Author: kib
Date: Thu Oct 20 13:12:19 2016
New Revision: 307672
URL: https://svnweb.freebsd.org/changeset/base/307672
Log:
MFC r307218:
Fix a race in vm_page_busy_sleep(9).
Modified:
stable/10/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_vnops.c
stable/10/sys/dev/drm2/i915/i915_gem.c
stable/10/sys/dev/drm2/ttm/ttm_bo_vm.c
stable/10/sys/kern/vfs_bio.c
stable/10/sys/vm/vm_object.c
stable/10/sys/vm/vm_page.c
stable/10/sys/vm/vm_page.h
Directory Properties:
stable/10/ (props changed)
Modified: stable/10/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_vnops.c
==============================================================================
--- stable/10/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_vnops.c
Thu Oct 20 11:42:29 2016 (r307671)
+++ stable/10/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_vnops.c
Thu Oct 20 13:12:19 2016 (r307672)
@@ -421,7 +421,7 @@ page_busy(vnode_t *vp, int64_t start, in
vm_page_reference(pp);
vm_page_lock(pp);
zfs_vmobject_wunlock(obj);
- vm_page_busy_sleep(pp, "zfsmwb");
+ vm_page_busy_sleep(pp, "zfsmwb", true);
zfs_vmobject_wlock(obj);
continue;
}
@@ -476,7 +476,7 @@ page_hold(vnode_t *vp, int64_t start)
vm_page_reference(pp);
vm_page_lock(pp);
zfs_vmobject_wunlock(obj);
- vm_page_busy_sleep(pp, "zfsmwb");
+ vm_page_busy_sleep(pp, "zfsmwb", true);
zfs_vmobject_wlock(obj);
continue;
}
Modified: stable/10/sys/dev/drm2/i915/i915_gem.c
==============================================================================
--- stable/10/sys/dev/drm2/i915/i915_gem.c Thu Oct 20 11:42:29 2016
(r307671)
+++ stable/10/sys/dev/drm2/i915/i915_gem.c Thu Oct 20 13:12:19 2016
(r307672)
@@ -1976,7 +1976,7 @@ retry:
DRM_UNLOCK(dev);
vm_page_lock(m);
VM_OBJECT_WUNLOCK(vm_obj);
- vm_page_busy_sleep(m, "915pee");
+ vm_page_busy_sleep(m, "915pee", false);
goto retry;
}
goto have_page;
@@ -2037,7 +2037,7 @@ retry:
DRM_UNLOCK(dev);
vm_page_lock(m);
VM_OBJECT_WUNLOCK(vm_obj);
- vm_page_busy_sleep(m, "915pbs");
+ vm_page_busy_sleep(m, "915pbs", false);
goto retry;
}
if (vm_page_insert(m, vm_obj, OFF_TO_IDX(offset))) {
Modified: stable/10/sys/dev/drm2/ttm/ttm_bo_vm.c
==============================================================================
--- stable/10/sys/dev/drm2/ttm/ttm_bo_vm.c Thu Oct 20 11:42:29 2016
(r307671)
+++ stable/10/sys/dev/drm2/ttm/ttm_bo_vm.c Thu Oct 20 13:12:19 2016
(r307672)
@@ -239,7 +239,7 @@ reserve:
if (vm_page_busied(m)) {
vm_page_lock(m);
VM_OBJECT_WUNLOCK(vm_obj);
- vm_page_busy_sleep(m, "ttmpbs");
+ vm_page_busy_sleep(m, "ttmpbs", false);
VM_OBJECT_WLOCK(vm_obj);
ttm_mem_io_unlock(man);
ttm_bo_unreserve(bo);
Modified: stable/10/sys/kern/vfs_bio.c
==============================================================================
--- stable/10/sys/kern/vfs_bio.c Thu Oct 20 11:42:29 2016
(r307671)
+++ stable/10/sys/kern/vfs_bio.c Thu Oct 20 13:12:19 2016
(r307672)
@@ -1724,7 +1724,7 @@ brelse(struct buf *bp)
while (vm_page_xbusied(m)) {
vm_page_lock(m);
VM_OBJECT_WUNLOCK(obj);
- vm_page_busy_sleep(m, "mbncsh");
+ vm_page_busy_sleep(m, "mbncsh", true);
VM_OBJECT_WLOCK(obj);
}
if (pmap_page_wired_mappings(m) == 0)
@@ -4069,7 +4069,7 @@ vfs_drain_busy_pages(struct buf *bp)
while (vm_page_xbusied(m)) {
vm_page_lock(m);
VM_OBJECT_WUNLOCK(bp->b_bufobj->bo_object);
- vm_page_busy_sleep(m, "vbpage");
+ vm_page_busy_sleep(m, "vbpage", true);
VM_OBJECT_WLOCK(bp->b_bufobj->bo_object);
}
}
Modified: stable/10/sys/vm/vm_object.c
==============================================================================
