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A change to KPI of vm_pager_get_pages() and underlying VOP_GETPAGES().

Browse Source 
o With new KPI consumers can request contiguous ranges of pages, and
  unlike before, all pages will be kept busied on return, like it was
  done before with the 'reqpage' only. Now the reqpage goes away. With
  new interface it is easier to implement code protected from race
  conditions.

  Such arrayed requests for now should be preceeded by a call to
  vm_pager_haspage() to make sure that request is possible. This
  could be improved later, making vm_pager_haspage() obsolete.

  Strenghtening the promises on the business of the array of pages
  allows us to remove such hacks as swp_pager_free_nrpage() and
  vm_pager_free_nonreq().

o New KPI accepts two integer pointers that may optionally point at
  values for read ahead and read behind, that a pager may do, if it
  can. These pages are completely owned by pager, and not controlled
  by the caller.

  This shifts the UFS-specific readahead logic from vm_fault.c, which
  should be file system agnostic, into vnode_pager.c. It also removes
  one VOP_BMAP() request per hard fault.

Discussed with:	kib, alc, jeff, scottl
Sponsored by:	Nginx, Inc.
Sponsored by:	Netflix
This commit is contained in:
Gleb Smirnoff 2015-12-16 21:30:45 +00:00
parent bd6c93e8bd
commit b0cd20172d
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=292373
29 changed files with 509 additions and 809 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

19
share/man/man9/VOP_GETPAGES.9
View File

@ -29,7 +29,7 @@
.\"
.\" $FreeBSD$
.\"
.Dd September 12, 2014
.Dd December 16, 2015
.Dt VOP_GETPAGES 9
.Os
.Sh NAME
@ -41,7 +41,7 @@
.In sys/vnode.h
.In vm/vm.h
.Ft int
.Fn VOP_GETPAGES "struct vnode *vp" "vm_page_t *ma" "int count" "int reqpage"
.Fn VOP_GETPAGES "struct vnode *vp" "vm_page_t *ma" "int count" "int *rbehind" "int *rahead"
.Ft int
.Fn VOP_PUTPAGES "struct vnode *vp" "vm_page_t *ma" "int count" "int sync" "int *rtvals"
.Sh DESCRIPTION
@ -63,7 +63,7 @@ locks are held.
Both methods return in the same state on both success and error returns.
.Pp
The arguments are:
.Bl -tag -width reqpage
.Bl -tag -width rbehind
.It Fa vp
The file to access.
.It Fa ma
@ -78,9 +78,16 @@ if the write should be synchronous.
An array of VM system result codes indicating the status of each
page written by
.Fn VOP_PUTPAGES .
.It Fa reqpage
The index in the page array of the requested page; i.e., the one page which
the implementation of this method must handle.
.It Fa rbehind
Optional pointer to integer specifying number of pages to be read behind, if
possible.
If the filesystem supports that feature, number of actually read pages is
reported back, otherwise zero is returned.
.It Fa rahead
Optional pointer to integer specifying number of pages to be read ahead, if
possible.
If the filesystem supports that feature, number of actually read pages is
reported back, otherwise zero is returned.
.El
.Pp
The status of the

97
sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_vnops.c
View File

@ -5762,12 +5762,13 @@ ioflags(int ioflags)
}
static int
zfs_getpages(struct vnode *vp, vm_page_t *m, int count, int reqpage)
zfs_getpages(struct vnode *vp, vm_page_t *m, int count, int *rbehind,
int *rahead)
{
znode_t *zp = VTOZ(vp);
zfsvfs_t *zfsvfs = zp->z_zfsvfs;
objset_t *os = zp->z_zfsvfs->z_os;
vm_page_t mfirst, mlast, mreq;
vm_page_t mlast;
vm_object_t object;
caddr_t va;
struct sf_buf *sf;
@ -5776,82 +5777,46 @@ zfs_getpages(struct vnode *vp, vm_page_t *m, int count, int reqpage)
vm_pindex_t reqstart, reqend;
int pcount, lsize, reqsize, size;
if (rbehind)
*rbehind = 0;
if (rahead)
*rahead = 0;
ZFS_ENTER(zfsvfs);
ZFS_VERIFY_ZP(zp);
pcount = OFF_TO_IDX(round_page(count));
mreq = m[reqpage];
object = mreq->object;
error = 0;
if (pcount > 1 && zp->z_blksz > PAGESIZE) {
startoff = rounddown(IDX_TO_OFF(mreq->pindex), zp->z_blksz);
reqstart = OFF_TO_IDX(round_page(startoff));
if (reqstart < m[0]->pindex)
reqstart = 0;
else
reqstart = reqstart - m[0]->pindex;
endoff = roundup(IDX_TO_OFF(mreq->pindex) + PAGE_SIZE,
zp->z_blksz);
reqend = OFF_TO_IDX(trunc_page(endoff)) - 1;
if (reqend > m[pcount - 1]->pindex)
reqend = m[pcount - 1]->pindex;
reqsize = reqend - m[reqstart]->pindex + 1;
KASSERT(reqstart <= reqpage && reqpage < reqstart + reqsize,
("reqpage beyond [reqstart, reqstart + reqsize[ bounds"));
} else {
reqstart = reqpage;
reqsize = 1;
}
mfirst = m[reqstart];
mlast = m[reqstart + reqsize - 1];
zfs_vmobject_wlock(object);
for (i = 0; i < reqstart; i++) {
vm_page_lock(m[i]);
vm_page_free(m[i]);
vm_page_unlock(m[i]);
}
for (i = reqstart + reqsize; i < pcount; i++) {
vm_page_lock(m[i]);
vm_page_free(m[i]);
vm_page_unlock(m[i]);
}
if (mreq->valid && reqsize == 1) {
if (mreq->valid != VM_PAGE_BITS_ALL)
vm_page_zero_invalid(mreq, TRUE);
if (m[pcount - 1]->valid != 0 && --pcount == 0) {
zfs_vmobject_wunlock(object);
ZFS_EXIT(zfsvfs);
return (zfs_vm_pagerret_ok);
}
PCPU_INC(cnt.v_vnodein);
PCPU_ADD(cnt.v_vnodepgsin, reqsize);
object = m[0]->object;
mlast = m[pcount - 1];
if (IDX_TO_OFF(mreq->pindex) >= object->un_pager.vnp.vnp_size) {
for (i = reqstart; i < reqstart + reqsize; i++) {
if (i != reqpage) {
vm_page_lock(m[i]);
vm_page_free(m[i]);
vm_page_unlock(m[i]);
}
}
if (IDX_TO_OFF(mlast->pindex) >=
object->un_pager.vnp.vnp_size) {
zfs_vmobject_wunlock(object);
ZFS_EXIT(zfsvfs);
return (zfs_vm_pagerret_bad);
}
PCPU_INC(cnt.v_vnodein);
PCPU_ADD(cnt.v_vnodepgsin, reqsize);
lsize = PAGE_SIZE;
if (IDX_TO_OFF(mlast->pindex) + lsize > object->un_pager.vnp.vnp_size)
lsize = object->un_pager.vnp.vnp_size - IDX_TO_OFF(mlast->pindex);
lsize = object->un_pager.vnp.vnp_size -
IDX_TO_OFF(mlast->pindex);
zfs_vmobject_wunlock(object);
for (i = reqstart; i < reqstart + reqsize; i++) {
error = 0;
for (i = 0; i < pcount; i++) {
size = PAGE_SIZE;
if (i == (reqstart + reqsize - 1))
if (i == pcount - 1)
size = lsize;
va = zfs_map_page(m[i], &sf);
error = dmu_read(os, zp->z_id, IDX_TO_OFF(m[i]->pindex),
@ -5860,21 +5825,15 @@ zfs_getpages(struct vnode *vp, vm_page_t *m, int count, int reqpage)
bzero(va + size, PAGE_SIZE - size);
zfs_unmap_page(sf);
if (error != 0)
break;
goto out;
}
zfs_vmobject_wlock(object);
for (i = reqstart; i < reqstart + reqsize; i++) {
if (!error)
m[i]->valid = VM_PAGE_BITS_ALL;
KASSERT(m[i]->dirty == 0, ("zfs_getpages: page %p is dirty", m[i]));
if (i != reqpage)
vm_page_readahead_finish(m[i]);
}
for (i = 0; i < pcount; i++)
m[i]->valid = VM_PAGE_BITS_ALL;
zfs_vmobject_wunlock(object);
out:
ZFS_ACCESSTIME_STAMP(zfsvfs, zp);
ZFS_EXIT(zfsvfs);
return (error ? zfs_vm_pagerret_error : zfs_vm_pagerret_ok);
@ -5886,11 +5845,13 @@ zfs_freebsd_getpages(ap)
struct vnode *a_vp;
vm_page_t *a_m;
int a_count;
int a_reqpage;
int *a_rbehind;
int *a_rahead;
} */ *ap;
{
return (zfs_getpages(ap->a_vp, ap->a_m, ap->a_count, ap->a_reqpage));
return (zfs_getpages(ap->a_vp, ap->a_m, ap->a_count, ap->a_rbehind,
ap->a_rahead));
}
static int

2
sys/dev/drm2/i915/i915_gem.c
View File

@ -4338,7 +4338,7 @@ i915_gem_wire_page(vm_object_t object, vm_pindex_t pindex, bool *fresh)
page = vm_page_grab(object, pindex, VM_ALLOC_NORMAL);
if (page->valid != VM_PAGE_BITS_ALL) {
if (vm_pager_has_page(object, pindex, NULL, NULL)) {
rv = vm_pager_get_pages(object, &page, 1, 0);
rv = vm_pager_get_pages(object, &page, 1, NULL, NULL);
if (rv != VM_PAGER_OK) {
vm_page_lock(page);
vm_page_free(page);

3
sys/dev/drm2/ttm/ttm_tt.c
View File

@ -291,7 +291,8 @@ int ttm_tt_swapin(struct ttm_tt *ttm)
from_page = vm_page_grab(obj, i, VM_ALLOC_NORMAL);
if (from_page->valid != VM_PAGE_BITS_ALL) {
if (vm_pager_has_page(obj, i, NULL, NULL)) {
rv = vm_pager_get_pages(obj, &from_page, 1, 0);
rv = vm_pager_get_pages(obj, &from_page, 1,
NULL, NULL);
if (rv != VM_PAGER_OK) {
vm_page_lock(from_page);
vm_page_free(from_page);

