 0 ||
@@ -1908,6 +1909,7 @@ vm_object_page_remove(vm_object_t object, vm_pindex_t start, vm_pindex_t end,
vm_object_pip_add(object, 1);
again:
p = vm_page_find_least(object, start);
+ mtx = NULL;
/*
* Here, the variable "p" is either (1) the page with the least pindex
@@ -1924,7 +1926,7 @@ again:
* however, be invalidated if the option OBJPR_CLEANONLY is
* not specified.
*/
- vm_page_lock(p);
+ vm_page_change_lock(p, &mtx);
if (vm_page_xbusied(p)) {
VM_OBJECT_WUNLOCK(object);
vm_page_busy_sleep(p, "vmopax", true);
@@ -1938,7 +1940,7 @@ again:
p->valid = 0;
vm_page_undirty(p);
}
- goto next;
+ continue;
}
if (vm_page_busied(p)) {
VM_OBJECT_WUNLOCK(object);
@@ -1952,14 +1954,14 @@ again:
if ((options & OBJPR_NOTMAPPED) == 0)
pmap_remove_write(p);
if (p->dirty)
- goto next;
+ continue;
}
if ((options & OBJPR_NOTMAPPED) == 0)
pmap_remove_all(p);
vm_page_free(p);
-next:
- vm_page_unlock(p);
}
+ if (mtx != NULL)
+ mtx_unlock(mtx);
vm_object_pip_wakeup(object);
}
@@ -1982,7 +1984,7 @@ next:
void
vm_object_page_noreuse(vm_object_t object, vm_pindex_t start, vm_pindex_t end)
{
- struct mtx *mtx, *new_mtx;
+ struct mtx *mtx;
vm_page_t p, next;
VM_OBJECT_ASSERT_LOCKED(object);
@@ -1999,17 +2001,7 @@ vm_object_page_noreuse(vm_object_t object, vm_pindex_t start, vm_pindex_t end)
mtx = NULL;
for (; p != NULL && (p->pindex < end || end == 0); p = next) {
next = TAILQ_NEXT(p, listq);
-
- /*
- * Avoid releasing and reacquiring the same page lock.
- */
- new_mtx = vm_page_lockptr(p);
- if (mtx != new_mtx) {
- if (mtx != NULL)
- mtx_unlock(mtx);
- mtx = new_mtx;
- mtx_lock(mtx);
- }
+ vm_page_change_lock(p, &mtx);
vm_page_deactivate_noreuse(p);
}
if (mtx != NULL)
diff --git a/sys/vm/vm_page.c b/sys/vm/vm_page.c
index d8a9c21..3a5e84b 100644
--- a/sys/vm/vm_page.c
+++ b/sys/vm/vm_page.c
@@ -905,6 +905,23 @@ vm_page_flash(vm_page_t m)
}
/*
+ * Avoid releasing and reacquiring the same page lock.
+ */
+void
+vm_page_change_lock(vm_page_t m, struct mtx **mtx)
+{
+ struct mtx *mtx1;
+
+ mtx1 = vm_page_lockptr(m);
+ if (*mtx == mtx1)
+ return;
+ if (*mtx != NULL)
+ mtx_unlock(*mtx);
+ *mtx = mtx1;
+ mtx_lock(mtx1);
+}
+
+/*
* Keep page from being freed by the page daemon
* much of the same effect as wiring, except much lower
* overhead and should be used only for *very* temporary
@@ -937,20 +954,11 @@ vm_page_unhold(vm_page_t mem)
void
vm_page_unhold_pages(vm_page_t *ma, int count)
{
- struct mtx *mtx, *new_mtx;
+ struct mtx *mtx;
mtx = NULL;
for (; count != 0; count--) {
- /*
- * Avoid releasing and reacquiring the same page lock.
- */
- new_mtx = vm_page_lockptr(*ma);
- if (mtx != new_mtx) {
- if (mtx != NULL)
- mtx_unlock(mtx);
- mtx = new_mtx;
- mtx_lock(mtx);
- }
+ vm_page_change_lock(*ma, &mtx);
vm_page_unhold(*ma);
ma++;
}
@@ -1989,7 +1997,7 @@ vm_page_t
vm_page_scan_contig(u_long npages, vm_page_t m_start, vm_page_t m_end,
u_long alignment, vm_paddr_t boundary, int options)
{
- struct mtx *m_mtx, *new_mtx;
+ struct mtx *m_mtx;
vm_object_t object;
vm_paddr_t pa;
vm_page_t m, m_run;
@@ -2032,16 +2040,7 @@ vm_page_scan_contig(u_long npages, vm_page_t m_start, vm_page_t m_end,
} else
KASSERT(m_run != NULL, ("m_run == NULL"));
- /*
- * Avoid releasing and reacquiring the same page lock.
- */
- new_mtx = vm_page_lockptr(m);
- if (m_mtx != new_mtx) {
- if (m_mtx != NULL)
- mtx_unlock(m_mtx);
- m_mtx = new_mtx;
- mtx_lock(m_mtx);
- }
+ vm_page_change_lock(m, &m_mtx);
m_inc = 1;
retry:
if (m->wire_count != 0 || m->hold_count != 0)
@@ -2191,7 +2190,7 @@ static int
vm_page_reclaim_run(int req_class, u_long npages, vm_page_t m_run,
vm_paddr_t high)
{
- struct mtx *m_mtx, *new_mtx;
+ struct mtx *m_mtx;
struct spglist free;
vm_object_t object;
vm_paddr_t pa;
@@ -2212,13 +2211,7 @@ vm_page_reclaim_run(int req_class, u_long npages, vm_page_t m_run,
/*
* Avoid releasing and reacquiring the same page lock.
*/
- new_mtx = vm_page_lockptr(m);
- if (m_mtx != new_mtx) {
- if (m_mtx != NULL)
- mtx_unlock(m_mtx);
- m_mtx = new_mtx;
- mtx_lock(m_mtx);
- }
+ vm_page_change_lock(m, &m_mtx);
retry:
if (m->wire_count != 0 || m->hold_count != 0)
error = EBUSY;
@@ -2331,12 +2324,7 @@ retry:
* The new page must be deactivated
* before the object is unlocked.
*/
- new_mtx = vm_page_lockptr(m_new);
- if (m_mtx != new_mtx) {
- mtx_unlock(m_mtx);
- m_mtx = new_mtx;
- mtx_lock(m_mtx);
- }
+ vm_page_change_lock(m_new, &m_mtx);
vm_page_deactivate(m_new);
} else {
m->flags &= ~PG_ZERO;
diff --git a/sys/vm/vm_page.h b/sys/vm/vm_page.h
index 1ee8dde..00d04c2 100644
--- a/sys/vm/vm_page.h
+++ b/sys/vm/vm_page.h
@@ -448,6 +448,7 @@ vm_page_t vm_page_alloc_contig(vm_object_t object, vm_pindex_t pindex, int req,
u_long npages, vm_paddr_t low, vm_paddr_t high, u_long alignment,
vm_paddr_t boundary, vm_memattr_t memattr);
vm_page_t vm_page_alloc_freelist(int, int);
+void vm_page_change_lock(vm_page_t m, struct mtx **mtx);
vm_page_t vm_page_grab (vm_object_t, vm_pindex_t, int);
int vm_page_try_to_free (vm_page_t);
void vm_page_deactivate (vm_page_t);
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