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(2/6) Don't release xbusy in vm_page_remove(), defer to vm_page_free_prep().

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This persists busy state across operations like rename and replace.

Reviewed by:    kib, markj
Tested by:      pho
Sponsored by:   Netflix, Intel
Differential Revision:  https://reviews.freebsd.org/D21549
This commit is contained in:
Jeff Roberson 2019-10-15 03:38:02 +00:00
parent 9551397f51
commit 8da1c09853
4 changed files with 15 additions and 12 deletions
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1
sys/vm/device_pager.c
View File

@ -236,6 +236,7 @@ cdev_pager_free_page(vm_object_t object, vm_page_t m)
KASSERT((m->oflags & VPO_UNMANAGED) == 0, ("unmanaged %p", m));
pmap_remove_all(m);
(void)vm_page_remove(m);
vm_page_xunbusy(m);
} else if (object->type == OBJT_DEVICE)
dev_pager_free_page(object, m);
}

5
sys/vm/vm_fault.c
View File

@ -1231,11 +1231,6 @@ readrest:
fs.object, OFF_TO_IDX(
fs.first_object->backing_object_offset));
#endif
/*
* Removing the page from the backing object
* unbusied it.
*/
vm_page_xbusy(fs.m);
fs.first_m = fs.m;
fs.m = NULL;
VM_CNT_INC(v_cow_optim);

11
sys/vm/vm_object.c
View File

@ -1366,7 +1366,6 @@ retry:
VM_OBJECT_WLOCK(new_object);
goto retry;
}
/* Rename released the xbusy lock. */
#if VM_NRESERVLEVEL > 0
/*
@ -1383,8 +1382,8 @@ retry:
*/
vm_reserv_rename(m, new_object, orig_object, offidxstart);
#endif
if (orig_object->type == OBJT_SWAP)
vm_page_xbusy(m);
if (orig_object->type != OBJT_SWAP)
vm_page_xunbusy(m);
}
if (orig_object->type == OBJT_SWAP) {
/*
@ -1538,6 +1537,8 @@ vm_object_collapse_scan(vm_object_t object, int op)
("freeing mapped page %p", p));
if (vm_page_remove(p))
vm_page_free(p);
else
vm_page_xunbusy(p);
continue;
}
@ -1579,6 +1580,8 @@ vm_object_collapse_scan(vm_object_t object, int op)
("freeing mapped page %p", p));
if (vm_page_remove(p))
vm_page_free(p);
else
vm_page_xunbusy(p);
if (pp != NULL)
vm_page_xunbusy(pp);
continue;
@ -1599,7 +1602,6 @@ vm_object_collapse_scan(vm_object_t object, int op)
op);
continue;
}
/* Rename released the xbusy lock. */
/* Use the old pindex to free the right page. */
if (backing_object->type == OBJT_SWAP)
@ -1613,6 +1615,7 @@ vm_object_collapse_scan(vm_object_t object, int op)
vm_reserv_rename(p, object, backing_object,
backing_offset_index);
#endif
vm_page_xunbusy(p);
}
return (true);
}

10
sys/vm/vm_page.c
View File

@ -1227,6 +1227,8 @@ vm_page_putfake(vm_page_t m)
KASSERT((m->oflags & VPO_UNMANAGED) != 0, ("managed %p", m));
KASSERT((m->flags & PG_FICTITIOUS) != 0,
("vm_page_putfake: bad page %p", m));
if (vm_page_xbusied(m))
vm_page_xunbusy(m);
uma_zfree(fakepg_zone, m);
}
@ -1519,8 +1521,7 @@ vm_page_object_remove(vm_page_t m)
VM_OBJECT_ASSERT_WLOCKED(object);
KASSERT((m->ref_count & VPRC_OBJREF) != 0,
("page %p is missing its object ref", m));
if (vm_page_xbusied(m))
vm_page_xunbusy(m);
mrem = vm_radix_remove(&object->rtree, m->pindex);
KASSERT(mrem == m, ("removed page %p, expected page %p", mrem, m));
@ -3590,7 +3591,7 @@ vm_page_free_prep(vm_page_t m)
VM_CNT_INC(v_tfree);
if (vm_page_sbusied(m))
panic("vm_page_free_prep: freeing busy page %p", m);
panic("vm_page_free_prep: freeing shared busy page %p", m);
if (m->object != NULL) {
vm_page_object_remove(m);
@ -3607,6 +3608,9 @@ vm_page_free_prep(vm_page_t m)
m->ref_count -= VPRC_OBJREF;
}
if (vm_page_xbusied(m))
vm_page_xunbusy(m);
/*
* If fictitious remove object association and
* return.