9
sys/dev/md/md.c
View File

@ -1019,7 +1019,8 @@ mdstart_swap(struct md_s *sc, struct bio *bp)
if (m->valid == VM_PAGE_BITS_ALL)
rv = VM_PAGER_OK;
else
rv = vm_pager_get_pages(sc->object, &m, 1, 0);
rv = vm_pager_get_pages(sc->object, &m, 1,
NULL, NULL);
if (rv == VM_PAGER_ERROR) {
vm_page_xunbusy(m);
break;
@ -1046,7 +1047,8 @@ mdstart_swap(struct md_s *sc, struct bio *bp)
}
} else if (bp->bio_cmd == BIO_WRITE) {
if (len != PAGE_SIZE && m->valid != VM_PAGE_BITS_ALL)
rv = vm_pager_get_pages(sc->object, &m, 1, 0);
rv = vm_pager_get_pages(sc->object, &m, 1,
NULL, NULL);
else
rv = VM_PAGER_OK;
if (rv == VM_PAGER_ERROR) {
@ -1065,7 +1067,8 @@ mdstart_swap(struct md_s *sc, struct bio *bp)
m->valid = VM_PAGE_BITS_ALL;
} else if (bp->bio_cmd == BIO_DELETE) {
if (len != PAGE_SIZE && m->valid != VM_PAGE_BITS_ALL)
rv = vm_pager_get_pages(sc->object, &m, 1, 0);
rv = vm_pager_get_pages(sc->object, &m, 1,
NULL, NULL);
else
rv = VM_PAGER_OK;
if (rv == VM_PAGER_ERROR) {

46
sys/fs/fuse/fuse_vnops.c
View File

@ -1753,6 +1753,10 @@ fuse_vnop_getpages(struct vop_getpages_args *ap)
cred = curthread->td_ucred; /* XXX */
pages = ap->a_m;
count = ap->a_count;
if (ap->a_rbehind)
*ap->a_rbehind = 0;
if (ap->a_rahead)
*ap->a_rahead = 0;
if (!fsess_opt_mmap(vnode_mount(vp))) {
FS_DEBUG("called on non-cacheable vnode??\n");
@ -1761,26 +1765,21 @@ fuse_vnop_getpages(struct vop_getpages_args *ap)
npages = btoc(count);
/*
* If the requested page is partially valid, just return it and
* allow the pager to zero-out the blanks. Partially valid pages
* can only occur at the file EOF.
* If the last page is partially valid, just return it and allow
* the pager to zero-out the blanks. Partially valid pages can
* only occur at the file EOF.
*
* XXXGL: is that true for FUSE, which is a local filesystem,
* but still somewhat disconnected from the kernel?
*/
VM_OBJECT_WLOCK(vp->v_object);
fuse_vm_page_lock_queues();
if (pages[ap->a_reqpage]->valid != 0) {
for (i = 0; i < npages; ++i) {
if (i != ap->a_reqpage) {
fuse_vm_page_lock(pages[i]);
vm_page_free(pages[i]);
fuse_vm_page_unlock(pages[i]);
}
if (pages[npages - 1]->valid != 0) {
if (--npages == 0) {
VM_OBJECT_WUNLOCK(vp->v_object);
return (VM_PAGER_OK);
}
fuse_vm_page_unlock_queues();
VM_OBJECT_WUNLOCK(vp->v_object);
return 0;
}
fuse_vm_page_unlock_queues();
count = npages << PAGE_SHIFT;
}
VM_OBJECT_WUNLOCK(vp->v_object);
/*
@ -1811,17 +1810,6 @@ fuse_vnop_getpages(struct vop_getpages_args *ap)
if (error && (uio.uio_resid == count)) {
FS_DEBUG("error %d\n", error);
VM_OBJECT_WLOCK(vp->v_object);
fuse_vm_page_lock_queues();
for (i = 0; i < npages; ++i) {
if (i != ap->a_reqpage) {
fuse_vm_page_lock(pages[i]);
vm_page_free(pages[i]);
fuse_vm_page_unlock(pages[i]);
}
}
fuse_vm_page_unlock_queues();
VM_OBJECT_WUNLOCK(vp->v_object);
return VM_PAGER_ERROR;
}
/*
@ -1862,8 +1850,6 @@ fuse_vnop_getpages(struct vop_getpages_args *ap)
*/
;
}
if (i != ap->a_reqpage)
vm_page_readahead_finish(m);
}
fuse_vm_page_unlock_queues();
VM_OBJECT_WUNLOCK(vp->v_object);

22
sys/fs/nfsclient/nfs_clbio.c
View File

@ -101,6 +101,10 @@ ncl_getpages(struct vop_getpages_args *ap)
nmp = VFSTONFS(vp->v_mount);
pages = ap->a_m;
count = ap->a_count;
if (ap->a_rbehind)
*ap->a_rbehind = 0;
if (ap->a_rahead)
*ap->a_rahead = 0;
if ((object = vp->v_object) == NULL) {
ncl_printf("nfs_getpages: called with non-merged cache vnode??\n");
@ -132,12 +136,18 @@ ncl_getpages(struct vop_getpages_args *ap)
* If the requested page is partially valid, just return it and
* allow the pager to zero-out the blanks. Partially valid pages
* can only occur at the file EOF.
*
* XXXGL: is that true for NFS, where short read can occur???
*/
if (pages[ap->a_reqpage]->valid != 0) {
vm_pager_free_nonreq(object, pages, ap->a_reqpage, npages,
FALSE);
return (VM_PAGER_OK);
VM_OBJECT_WLOCK(object);
if (pages[npages - 1]->valid != 0) {
if (--npages == 0) {
VM_OBJECT_WUNLOCK(object);
return (VM_PAGER_OK);
}
count = npages << PAGE_SHIFT;
}
VM_OBJECT_WUNLOCK(object);
/*
* We use only the kva address for the buffer, but this is extremely
@ -167,8 +177,6 @@ ncl_getpages(struct vop_getpages_args *ap)
if (error && (uio.uio_resid == count)) {
ncl_printf("nfs_getpages: error %d\n", error);
vm_pager_free_nonreq(object, pages, ap->a_reqpage, npages,
FALSE);
return (VM_PAGER_ERROR);
}
@ -212,8 +220,6 @@ ncl_getpages(struct vop_getpages_args *ap)
*/
;
}
if (i != ap->a_reqpage)
vm_page_readahead_finish(m);
}
VM_OBJECT_WUNLOCK(object);
return (0);

40
sys/fs/smbfs/smbfs_io.c
View File

@ -424,7 +424,7 @@ smbfs_getpages(ap)
#ifdef SMBFS_RWGENERIC
return vop_stdgetpages(ap);
#else
int i, error, nextoff, size, toff, npages, count, reqpage;
int i, error, nextoff, size, toff, npages, count;
struct uio uio;
struct iovec iov;
vm_offset_t kva;
@ -436,7 +436,7 @@ smbfs_getpages(ap)
struct smbnode *np;
struct smb_cred *scred;
vm_object_t object;
vm_page_t *pages, m;
vm_page_t *pages;
vp = ap->a_vp;
if ((object = vp->v_object) == NULL) {
@ -451,26 +451,25 @@ smbfs_getpages(ap)
pages = ap->a_m;
count = ap->a_count;
npages = btoc(count);
reqpage = ap->a_reqpage;
if (ap->a_rbehind)
*ap->a_rbehind = 0;
if (ap->a_rahead)
*ap->a_rahead = 0;
/*
* If the requested page is partially valid, just return it and
* allow the pager to zero-out the blanks. Partially valid pages
* can only occur at the file EOF.
*
* XXXGL: is that true for SMB filesystem?
*/
m = pages[reqpage];
VM_OBJECT_WLOCK(object);
if (m->valid != 0) {
for (i = 0; i < npages; ++i) {
if (i != reqpage) {
vm_page_lock(pages[i]);
vm_page_free(pages[i]);
vm_page_unlock(pages[i]);
}
if (pages[npages - 1]->valid != 0) {
if (--npages == 0) {
VM_OBJECT_WUNLOCK(object);
return (VM_PAGER_OK);
}
VM_OBJECT_WUNLOCK(object);
return 0;
count = npages << PAGE_SHIFT;
}
VM_OBJECT_WUNLOCK(object);
@ -500,22 +499,14 @@ smbfs_getpages(ap)
relpbuf(bp, &smbfs_pbuf_freecnt);
VM_OBJECT_WLOCK(object);
if (error && (uio.uio_resid == count)) {
printf("smbfs_getpages: error %d\n",error);
for (i = 0; i < npages; i++) {
if (reqpage != i) {
vm_page_lock(pages[i]);
vm_page_free(pages[i]);
vm_page_unlock(pages[i]);
}
}
VM_OBJECT_WUNLOCK(object);
return VM_PAGER_ERROR;
}
size = count - uio.uio_resid;
VM_OBJECT_WLOCK(object);
for (i = 0, toff = 0; i < npages; i++, toff = nextoff) {
vm_page_t m;
nextoff = toff + PAGE_SIZE;
@ -544,9 +535,6 @@ smbfs_getpages(ap)
*/
;
}
if (i != reqpage)
vm_page_readahead_finish(m);
}
VM_OBJECT_WUNLOCK(object);
return 0;

3
sys/fs/tmpfs/tmpfs_subr.c
View File

@ -1370,7 +1370,8 @@ tmpfs_reg_resize(struct vnode *vp, off_t newsize, boolean_t ignerr)
VM_OBJECT_WLOCK(uobj);
goto retry;
} else if (m->valid != VM_PAGE_BITS_ALL)
rv = vm_pager_get_pages(uobj, &m, 1, 0);
rv = vm_pager_get_pages(uobj, &m, 1,
NULL, NULL);
else
/* A cached page was reactivated. */
rv = VM_PAGER_OK;