--- stable/10/sys/vm/vm_object.c Thu Oct 20 11:42:29 2016
(r307671)
+++ stable/10/sys/vm/vm_object.c Thu Oct 20 13:12:19 2016
(r307672)
@@ -1182,7 +1182,7 @@ shadowlookup:
if (object != tobject)
VM_OBJECT_WUNLOCK(object);
VM_OBJECT_WUNLOCK(tobject);
- vm_page_busy_sleep(m, "madvpo");
+ vm_page_busy_sleep(m, "madvpo", false);
VM_OBJECT_WLOCK(object);
goto relookup;
}
@@ -1361,7 +1361,7 @@ retry:
VM_OBJECT_WUNLOCK(new_object);
vm_page_lock(m);
VM_OBJECT_WUNLOCK(orig_object);
- vm_page_busy_sleep(m, "spltwt");
+ vm_page_busy_sleep(m, "spltwt", false);
VM_OBJECT_WLOCK(orig_object);
VM_OBJECT_WLOCK(new_object);
goto retry;
@@ -1450,7 +1450,7 @@ vm_object_backing_scan_wait(vm_object_t
if (p == NULL)
VM_WAIT;
else
- vm_page_busy_sleep(p, "vmocol");
+ vm_page_busy_sleep(p, "vmocol", false);
VM_OBJECT_WLOCK(object);
VM_OBJECT_WLOCK(backing_object);
return (TAILQ_FIRST(&backing_object->memq));
@@ -1917,7 +1917,7 @@ again:
vm_page_lock(p);
if (vm_page_xbusied(p)) {
VM_OBJECT_WUNLOCK(object);
- vm_page_busy_sleep(p, "vmopax");
+ vm_page_busy_sleep(p, "vmopax", true);
VM_OBJECT_WLOCK(object);
goto again;
}
@@ -1932,7 +1932,7 @@ again:
}
if (vm_page_busied(p)) {
VM_OBJECT_WUNLOCK(object);
- vm_page_busy_sleep(p, "vmopar");
+ vm_page_busy_sleep(p, "vmopar", false);
VM_OBJECT_WLOCK(object);
goto again;
}
Modified: stable/10/sys/vm/vm_page.c
==============================================================================
--- stable/10/sys/vm/vm_page.c Thu Oct 20 11:42:29 2016 (r307671)
+++ stable/10/sys/vm/vm_page.c Thu Oct 20 13:12:19 2016 (r307672)
@@ -601,21 +601,20 @@ vm_page_sunbusy(vm_page_t m)
* This is used to implement the hard-path of busying mechanism.
*
* The given page must be locked.
+ *
+ * If nonshared is true, sleep only if the page is xbusy.
*/
void
-vm_page_busy_sleep(vm_page_t m, const char *wmesg)
+vm_page_busy_sleep(vm_page_t m, const char *wmesg, bool nonshared)
{
u_int x;
- vm_page_lock_assert(m, MA_OWNED);
+ vm_page_assert_locked(m);
x = m->busy_lock;
- if (x == VPB_UNBUSIED) {
- vm_page_unlock(m);
- return;
- }
- if ((x & VPB_BIT_WAITERS) == 0 &&
- !atomic_cmpset_int(&m->busy_lock, x, x | VPB_BIT_WAITERS)) {
+ if (x == VPB_UNBUSIED || (nonshared && (x & VPB_BIT_SHARED) != 0) ||
+ ((x & VPB_BIT_WAITERS) == 0 &&
+ !atomic_cmpset_int(&m->busy_lock, x, x | VPB_BIT_WAITERS))) {
vm_page_unlock(m);
return;
}
@@ -928,7 +927,7 @@ vm_page_sleep_if_busy(vm_page_t m, const
obj = m->object;
vm_page_lock(m);
VM_OBJECT_WUNLOCK(obj);
- vm_page_busy_sleep(m, msg);
+ vm_page_busy_sleep(m, msg, false);
VM_OBJECT_WLOCK(obj);
return (TRUE);
}
@@ -2717,7 +2716,8 @@ retrylookup:
vm_page_aflag_set(m, PGA_REFERENCED);
vm_page_lock(m);
VM_OBJECT_WUNLOCK(object);
- vm_page_busy_sleep(m, "pgrbwt");
+ vm_page_busy_sleep(m, "pgrbwt", (allocflags &
+ VM_ALLOC_IGN_SBUSY) != 0);
VM_OBJECT_WLOCK(object);
goto retrylookup;
} else {
Modified: stable/10/sys/vm/vm_page.h
==============================================================================
--- stable/10/sys/vm/vm_page.h Thu Oct 20 11:42:29 2016 (r307671)
+++ stable/10/sys/vm/vm_page.h Thu Oct 20 13:12:19 2016 (r307672)
@@ -420,7 +420,7 @@ malloc2vm_flags(int malloc_flags)
#endif
void vm_page_busy_downgrade(vm_page_t m);
-void vm_page_busy_sleep(vm_page_t m, const char *msg);
+void vm_page_busy_sleep(vm_page_t m, const char *msg, bool nonshared);
void vm_page_flash(vm_page_t m);
void vm_page_hold(vm_page_t mem);
void vm_page_unhold(vm_page_t mem);
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