31
sys/kern/kern_exec.c
View File

@ -950,8 +950,7 @@ int
exec_map_first_page(imgp)
struct image_params *imgp;
{
int rv, i;
int initial_pagein;
int rv, i, after, initial_pagein;
vm_page_t ma[VM_INITIAL_PAGEIN];
vm_object_t object;
@ -967,9 +966,18 @@ exec_map_first_page(imgp)
#endif
ma[0] = vm_page_grab(object, 0, VM_ALLOC_NORMAL);
if (ma[0]->valid != VM_PAGE_BITS_ALL) {
initial_pagein = VM_INITIAL_PAGEIN;
if (initial_pagein > object->size)
initial_pagein = object->size;
if (!vm_pager_has_page(object, 0, NULL, &after)) {
vm_page_lock(ma[0]);
vm_page_free(ma[0]);
vm_page_unlock(ma[0]);
vm_page_xunbusy(ma[0]);
VM_OBJECT_WUNLOCK(object);
return (EIO);
}
initial_pagein = min(after, VM_INITIAL_PAGEIN);
KASSERT(initial_pagein <= object->size,
("%s: initial_pagein %d object->size %ju",
__func__, initial_pagein, (uintmax_t )object->size));
for (i = 1; i < initial_pagein; i++) {
if ((ma[i] = vm_page_next(ma[i - 1])) != NULL) {
if (ma[i]->valid)
@ -984,14 +992,19 @@ exec_map_first_page(imgp)
}
}
initial_pagein = i;
rv = vm_pager_get_pages(object, ma, initial_pagein, 0);
rv = vm_pager_get_pages(object, ma, initial_pagein, NULL, NULL);
if (rv != VM_PAGER_OK) {
vm_page_lock(ma[0]);
vm_page_free(ma[0]);
vm_page_unlock(ma[0]);
for (i = 0; i < initial_pagein; i++) {
vm_page_lock(ma[i]);
vm_page_free(ma[i]);
vm_page_unlock(ma[i]);
vm_page_xunbusy(ma[i]);
}
VM_OBJECT_WUNLOCK(object);
return (EIO);
}
for (i = 1; i < initial_pagein; i++)
vm_page_readahead_finish(ma[i]);
}
vm_page_xunbusy(ma[0]);
vm_page_lock(ma[0]);

4
sys/kern/uipc_shm.c
View File

@ -189,7 +189,7 @@ uiomove_object_page(vm_object_t obj, size_t len, struct uio *uio)
m = vm_page_grab(obj, idx, VM_ALLOC_NORMAL);
if (m->valid != VM_PAGE_BITS_ALL) {
if (vm_pager_has_page(obj, idx, NULL, NULL)) {
rv = vm_pager_get_pages(obj, &m, 1, 0);
rv = vm_pager_get_pages(obj, &m, 1, NULL, NULL);
if (rv != VM_PAGER_OK) {
printf(
"uiomove_object: vm_obj %p idx %jd valid %x pager error %d\n",
@ -460,7 +460,7 @@ shm_dotruncate(struct shmfd *shmfd, off_t length)
goto retry;
} else if (m->valid != VM_PAGE_BITS_ALL)
rv = vm_pager_get_pages(object, &m, 1,
0);
NULL, NULL);
else
/* A cached page was reactivated. */
rv = VM_PAGER_OK;

2
sys/kern/uipc_syscalls.c
View File

@ -2033,7 +2033,7 @@ sendfile_readpage(vm_object_t obj, struct vnode *vp, int nd,
VM_OBJECT_WLOCK(obj);
} else {
if (vm_pager_has_page(obj, pindex, NULL, NULL)) {
rv = vm_pager_get_pages(obj, &m, 1, 0);
rv = vm_pager_get_pages(obj, &m, 1, NULL, NULL);
SFSTAT_INC(sf_iocnt);
if (rv != VM_PAGER_OK) {
vm_page_lock(m);

10
sys/kern/vfs_default.c
View File

@ -731,12 +731,13 @@ vop_stdgetpages(ap)
struct vnode *a_vp;
vm_page_t *a_m;
int a_count;
int a_reqpage;
int *a_rbehind;
int *a_rahead;
} */ *ap;
{
return vnode_pager_generic_getpages(ap->a_vp, ap->a_m,
ap->a_count, ap->a_reqpage, NULL, NULL);
ap->a_count, ap->a_rbehind, ap->a_rahead, NULL, NULL);
}
static int
@ -744,8 +745,9 @@ vop_stdgetpages_async(struct vop_getpages_async_args *ap)
{
int error;
error = VOP_GETPAGES(ap->a_vp, ap->a_m, ap->a_count, ap->a_reqpage);
ap->a_iodone(ap->a_arg, ap->a_m, ap->a_reqpage, error);
error = VOP_GETPAGES(ap->a_vp, ap->a_m, ap->a_count, ap->a_rbehind,
ap->a_rahead);
ap->a_iodone(ap->a_arg, ap->a_m, ap->a_count, error);
return (error);
}

6
sys/kern/vnode_if.src
View File

@ -473,7 +473,8 @@ vop_getpages {
IN struct vnode *vp;
IN vm_page_t *m;
IN int count;
IN int reqpage;
IN int *rbehind;
IN int *rahead;
};
@ -483,7 +484,8 @@ vop_getpages_async {
IN struct vnode *vp;
IN vm_page_t *m;
IN int count;
IN int reqpage;
IN int *rbehind;
IN int *rahead;
IN vop_getpages_iodone_t *iodone;
IN void *arg;
};

13
sys/sys/buf.h
View File

@ -122,14 +122,13 @@ struct buf {
struct ucred *b_rcred; /* Read credentials reference. */
struct ucred *b_wcred; /* Write credentials reference. */
union {
TAILQ_ENTRY(buf) bu_freelist; /* (Q) */
TAILQ_ENTRY(buf) b_freelist; /* (Q) */
struct {
void (*pg_iodone)(void *, vm_page_t *, int, int);
int pg_reqpage;
} bu_pager;
} b_union;
#define b_freelist b_union.bu_freelist
#define b_pager b_union.bu_pager
void (*b_pgiodone)(void *, vm_page_t *, int, int);
int b_pgbefore;
int b_pgafter;
};
};
union cluster_info {
TAILQ_HEAD(cluster_list_head, buf) cluster_head;
TAILQ_ENTRY(buf) cluster_entry;

12
sys/vm/default_pager.c
View File

@ -56,7 +56,7 @@ __FBSDID("$FreeBSD$");
static vm_object_t default_pager_alloc(void *, vm_ooffset_t, vm_prot_t,
vm_ooffset_t, struct ucred *);
static void default_pager_dealloc(vm_object_t);
static int default_pager_getpages(vm_object_t, vm_page_t *, int, int);
static int default_pager_getpages(vm_object_t, vm_page_t *, int, int *, int *);
static void default_pager_putpages(vm_object_t, vm_page_t *, int,
boolean_t, int *);
static boolean_t default_pager_haspage(vm_object_t, vm_pindex_t, int *,
@ -122,13 +122,11 @@ default_pager_dealloc(object)
* see a vm_page with assigned swap here.
*/
static int
default_pager_getpages(object, m, count, reqpage)
vm_object_t object;
vm_page_t *m;
int count;
int reqpage;
default_pager_getpages(vm_object_t object, vm_page_t *m, int count,
int *rbehind, int *rahead)
{
return VM_PAGER_FAIL;
return (VM_PAGER_FAIL);
}
/*

23
sys/vm/device_pager.c
View File

@ -59,7 +59,7 @@ static void dev_pager_init(void);
static vm_object_t dev_pager_alloc(void *, vm_ooffset_t, vm_prot_t,
vm_ooffset_t, struct ucred *);
static void dev_pager_dealloc(vm_object_t);
static int dev_pager_getpages(vm_object_t, vm_page_t *, int, int);
static int dev_pager_getpages(vm_object_t, vm_page_t *, int, int *, int *);
static void dev_pager_putpages(vm_object_t, vm_page_t *, int, int, int *);
static boolean_t dev_pager_haspage(vm_object_t, vm_pindex_t, int *, int *);
static void dev_pager_free_page(vm_object_t object, vm_page_t m);
@ -257,28 +257,33 @@ dev_pager_dealloc(vm_object_t object)
}
static int
dev_pager_getpages(vm_object_t object, vm_page_t *ma, int count, int reqpage)
dev_pager_getpages(vm_object_t object, vm_page_t *ma, int count, int *rbehind,
int *rahead)
{
int error;
/* Since our haspage reports zero after/before, the count is 1. */
KASSERT(count == 1, ("%s: count %d", __func__, count));
VM_OBJECT_ASSERT_WLOCKED(object);
error = object->un_pager.devp.ops->cdev_pg_fault(object,
IDX_TO_OFF(ma[reqpage]->pindex), PROT_READ, &ma[reqpage]);
IDX_TO_OFF(ma[0]->pindex), PROT_READ, &ma[0]);
VM_OBJECT_ASSERT_WLOCKED(object);
vm_pager_free_nonreq(object, ma, reqpage, count, TRUE);
if (error == VM_PAGER_OK) {
KASSERT((object->type == OBJT_DEVICE &&
(ma[reqpage]->oflags & VPO_UNMANAGED) != 0) ||
(ma[0]->oflags & VPO_UNMANAGED) != 0) ||
(object->type == OBJT_MGTDEVICE &&
(ma[reqpage]->oflags & VPO_UNMANAGED) == 0),
("Wrong page type %p %p", ma[reqpage], object));
(ma[0]->oflags & VPO_UNMANAGED) == 0),
("Wrong page type %p %p", ma[0], object));
if (object->type == OBJT_DEVICE) {
TAILQ_INSERT_TAIL(&object->un_pager.devp.devp_pglist,
ma[reqpage], plinks.q);
ma[0], plinks.q);
}
if (rbehind)
*rbehind = 0;
if (rahead)
*rahead = 0;
}
return (error);

14
sys/vm/phys_pager.c
View File

@ -139,7 +139,8 @@ phys_pager_dealloc(vm_object_t object)
* Fill as many pages as vm_fault has allocated for us.
*/
static int
phys_pager_getpages(vm_object_t object, vm_page_t *m, int count, int reqpage)
phys_pager_getpages(vm_object_t object, vm_page_t *m, int count, int *rbehind,
int *rahead)
{
int i;
@ -154,14 +155,11 @@ phys_pager_getpages(vm_object_t object, vm_page_t *m, int count, int reqpage)
("phys_pager_getpages: partially valid page %p", m[i]));
KASSERT(m[i]->dirty == 0,
("phys_pager_getpages: dirty page %p", m[i]));
/* The requested page must remain busy, the others not. */
if (i == reqpage) {
vm_page_lock(m[i]);
vm_page_flash(m[i]);
vm_page_unlock(m[i]);
} else
vm_page_xunbusy(m[i]);
}
if (rbehind)
*rbehind = 0;
if (rahead)
*rahead = 0;
return (VM_PAGER_OK);
}

30
sys/vm/sg_pager.c
View File

@ -49,7 +49,7 @@ __FBSDID("$FreeBSD$");
static vm_object_t sg_pager_alloc(void *, vm_ooffset_t, vm_prot_t,
vm_ooffset_t, struct ucred *);
static void sg_pager_dealloc(vm_object_t);
static int sg_pager_getpages(vm_object_t, vm_page_t *, int, int);
static int sg_pager_getpages(vm_object_t, vm_page_t *, int, int *, int *);
static void sg_pager_putpages(vm_object_t, vm_page_t *, int,
boolean_t, int *);
static boolean_t sg_pager_haspage(vm_object_t, vm_pindex_t, int *,
@ -135,7 +135,8 @@ sg_pager_dealloc(vm_object_t object)
}
static int
sg_pager_getpages(vm_object_t object, vm_page_t *m, int count, int reqpage)
sg_pager_getpages(vm_object_t object, vm_page_t *m, int count, int *rbehind,
int *rahead)
{
struct sglist *sg;
vm_page_t m_paddr, page;
@ -145,11 +146,13 @@ sg_pager_getpages(vm_object_t object, vm_page_t *m, int count, int reqpage)
size_t space;
int i;
/* Since our haspage reports zero after/before, the count is 1. */
KASSERT(count == 1, ("%s: count %d", __func__, count));
VM_OBJECT_ASSERT_WLOCKED(object);
sg = object->handle;
memattr = object->memattr;
VM_OBJECT_WUNLOCK(object);
offset = m[reqpage]->pindex;
offset = m[0]->pindex;
/*
* Lookup the physical address of the requested page. An initial
@ -178,26 +181,23 @@ sg_pager_getpages(vm_object_t object, vm_page_t *m, int count, int reqpage)
}
/* Return a fake page for the requested page. */
KASSERT(!(m[reqpage]->flags & PG_FICTITIOUS),
KASSERT(!(m[0]->flags & PG_FICTITIOUS),
("backing page for SG is fake"));
/* Construct a new fake page. */
page = vm_page_getfake(paddr, memattr);
VM_OBJECT_WLOCK(object);
TAILQ_INSERT_TAIL(&object->un_pager.sgp.sgp_pglist, page, plinks.q);
/* Free the original pages and insert this fake page into the object. */
for (i = 0; i < count; i++) {
if (i == reqpage &&
vm_page_replace(page, object, offset) != m[i])
panic("sg_pager_getpages: invalid place replacement");
vm_page_lock(m[i]);
vm_page_free(m[i]);
vm_page_unlock(m[i]);
}
m[reqpage] = page;
if (vm_page_replace(page, object, offset) != m[0])
panic("sg_pager_getpages: invalid place replacement");
m[0] = page;
page->valid = VM_PAGE_BITS_ALL;
if (rbehind)
*rbehind = 0;
if (rahead)
*rahead = 0;
return (VM_PAGER_OK);
}

166
sys/vm/swap_pager.c
View File

@ -357,9 +357,10 @@ static vm_object_t
swap_pager_alloc(void *handle, vm_ooffset_t size,
vm_prot_t prot, vm_ooffset_t offset, struct ucred *);
static void swap_pager_dealloc(vm_object_t object);
static int swap_pager_getpages(vm_object_t, vm_page_t *, int, int);
static int swap_pager_getpages_async(vm_object_t, vm_page_t *, int, int,
pgo_getpages_iodone_t, void *);
static int swap_pager_getpages(vm_object_t, vm_page_t *, int, int *,
int *);
static int swap_pager_getpages_async(vm_object_t, vm_page_t *, int, int *,
int *, pgo_getpages_iodone_t, void *);
static void swap_pager_putpages(vm_object_t, vm_page_t *, int, boolean_t, int *);
static boolean_t
swap_pager_haspage(vm_object_t object, vm_pindex_t pindex, int *before, int *after);
@ -413,16 +414,6 @@ static void swp_pager_meta_free(vm_object_t, vm_pindex_t, daddr_t);
static void swp_pager_meta_free_all(vm_object_t);
static daddr_t swp_pager_meta_ctl(vm_object_t, vm_pindex_t, int);
static void
swp_pager_free_nrpage(vm_page_t m)
{
vm_page_lock(m);
if (m->wire_count == 0)
vm_page_free(m);
vm_page_unlock(m);
}
/*
* SWP_SIZECHECK() - update swap_pager_full indication
*
@ -1103,16 +1094,12 @@ swap_pager_unswapped(vm_page_t m)
* left busy, but the others adjusted.
*/
static int
swap_pager_getpages(vm_object_t object, vm_page_t *m, int count, int reqpage)
swap_pager_getpages(vm_object_t object, vm_page_t *m, int count, int *rbehind,
int *rahead)
{
struct buf *bp;
vm_page_t mreq;
int i;
int j;
daddr_t blk;
mreq = m[reqpage];
/*
* Calculate range to retrieve. The pages have already been assigned
* their swapblks. We require a *contiguous* range but we know it to
@ -1122,45 +1109,18 @@ swap_pager_getpages(vm_object_t object, vm_page_t *m, int count, int reqpage)
*
* The swp_*() calls must be made with the object locked.
*/
blk = swp_pager_meta_ctl(mreq->object, mreq->pindex, 0);
blk = swp_pager_meta_ctl(m[0]->object, m[0]->pindex, 0);
for (i = reqpage - 1; i >= 0; --i) {
daddr_t iblk;
iblk = swp_pager_meta_ctl(m[i]->object, m[i]->pindex, 0);
if (blk != iblk + (reqpage - i))
break;
}
++i;
for (j = reqpage + 1; j < count; ++j) {
daddr_t jblk;
jblk = swp_pager_meta_ctl(m[j]->object, m[j]->pindex, 0);
if (blk != jblk - (j - reqpage))
break;
}
/*
* free pages outside our collection range. Note: we never free
* mreq, it must remain busy throughout.
*/
if (0 < i || j < count) {
int k;
for (k = 0; k < i; ++k)
swp_pager_free_nrpage(m[k]);
for (k = j; k < count; ++k)
swp_pager_free_nrpage(m[k]);
}
/*
* Return VM_PAGER_FAIL if we have nothing to do. Return mreq
* still busy, but the others unbusied.
*/
if (blk == SWAPBLK_NONE)
return (VM_PAGER_FAIL);
#ifdef INVARIANTS
for (int i = 0; i < count; i++)
KASSERT(blk + i ==
swp_pager_meta_ctl(m[i]->object, m[i]->pindex, 0),
("%s: range is not contiguous", __func__));
#endif
/*
* Getpbuf() can sleep.
*/
@ -1175,21 +1135,16 @@ swap_pager_getpages(vm_object_t object, vm_page_t *m, int count, int reqpage)
bp->b_iodone = swp_pager_async_iodone;
bp->b_rcred = crhold(thread0.td_ucred);
bp->b_wcred = crhold(thread0.td_ucred);
bp->b_blkno = blk - (reqpage - i);
bp->b_bcount = PAGE_SIZE * (j - i);
bp->b_bufsize = PAGE_SIZE * (j - i);
bp->b_pager.pg_reqpage = reqpage - i;
bp->b_blkno = blk;
bp->b_bcount = PAGE_SIZE * count;
bp->b_bufsize = PAGE_SIZE * count;
bp->b_npages = count;
VM_OBJECT_WLOCK(object);
{
int k;
for (k = i; k < j; ++k) {
bp->b_pages[k - i] = m[k];
m[k]->oflags |= VPO_SWAPINPROG;
}
for (int i = 0; i < count; i++) {
bp->b_pages[i] = m[i];
m[i]->oflags |= VPO_SWAPINPROG;
}
bp->b_npages = j - i;
PCPU_INC(cnt.v_swapin);
PCPU_ADD(cnt.v_swappgsin, bp->b_npages);
@ -1221,8 +1176,8 @@ swap_pager_getpages(vm_object_t object, vm_page_t *m, int count, int reqpage)
* is set in the meta-data.
*/
VM_OBJECT_WLOCK(object);
while ((mreq->oflags & VPO_SWAPINPROG) != 0) {
mreq->oflags |= VPO_SWAPSLEEP;
while ((m[0]->oflags & VPO_SWAPINPROG) != 0) {
m[0]->oflags |= VPO_SWAPSLEEP;
PCPU_INC(cnt.v_intrans);
if (VM_OBJECT_SLEEP(object, &object->paging_in_progress, PSWP,
"swread", hz * 20)) {
@ -1233,15 +1188,18 @@ swap_pager_getpages(vm_object_t object, vm_page_t *m, int count, int reqpage)
}
/*
* mreq is left busied after completion, but all the other pages
* are freed. If we had an unrecoverable read error the page will
* not be valid.
* If we had an unrecoverable read error pages will not be valid.
*/
if (mreq->valid != VM_PAGE_BITS_ALL) {
return (VM_PAGER_ERROR);
} else {
return (VM_PAGER_OK);
}
for (int i = 0; i < count; i++)
if (m[i]->valid != VM_PAGE_BITS_ALL)
return (VM_PAGER_ERROR);
if (rbehind)
*rbehind = 0;
if (rahead)
*rahead = 0;
return (VM_PAGER_OK);
/*
* A final note: in a low swap situation, we cannot deallocate swap
@ -1259,11 +1217,11 @@ swap_pager_getpages(vm_object_t object, vm_page_t *m, int count, int reqpage)
*/
static int
swap_pager_getpages_async(vm_object_t object, vm_page_t *m, int count,
int reqpage, pgo_getpages_iodone_t iodone, void *arg)
int *rbehind, int *rahead, pgo_getpages_iodone_t iodone, void *arg)
{
int r, error;
r = swap_pager_getpages(object, m, count, reqpage);
r = swap_pager_getpages(object, m, count, rbehind, rahead);
VM_OBJECT_WUNLOCK(object);
switch (r) {
case VM_PAGER_OK:
@ -1527,33 +1485,11 @@ swp_pager_async_iodone(struct buf *bp)
*/
if (bp->b_iocmd == BIO_READ) {
/*
* When reading, reqpage needs to stay
* locked for the parent, but all other
* pages can be freed. We still want to
* wakeup the parent waiting on the page,
* though. ( also: pg_reqpage can be -1 and
* not match anything ).
*
* We have to wake specifically requested pages
* up too because we cleared VPO_SWAPINPROG and
* someone may be waiting for that.
*
* NOTE: for reads, m->dirty will probably
* be overridden by the original caller of
* getpages so don't play cute tricks here.
*/
m->valid = 0;
if (i != bp->b_pager.pg_reqpage)
swp_pager_free_nrpage(m);
else {
vm_page_lock(m);
vm_page_flash(m);
vm_page_unlock(m);
}
/*
* If i == bp->b_pager.pg_reqpage, do not wake
* the page up. The caller needs to.
*/
} else {
/*
* If a write error occurs, reactivate page
@ -1575,38 +1511,12 @@ swp_pager_async_iodone(struct buf *bp)
* want to do that anyway, but it was an optimization
* that existed in the old swapper for a time before
* it got ripped out due to precisely this problem.
*
* If not the requested page then deactivate it.
*
* Note that the requested page, reqpage, is left
* busied, but we still have to wake it up. The
* other pages are released (unbusied) by
* vm_page_xunbusy().
*/
KASSERT(!pmap_page_is_mapped(m),
("swp_pager_async_iodone: page %p is mapped", m));
m->valid = VM_PAGE_BITS_ALL;
KASSERT(m->dirty == 0,
("swp_pager_async_iodone: page %p is dirty", m));
/*
* We have to wake specifically requested pages
* up too because we cleared VPO_SWAPINPROG and
* could be waiting for it in getpages. However,
* be sure to not unbusy getpages specifically
* requested page - getpages expects it to be
* left busy.
*/
if (i != bp->b_pager.pg_reqpage) {
vm_page_lock(m);
vm_page_deactivate(m);
vm_page_unlock(m);
vm_page_xunbusy(m);
} else {
vm_page_lock(m);
vm_page_flash(m);
vm_page_unlock(m);
}
m->valid = VM_PAGE_BITS_ALL;
} else {
/*
* For write success, clear the dirty
@ -1727,7 +1637,7 @@ swp_pager_force_pagein(vm_object_t object, vm_pindex_t pindex)
return;
}
if (swap_pager_getpages(object, &m, 1, 0) != VM_PAGER_OK)
if (swap_pager_getpages(object, &m, 1, NULL, NULL) != VM_PAGER_OK)
panic("swap_pager_force_pagein: read from swap failed");/*XXX*/
vm_object_pip_wakeup(object);
vm_page_dirty(m);

196
sys/vm/vm_fault.c
View File

@ -107,13 +107,8 @@ __FBSDID("$FreeBSD$");
#define PFBAK 4
#define PFFOR 4
static int vm_fault_additional_pages(vm_page_t, int, int, vm_page_t *, int *);
#define VM_FAULT_READ_BEHIND 8
#define VM_FAULT_READ_DEFAULT (1 + VM_FAULT_READ_AHEAD_INIT)
#define VM_FAULT_READ_MAX (1 + VM_FAULT_READ_AHEAD_MAX)
#define VM_FAULT_NINCR (VM_FAULT_READ_MAX / VM_FAULT_READ_BEHIND)
#define VM_FAULT_SUM (VM_FAULT_NINCR * (VM_FAULT_NINCR + 1) / 2)
#define VM_FAULT_DONTNEED_MIN 1048576
@ -133,7 +128,7 @@ struct faultstate {
static void vm_fault_dontneed(const struct faultstate *fs, vm_offset_t vaddr,
int ahead);
static void vm_fault_prefault(const struct faultstate *fs, vm_offset_t addra,
int faultcount, int reqpage);
int backward, int forward);
static inline void
release_page(struct faultstate *fs)
@ -288,11 +283,10 @@ vm_fault_hold(vm_map_t map, vm_offset_t vaddr, vm_prot_t fault_type,
int fault_flags, vm_page_t *m_hold)
{
vm_prot_t prot;
int alloc_req, era, faultcount, nera, reqpage, result;
int alloc_req, era, faultcount, nera, result;
boolean_t growstack, is_first_object_locked, wired;
int map_generation;
vm_object_t next_object;
vm_page_t marray[VM_FAULT_READ_MAX];
int hardfault;
struct faultstate fs;
struct vnode *vp;
@ -303,7 +297,7 @@ vm_fault_hold(vm_map_t map, vm_offset_t vaddr, vm_prot_t fault_type,
growstack = TRUE;
PCPU_INC(cnt.v_vm_faults);
fs.vp = NULL;
faultcount = reqpage = 0;
faultcount = 0;
RetryFault:;
@ -389,7 +383,7 @@ RetryFault:;
FALSE);
VM_OBJECT_RUNLOCK(fs.first_object);
if (!wired)
vm_fault_prefault(&fs, vaddr, 0, 0);
vm_fault_prefault(&fs, vaddr, PFBAK, PFFOR);
vm_map_lookup_done(fs.map, fs.entry);
curthread->td_ru.ru_minflt++;
return (KERN_SUCCESS);
@ -652,36 +646,13 @@ RetryFault:;
("vm_fault: vnode-backed object mapped by system map"));
/*
* now we find out if any other pages should be paged
* in at this time this routine checks to see if the
* pages surrounding this fault reside in the same
* object as the page for this fault. If they do,
* then they are faulted in also into the object. The
* array "marray" returned contains an array of
* vm_page_t structs where one of them is the
* vm_page_t passed to the routine. The reqpage
* return value is the index into the marray for the
* vm_page_t passed to the routine.
*
* fs.m plus the additional pages are exclusive busied.
* Page in the requested page and hint the pager,
* that it may bring up surrounding pages.
*/
faultcount = vm_fault_additional_pages(
fs.m, behind, ahead, marray, &reqpage);
rv = faultcount ?
vm_pager_get_pages(fs.object, marray, faultcount,
reqpage) : VM_PAGER_FAIL;
rv = vm_pager_get_pages(fs.object, &fs.m, 1,
&behind, &ahead);
if (rv == VM_PAGER_OK) {
/*
* Found the page. Leave it busy while we play
* with it.
*
* Pager could have changed the page. Pager
* is responsible for disposition of old page
* if moved.
*/
fs.m = marray[reqpage];
faultcount = behind + 1 + ahead;
hardfault++;
break; /* break to PAGE HAS BEEN FOUND */
}
@ -965,16 +936,13 @@ RetryFault:;
}
/*
* If the page was filled by a pager, update the map entry's
* last read offset. Since the pager does not return the
* actual set of pages that it read, this update is based on
* the requested set. Typically, the requested and actual
* sets are the same.
* last read offset.
*
* XXX The following assignment modifies the map
* without holding a write lock on it.
*/
if (hardfault)
fs.entry->next_read = fs.pindex + faultcount - reqpage;
fs.entry->next_read = fs.pindex + ahead + 1;
vm_fault_dirty(fs.entry, fs.m, prot, fault_type, fault_flags, TRUE);
vm_page_assert_xbusied(fs.m);
@ -997,7 +965,9 @@ RetryFault:;
fault_type | (wired ? PMAP_ENTER_WIRED : 0), 0);
if (faultcount != 1 && (fault_flags & VM_FAULT_WIRE) == 0 &&
wired == 0)
vm_fault_prefault(&fs, vaddr, faultcount, reqpage);
vm_fault_prefault(&fs, vaddr,
faultcount > 0 ? behind : PFBAK,
faultcount > 0 ? ahead : PFFOR);
VM_OBJECT_WLOCK(fs.object);
vm_page_lock(fs.m);
@ -1114,7 +1084,7 @@ vm_fault_dontneed(const struct faultstate *fs, vm_offset_t vaddr, int ahead)
*/
static void
vm_fault_prefault(const struct faultstate *fs, vm_offset_t addra,
int faultcount, int reqpage)
int backward, int forward)
{
pmap_t pmap;
vm_map_entry_t entry;
@ -1122,19 +1092,12 @@ vm_fault_prefault(const struct faultstate *fs, vm_offset_t addra,
vm_offset_t addr, starta;
vm_pindex_t pindex;
vm_page_t m;
int backward, forward, i;
int i;
pmap = fs->map->pmap;
if (pmap != vmspace_pmap(curthread->td_proc->p_vmspace))
return;
if (faultcount > 0) {
backward = reqpage;
forward = faultcount - reqpage - 1;
} else {
backward = PFBAK;
forward = PFFOR;
}
entry = fs->entry;
starta = addra - backward * PAGE_SIZE;
@ -1465,133 +1428,6 @@ vm_fault_copy_entry(vm_map_t dst_map, vm_map_t src_map,
}
}
/*
* This routine checks around the requested page for other pages that
* might be able to be faulted in. This routine brackets the viable
* pages for the pages to be paged in.
*
* Inputs:
* m, rbehind, rahead
*
* Outputs:
* marray (array of vm_page_t), reqpage (index of requested page)
*
* Return value:
* number of pages in marray
*/
static int
vm_fault_additional_pages(m, rbehind, rahead, marray, reqpage)
vm_page_t m;
int rbehind;
int rahead;
vm_page_t *marray;
int *reqpage;
{
int i,j;
vm_object_t object;
vm_pindex_t pindex, startpindex, endpindex, tpindex;
vm_page_t rtm;
int cbehind, cahead;
VM_OBJECT_ASSERT_WLOCKED(m->object);
object = m->object;
pindex = m->pindex;
cbehind = cahead = 0;
/*
* if the requested page is not available, then give up now
*/
if (!vm_pager_has_page(object, pindex, &cbehind, &cahead)) {
return 0;
}
if ((cbehind == 0) && (cahead == 0)) {
*reqpage = 0;
marray[0] = m;
return 1;
}
if (rahead > cahead) {
rahead = cahead;
}
if (rbehind > cbehind) {
rbehind = cbehind;
}
/*
* scan backward for the read behind pages -- in memory
*/
if (pindex > 0) {
if (rbehind > pindex) {
rbehind = pindex;
startpindex = 0;
} else {
startpindex = pindex - rbehind;
}
if ((rtm = TAILQ_PREV(m, pglist, listq)) != NULL &&
rtm->pindex >= startpindex)
startpindex = rtm->pindex + 1;
/* tpindex is unsigned; beware of numeric underflow. */
for (i = 0, tpindex = pindex - 1; tpindex >= startpindex &&
tpindex < pindex; i++, tpindex--) {
rtm = vm_page_alloc(object, tpindex, VM_ALLOC_NORMAL |
VM_ALLOC_IFNOTCACHED);
if (rtm == NULL) {
/*
* Shift the allocated pages to the
* beginning of the array.
*/
for (j = 0; j < i; j++) {
marray[j] = marray[j + tpindex + 1 -
startpindex];
}
break;
}
marray[tpindex - startpindex] = rtm;
}
} else {
startpindex = 0;
i = 0;
}
marray[i] = m;
/* page offset of the required page */
*reqpage = i;
tpindex = pindex + 1;
i++;
/*
* scan forward for the read ahead pages
*/
endpindex = tpindex + rahead;
if ((rtm = TAILQ_NEXT(m, listq)) != NULL && rtm->pindex < endpindex)
endpindex = rtm->pindex;
if (endpindex > object->size)
endpindex = object->size;
for (; tpindex < endpindex; i++, tpindex++) {
rtm = vm_page_alloc(object, tpindex, VM_ALLOC_NORMAL |
VM_ALLOC_IFNOTCACHED);
if (rtm == NULL) {
break;
}
marray[i] = rtm;
}
/* return number of pages */
return i;
}
/*
* Block entry into the machine-independent layer's page fault handler by
* the calling thread. Subsequent calls to vm_fault() by that thread will

50
sys/vm/vm_glue.c
View File

@ -238,7 +238,7 @@ vm_imgact_hold_page(vm_object_t object, vm_ooffset_t offset)
pindex = OFF_TO_IDX(offset);
m = vm_page_grab(object, pindex, VM_ALLOC_NORMAL);
if (m->valid != VM_PAGE_BITS_ALL) {
rv = vm_pager_get_pages(object, &m, 1, 0);
rv = vm_pager_get_pages(object, &m, 1, NULL, NULL);
if (rv != VM_PAGER_OK) {
vm_page_lock(m);
vm_page_free(m);
@ -567,37 +567,37 @@ vm_thread_swapin(struct thread *td)
{
vm_object_t ksobj;
vm_page_t ma[KSTACK_MAX_PAGES];
int i, j, pages, rv;
int pages;
pages = td->td_kstack_pages;
ksobj = td->td_kstack_obj;
VM_OBJECT_WLOCK(ksobj);
for (i = 0; i < pages; i++)
for (int i = 0; i < pages; i++)
ma[i] = vm_page_grab(ksobj, i, VM_ALLOC_NORMAL |
VM_ALLOC_WIRED);
for (i = 0; i < pages; i++) {
if (ma[i]->valid != VM_PAGE_BITS_ALL) {
vm_page_assert_xbusied(ma[i]);
vm_object_pip_add(ksobj, 1);
for (j = i + 1; j < pages; j++) {
if (ma[j]->valid != VM_PAGE_BITS_ALL)
vm_page_assert_xbusied(ma[j]);
if (ma[j]->valid == VM_PAGE_BITS_ALL)
break;
}
rv = vm_pager_get_pages(ksobj, ma + i, j - i, 0);
if (rv != VM_PAGER_OK)
panic("vm_thread_swapin: cannot get kstack for proc: %d",
td->td_proc->p_pid);
/*
* All pages in the array are in place, due to the
* pager is always the swap pager, which doesn't
* free or remove wired non-req pages from object.
*/
vm_object_pip_wakeup(ksobj);
vm_page_xunbusy(ma[i]);
} else if (vm_page_xbusied(ma[i]))
for (int i = 0; i < pages;) {
int j, a, count, rv;
vm_page_assert_xbusied(ma[i]);
if (ma[i]->valid == VM_PAGE_BITS_ALL) {
vm_page_xunbusy(ma[i]);
i++;
continue;
}
vm_object_pip_add(ksobj, 1);
for (j = i + 1; j < pages; j++)
if (ma[j]->valid == VM_PAGE_BITS_ALL)
break;
rv = vm_pager_has_page(ksobj, ma[i]->pindex, NULL, &a);
KASSERT(rv == 1, ("%s: missing page %p", __func__, ma[i]));
count = min(a + 1, j - i);
rv = vm_pager_get_pages(ksobj, ma + i, count, NULL, NULL);
KASSERT(rv == VM_PAGER_OK, ("%s: cannot get kstack for proc %d",
__func__, td->td_proc->p_pid));
vm_object_pip_wakeup(ksobj);
for (j = i; j < i + count; j++)
vm_page_xunbusy(ma[j]);
i += count;
}
VM_OBJECT_WUNLOCK(ksobj);
pmap_qenter(td->td_kstack, ma, pages);

2
sys/vm/vm_object.c
View File

@ -2014,7 +2014,7 @@ vm_object_populate(vm_object_t object, vm_pindex_t start, vm_pindex_t end)
for (pindex = start; pindex < end; pindex++) {
m = vm_page_grab(object, pindex, VM_ALLOC_NORMAL);
if (m->valid != VM_PAGE_BITS_ALL) {
rv = vm_pager_get_pages(object, &m, 1, 0);
rv = vm_pager_get_pages(object, &m, 1, NULL, NULL);
if (rv != VM_PAGER_OK) {
vm_page_lock(m);
vm_page_free(m);

2
sys/vm/vm_object.h
View File

@ -243,6 +243,8 @@ extern struct vm_object kmem_object_store;
rw_try_upgrade(&(object)->lock)
#define VM_OBJECT_WLOCK(object) \
rw_wlock(&(object)->lock)
#define VM_OBJECT_WOWNED(object) \
rw_wowned(&(object)->lock)
#define VM_OBJECT_WUNLOCK(object) \
rw_wunlock(&(object)->lock)

44
sys/vm/vm_page.c
View File

@ -979,38 +979,28 @@ vm_page_free_zero(vm_page_t m)
/*
* Unbusy and handle the page queueing for a page from the VOP_GETPAGES()
* array which is not the request page.
* array which was optionally read ahead or behind.
*/
void
vm_page_readahead_finish(vm_page_t m)
{
if (m->valid != 0) {
/*
* Since the page is not the requested page, whether
* it should be activated or deactivated is not
* obvious. Empirical results have shown that
* deactivating the page is usually the best choice,
* unless the page is wanted by another thread.
*/
vm_page_lock(m);
if ((m->busy_lock & VPB_BIT_WAITERS) != 0)
vm_page_activate(m);
else
vm_page_deactivate(m);
vm_page_unlock(m);
vm_page_xunbusy(m);
} else {
/*
* Free the completely invalid page. Such page state
* occurs due to the short read operation which did
* not covered our page at all, or in case when a read
* error happens.
*/
vm_page_lock(m);
vm_page_free(m);
vm_page_unlock(m);
}
/* We shouldn't put invalid pages on queues. */
KASSERT(m->valid != 0, ("%s: %p is invalid", __func__, m));
/*
* Since the page is not the actually needed one, whether it should
* be activated or deactivated is not obvious. Empirical results
* have shown that deactivating the page is usually the best choice,
* unless the page is wanted by another thread.
*/
vm_page_lock(m);
if ((m->busy_lock & VPB_BIT_WAITERS) != 0)
vm_page_activate(m);
else
vm_page_deactivate(m);
vm_page_unlock(m);
vm_page_xunbusy(m);
}
/*

89
sys/vm/vm_pager.c
View File

@ -88,7 +88,7 @@ int cluster_pbuf_freecnt = -1; /* unlimited to begin with */
struct buf *swbuf;
static int dead_pager_getpages(vm_object_t, vm_page_t *, int, int);
static int dead_pager_getpages(vm_object_t, vm_page_t *, int, int *, int *);
static vm_object_t dead_pager_alloc(void *, vm_ooffset_t, vm_prot_t,
vm_ooffset_t, struct ucred *);
static void dead_pager_putpages(vm_object_t, vm_page_t *, int, int, int *);
@ -96,13 +96,11 @@ static boolean_t dead_pager_haspage(vm_object_t, vm_pindex_t, int *, int *);
static void dead_pager_dealloc(vm_object_t);
static int
dead_pager_getpages(obj, ma, count, req)
vm_object_t obj;
vm_page_t *ma;
int count;
int req;
dead_pager_getpages(vm_object_t obj, vm_page_t *ma, int count, int *rbehind,
int *rahead)
{
return VM_PAGER_FAIL;
return (VM_PAGER_FAIL);
}
static vm_object_t
@ -282,45 +280,47 @@ vm_pager_assert_in(vm_object_t object, vm_page_t *m, int count)
* The requested page must be fully valid on successful return.
*/
int
vm_pager_get_pages(vm_object_t object, vm_page_t *m, int count, int reqpage)
vm_pager_get_pages(vm_object_t object, vm_page_t *m, int count, int *rbehind,
int *rahead)
{
#ifdef INVARIANTS
vm_pindex_t pindex = m[0]->pindex;
#endif
int r;
vm_pager_assert_in(object, m, count);
r = (*pagertab[object->type]->pgo_getpages)(object, m, count, reqpage);
r = (*pagertab[object->type]->pgo_getpages)(object, m, count, rbehind,
rahead);
if (r != VM_PAGER_OK)
return (r);
/*
* If pager has replaced the page, assert that it had
* updated the array. Also assert that page is still
* busied.
*/
KASSERT(m[reqpage] == vm_page_lookup(object, m[reqpage]->pindex),
("%s: mismatch page %p pindex %ju", __func__,
m[reqpage], (uintmax_t )m[reqpage]->pindex));
vm_page_assert_xbusied(m[reqpage]);
/*
* Pager didn't fill up entire page. Zero out
* partially filled data.
*/
if (m[reqpage]->valid != VM_PAGE_BITS_ALL)
vm_page_zero_invalid(m[reqpage], TRUE);
for (int i = 0; i < count; i++) {
/*
* If pager has replaced a page, assert that it had
* updated the array.
*/
KASSERT(m[i] == vm_page_lookup(object, pindex++),
("%s: mismatch page %p pindex %ju", __func__,
m[i], (uintmax_t )pindex - 1));
/*
* Zero out partially filled data.
*/
if (m[i]->valid != VM_PAGE_BITS_ALL)
vm_page_zero_invalid(m[i], TRUE);
}
return (VM_PAGER_OK);
}
int
vm_pager_get_pages_async(vm_object_t object, vm_page_t *m, int count,
int reqpage, pgo_getpages_iodone_t iodone, void *arg)
int *rbehind, int *rahead, pgo_getpages_iodone_t iodone, void *arg)
{
vm_pager_assert_in(object, m, count);
return ((*pagertab[object->type]->pgo_getpages_async)(object, m,
count, reqpage, iodone, arg));
count, rbehind, rahead, iodone, arg));
}
/*
@ -354,39 +354,6 @@ vm_pager_object_lookup(struct pagerlst *pg_list, void *handle)
return (object);
}
/*
* Free the non-requested pages from the given array. To remove all pages,
* caller should provide out of range reqpage number.
*/
void
vm_pager_free_nonreq(vm_object_t object, vm_page_t ma[], int reqpage,
int npages, boolean_t object_locked)
{
enum { UNLOCKED, CALLER_LOCKED, INTERNALLY_LOCKED } locked;
int i;
if (object_locked) {
VM_OBJECT_ASSERT_WLOCKED(object);
locked = CALLER_LOCKED;
} else {
VM_OBJECT_ASSERT_UNLOCKED(object);
locked = UNLOCKED;
}
for (i = 0; i < npages; ++i) {
if (i != reqpage) {
if (locked == UNLOCKED) {
VM_OBJECT_WLOCK(object);
locked = INTERNALLY_LOCKED;
}
vm_page_lock(ma[i]);
vm_page_free(ma[i]);
vm_page_unlock(ma[i]);
}
}
if (locked == INTERNALLY_LOCKED)
VM_OBJECT_WUNLOCK(object);
}
/*
* initialize a physical buffer
*/

10
sys/vm/vm_pager.h
View File

@ -50,9 +50,9 @@ typedef void pgo_init_t(void);
typedef vm_object_t pgo_alloc_t(void *, vm_ooffset_t, vm_prot_t, vm_ooffset_t,
struct ucred *);
typedef void pgo_dealloc_t(vm_object_t);
typedef int pgo_getpages_t(vm_object_t, vm_page_t *, int, int);
typedef int pgo_getpages_t(vm_object_t, vm_page_t *, int, int *, int *);
typedef void pgo_getpages_iodone_t(void *, vm_page_t *, int, int);
typedef int pgo_getpages_async_t(vm_object_t, vm_page_t *, int, int,
typedef int pgo_getpages_async_t(vm_object_t, vm_page_t *, int, int *, int *,
pgo_getpages_iodone_t, void *);
typedef void pgo_putpages_t(vm_object_t, vm_page_t *, int, int, int *);
typedef boolean_t pgo_haspage_t(vm_object_t, vm_pindex_t, int *, int *);
@ -106,14 +106,12 @@ vm_object_t vm_pager_allocate(objtype_t, void *, vm_ooffset_t, vm_prot_t,
vm_ooffset_t, struct ucred *);
void vm_pager_bufferinit(void);
void vm_pager_deallocate(vm_object_t);
int vm_pager_get_pages(vm_object_t, vm_page_t *, int, int);
int vm_pager_get_pages_async(vm_object_t, vm_page_t *, int, int,
int vm_pager_get_pages(vm_object_t, vm_page_t *, int, int *, int *);
int vm_pager_get_pages_async(vm_object_t, vm_page_t *, int, int *, int *,
pgo_getpages_iodone_t, void *);
static __inline boolean_t vm_pager_has_page(vm_object_t, vm_pindex_t, int *, int *);
void vm_pager_init(void);
vm_object_t vm_pager_object_lookup(struct pagerlst *, void *);
void vm_pager_free_nonreq(vm_object_t object, vm_page_t ma[], int reqpage,
int npages, boolean_t object_locked);
static __inline void
vm_pager_put_pages(

370
sys/vm/vnode_pager.c
View File

@ -84,11 +84,9 @@ static int vnode_pager_addr(struct vnode *vp, vm_ooffset_t address,
static int vnode_pager_input_smlfs(vm_object_t object, vm_page_t m);
static int vnode_pager_input_old(vm_object_t object, vm_page_t m);
static void vnode_pager_dealloc(vm_object_t);
static int vnode_pager_local_getpages0(struct vnode *, vm_page_t *, int, int,
vop_getpages_iodone_t, void *);
static int vnode_pager_getpages(vm_object_t, vm_page_t *, int, int);
static int vnode_pager_getpages_async(vm_object_t, vm_page_t *, int, int,
vop_getpages_iodone_t, void *);
static int vnode_pager_getpages(vm_object_t, vm_page_t *, int, int *, int *);
static int vnode_pager_getpages_async(vm_object_t, vm_page_t *, int, int *,
int *, vop_getpages_iodone_t, void *);
static void vnode_pager_putpages(vm_object_t, vm_page_t *, int, int, int *);
static boolean_t vnode_pager_haspage(vm_object_t, vm_pindex_t, int *, int *);
static vm_object_t vnode_pager_alloc(void *, vm_ooffset_t, vm_prot_t,
@ -673,15 +671,15 @@ vnode_pager_input_old(vm_object_t object, vm_page_t m)
* backing vp's VOP_GETPAGES.
*/
static int
vnode_pager_getpages(vm_object_t object, vm_page_t *m, int count, int reqpage)
vnode_pager_getpages(vm_object_t object, vm_page_t *m, int count, int *rbehind,
int *rahead)
{
int rtval;
struct vnode *vp;
int bytes = count * PAGE_SIZE;
int rtval;
vp = object->handle;
VM_OBJECT_WUNLOCK(object);
rtval = VOP_GETPAGES(vp, m, bytes, reqpage);
rtval = VOP_GETPAGES(vp, m, count, rbehind, rahead);
KASSERT(rtval != EOPNOTSUPP,
("vnode_pager: FS getpages not implemented\n"));
VM_OBJECT_WLOCK(object);
@ -690,15 +688,14 @@ vnode_pager_getpages(vm_object_t object, vm_page_t *m, int count, int reqpage)
static int
vnode_pager_getpages_async(vm_object_t object, vm_page_t *m, int count,
int reqpage, vop_getpages_iodone_t iodone, void *arg)
int *rbehind, int *rahead, vop_getpages_iodone_t iodone, void *arg)
{
struct vnode *vp;
int rtval;
vp = object->handle;
VM_OBJECT_WUNLOCK(object);
rtval = VOP_GETPAGES_ASYNC(vp, m, count * PAGE_SIZE, reqpage,
iodone, arg);
rtval = VOP_GETPAGES_ASYNC(vp, m, count, rbehind, rahead, iodone, arg);
KASSERT(rtval != EOPNOTSUPP,
("vnode_pager: FS getpages_async not implemented\n"));
VM_OBJECT_WLOCK(object);
@ -714,48 +711,16 @@ int
vnode_pager_local_getpages(struct vop_getpages_args *ap)
{
return (vnode_pager_local_getpages0(ap->a_vp, ap->a_m, ap->a_count,
ap->a_reqpage, NULL, NULL));
return (vnode_pager_generic_getpages(ap->a_vp, ap->a_m, ap->a_count,
ap->a_rbehind, ap->a_rahead, NULL, NULL));
}
int
vnode_pager_local_getpages_async(struct vop_getpages_async_args *ap)
{
return (vnode_pager_local_getpages0(ap->a_vp, ap->a_m, ap->a_count,
ap->a_reqpage, ap->a_iodone, ap->a_arg));
}
static int
vnode_pager_local_getpages0(struct vnode *vp, vm_page_t *m, int bytecount,
int reqpage, vop_getpages_iodone_t iodone, void *arg)
{
vm_page_t mreq;
mreq = m[reqpage];
/*
* Since the caller has busied the requested page, that page's valid
* field will not be changed by other threads.
*/
vm_page_assert_xbusied(mreq);
/*
* The requested page has valid blocks. Invalid part can only
* exist at the end of file, and the page is made fully valid
* by zeroing in vm_pager_get_pages(). Free non-requested
* pages, since no i/o is done to read its content.
*/
if (mreq->valid != 0) {
vm_pager_free_nonreq(mreq->object, m, reqpage,
round_page(bytecount) / PAGE_SIZE, FALSE);
if (iodone != NULL)
iodone(arg, m, reqpage, 0);
return (VM_PAGER_OK);
}
return (vnode_pager_generic_getpages(vp, m, bytecount, reqpage,
iodone, arg));
return (vnode_pager_generic_getpages(ap->a_vp, ap->a_m, ap->a_count,
ap->a_rbehind, ap->a_rahead, ap->a_iodone, ap->a_arg));
}
/*
@ -763,25 +728,43 @@ vnode_pager_local_getpages0(struct vnode *vp, vm_page_t *m, int bytecount,
* own vnodes if they fail to implement VOP_GETPAGES.
*/
int
vnode_pager_generic_getpages(struct vnode *vp, vm_page_t *m, int bytecount,
int reqpage, vop_getpages_iodone_t iodone, void *arg)
vnode_pager_generic_getpages(struct vnode *vp, vm_page_t *m, int count,
int *a_rbehind, int *a_rahead, vop_getpages_iodone_t iodone, void *arg)
{
vm_object_t object;
struct bufobj *bo;
struct buf *bp;
daddr_t firstaddr, reqblock;
off_t foff, pib;
int pbefore, pafter, i, size, bsize, first, last, *freecnt;
int count, error, before, after, secmask;
off_t foff;
int bsize, pagesperblock, *freecnt;
int error, before, after, rbehind, rahead, poff, i;
int bytecount, secmask;
KASSERT(vp->v_type != VCHR && vp->v_type != VBLK,
("vnode_pager_generic_getpages does not support devices"));
("%s does not support devices", __func__));
if (vp->v_iflag & VI_DOOMED)
return (VM_PAGER_BAD);
object = vp->v_object;
count = bytecount / PAGE_SIZE;
foff = IDX_TO_OFF(m[0]->pindex);
bsize = vp->v_mount->mnt_stat.f_iosize;
pagesperblock = bsize / PAGE_SIZE;
KASSERT(foff < object->un_pager.vnp.vnp_size,
("%s: page %p offset beyond vp %p size", __func__, m[0], vp));
KASSERT(count <= sizeof(bp->b_pages),
("%s: requested %d pages", __func__, count));
/*
* The last page has valid blocks. Invalid part can only
* exist at the end of file, and the page is made fully valid
* by zeroing in vm_pager_get_pages().
*/
if (m[count - 1]->valid != 0 && --count == 0) {
if (iodone != NULL)
iodone(arg, m, 1, 0);
return (VM_PAGER_OK);
}
/*
* Synchronous and asynchronous paging operations use different
@ -800,130 +783,182 @@ vnode_pager_generic_getpages(struct vnode *vp, vm_page_t *m, int bytecount,
* If the file system doesn't support VOP_BMAP, use old way of
* getting pages via VOP_READ.
*/
error = VOP_BMAP(vp, IDX_TO_OFF(m[reqpage]->pindex) / bsize, &bo,
&reqblock, &after, &before);
error = VOP_BMAP(vp, foff / bsize, &bo, &bp->b_blkno, &after, &before);
if (error == EOPNOTSUPP) {
relpbuf(bp, freecnt);
VM_OBJECT_WLOCK(object);
for (i = 0; i < count; i++)
if (i != reqpage) {
vm_page_lock(m[i]);
vm_page_free(m[i]);
vm_page_unlock(m[i]);
}
PCPU_INC(cnt.v_vnodein);
PCPU_INC(cnt.v_vnodepgsin);
error = vnode_pager_input_old(object, m[reqpage]);
for (i = 0; i < count; i++) {
PCPU_INC(cnt.v_vnodein);
PCPU_INC(cnt.v_vnodepgsin);
error = vnode_pager_input_old(object, m[i]);
if (error)
break;
}
VM_OBJECT_WUNLOCK(object);
return (error);
} else if (error != 0) {
relpbuf(bp, freecnt);
vm_pager_free_nonreq(object, m, reqpage, count, FALSE);
return (VM_PAGER_ERROR);
/*
* If the blocksize is smaller than a page size, then use
* special small filesystem code.
*/
} else if ((PAGE_SIZE / bsize) > 1) {
relpbuf(bp, freecnt);
vm_pager_free_nonreq(object, m, reqpage, count, FALSE);
PCPU_INC(cnt.v_vnodein);
PCPU_INC(cnt.v_vnodepgsin);
return (vnode_pager_input_smlfs(object, m[reqpage]));
}
/*
* Since the caller has busied the requested page, that page's valid
* field will not be changed by other threads.
* If the file system supports BMAP, but blocksize is smaller
* than a page size, then use special small filesystem code.
*/
vm_page_assert_xbusied(m[reqpage]);
if (pagesperblock == 0) {
for (i = 0; i < count; i++) {
PCPU_INC(cnt.v_vnodein);
PCPU_INC(cnt.v_vnodepgsin);
error = vnode_pager_input_smlfs(object, m[i]);
if (error)
break;
}
return (error);
}
/*
* If we have a completely valid page available to us, we can
* clean up and return. Otherwise we have to re-read the
* media.
* A sparse file can be encountered only for a single page request,
* which may not be preceeded by call to vm_pager_haspage().
*/
if (m[reqpage]->valid == VM_PAGE_BITS_ALL) {
if (bp->b_blkno == -1) {
KASSERT(count == 1,
("%s: array[%d] request to a sparse file %p", __func__,
count, vp));
relpbuf(bp, freecnt);
vm_pager_free_nonreq(object, m, reqpage, count, FALSE);
return (VM_PAGER_OK);
} else if (reqblock == -1) {
relpbuf(bp, freecnt);
pmap_zero_page(m[reqpage]);
KASSERT(m[reqpage]->dirty == 0,
("vnode_pager_generic_getpages: page %p is dirty", m));
pmap_zero_page(m[0]);
KASSERT(m[0]->dirty == 0, ("%s: page %p is dirty",
__func__, m[0]));
VM_OBJECT_WLOCK(object);
m[reqpage]->valid = VM_PAGE_BITS_ALL;
vm_pager_free_nonreq(object, m, reqpage, count, TRUE);
m[0]->valid = VM_PAGE_BITS_ALL;
VM_OBJECT_WUNLOCK(object);
return (VM_PAGER_OK);
} else if (m[reqpage]->valid != 0) {
VM_OBJECT_WLOCK(object);
m[reqpage]->valid = 0;
VM_OBJECT_WUNLOCK(object);
}
pib = IDX_TO_OFF(m[reqpage]->pindex) % bsize;
pbefore = ((daddr_t)before * bsize + pib) / PAGE_SIZE;
pafter = ((daddr_t)(after + 1) * bsize - pib) / PAGE_SIZE - 1;
first = reqpage < pbefore ? 0 : reqpage - pbefore;
last = reqpage + pafter >= count ? count - 1 : reqpage + pafter;
if (first > 0 || last + 1 < count) {
bp->b_blkno += (foff % bsize) / DEV_BSIZE;
/* Recalculate blocks available after/before to pages. */
poff = (foff % bsize) / PAGE_SIZE;
before *= pagesperblock;
before += poff;
after *= pagesperblock;
after += pagesperblock - (poff + 1);
if (m[0]->pindex + after >= object->size)
after = object->size - 1 - m[0]->pindex;
KASSERT(count <= after + 1, ("%s: %d pages asked, can do only %d",
__func__, count, after + 1));
after -= count - 1;
/* Trim requested rbehind/rahead to possible values. */
rbehind = a_rbehind ? *a_rbehind : 0;
rahead = a_rahead ? *a_rahead : 0;
rbehind = min(rbehind, before);
rbehind = min(rbehind, m[0]->pindex);
rahead = min(rahead, after);
rahead = min(rahead, object->size - m[count - 1]->pindex);
KASSERT(rbehind + rahead + count <= sizeof(bp->b_pages),
("%s: behind %d ahead %d count %d", __func__,
rbehind, rahead, count));
/*
* Fill in the bp->b_pages[] array with requested and optional
* read behind or read ahead pages. Read behind pages are looked
* up in a backward direction, down to a first cached page. Same
* for read ahead pages, but there is no need to shift the array
* in case of encountering a cached page.
*/
i = bp->b_npages = 0;
if (rbehind) {
vm_pindex_t startpindex, tpindex;
vm_page_t p;
VM_OBJECT_WLOCK(object);
for (i = 0; i < first; i++) {
vm_page_lock(m[i]);
vm_page_free(m[i]);
vm_page_unlock(m[i]);
startpindex = m[0]->pindex - rbehind;
if ((p = TAILQ_PREV(m[0], pglist, listq)) != NULL &&
p->pindex >= startpindex)
startpindex = p->pindex + 1;
/* tpindex is unsigned; beware of numeric underflow. */
for (tpindex = m[0]->pindex - 1;
tpindex >= startpindex && tpindex < m[0]->pindex;
tpindex--, i++) {
p = vm_page_alloc(object, tpindex, VM_ALLOC_NORMAL |
VM_ALLOC_IFNOTCACHED);
if (p == NULL) {
/* Shift the array. */
for (int j = 0; j < i; j++)
bp->b_pages[j] = bp->b_pages[j +
tpindex + 1 - startpindex];
break;
}
bp->b_pages[tpindex - startpindex] = p;
}
for (i = last + 1; i < count; i++) {
vm_page_lock(m[i]);
vm_page_free(m[i]);
vm_page_unlock(m[i]);
bp->b_pgbefore = i;
bp->b_npages += i;
bp->b_blkno -= IDX_TO_OFF(i) / DEV_BSIZE;
} else
bp->b_pgbefore = 0;
/* Requested pages. */
for (int j = 0; j < count; j++, i++)
bp->b_pages[i] = m[j];
bp->b_npages += count;
if (rahead) {
vm_pindex_t endpindex, tpindex;
vm_page_t p;
if (!VM_OBJECT_WOWNED(object))
VM_OBJECT_WLOCK(object);
endpindex = m[count - 1]->pindex + rahead + 1;
if ((p = TAILQ_NEXT(m[count - 1], listq)) != NULL &&
p->pindex < endpindex)
endpindex = p->pindex;
if (endpindex > object->size)
endpindex = object->size;
for (tpindex = m[count - 1]->pindex + 1;
tpindex < endpindex; i++, tpindex++) {
p = vm_page_alloc(object, tpindex, VM_ALLOC_NORMAL |
VM_ALLOC_IFNOTCACHED);
if (p == NULL)
break;
bp->b_pages[i] = p;
}
bp->b_pgafter = i - bp->b_npages;
bp->b_npages = i;
} else
bp->b_pgafter = 0;
if (VM_OBJECT_WOWNED(object))
VM_OBJECT_WUNLOCK(object);
}
/* Report back actual behind/ahead read. */
if (a_rbehind)
*a_rbehind = bp->b_pgbefore;
if (a_rahead)
*a_rahead = bp->b_pgafter;
KASSERT(bp->b_npages <= sizeof(bp->b_pages),
("%s: buf %p overflowed", __func__, bp));
/*
* here on direct device I/O
*/
firstaddr = reqblock;
firstaddr += pib / DEV_BSIZE;
firstaddr -= IDX_TO_OFF(reqpage - first) / DEV_BSIZE;
/*
* The first and last page have been calculated now, move
* input pages to be zero based, and adjust the count.
*/
m += first;
reqpage -= first;
count = last - first + 1;
/*
* calculate the file virtual address for the transfer
*/
foff = IDX_TO_OFF(m[0]->pindex);
/*
* calculate the size of the transfer
*/
size = count * PAGE_SIZE;
KASSERT(count > 0, ("zero count"));
if ((foff + size) > object->un_pager.vnp.vnp_size)
size = object->un_pager.vnp.vnp_size - foff;
KASSERT(size > 0, ("zero size"));
/*
* round up physical size for real devices.
* Recalculate first offset and bytecount with regards to read behind.
* Truncate bytecount to vnode real size and round up physical size
* for real devices.
*/
foff = IDX_TO_OFF(bp->b_pages[0]->pindex);
bytecount = bp->b_npages << PAGE_SHIFT;
if ((foff + bytecount) > object->un_pager.vnp.vnp_size)
bytecount = object->un_pager.vnp.vnp_size - foff;
secmask = bo->bo_bsize - 1;
KASSERT(secmask < PAGE_SIZE && secmask > 0,
("vnode_pager_generic_getpages: sector size %d too large",
secmask + 1));
size = (size + secmask) & ~secmask;
("%s: sector size %d too large", __func__, secmask + 1));
bytecount = (bytecount + secmask) & ~secmask;
/*
* and map the pages to be read into the kva, if the filesystem
* And map the pages to be read into the kva, if the filesystem
* requires mapped buffers.
*/
if ((vp->v_mount->mnt_kern_flag & MNTK_UNMAPPED_BUFS) != 0 &&
@ -932,41 +967,32 @@ vnode_pager_generic_getpages(struct vnode *vp, vm_page_t *m, int bytecount,
bp->b_offset = 0;
} else {
bp->b_data = bp->b_kvabase;
pmap_qenter((vm_offset_t)bp->b_data, m, count);
pmap_qenter((vm_offset_t)bp->b_data, bp->b_pages, bp->b_npages);
}
/* build a minimal buffer header */
/* Build a minimal buffer header. */
bp->b_iocmd = BIO_READ;
KASSERT(bp->b_rcred == NOCRED, ("leaking read ucred"));
KASSERT(bp->b_wcred == NOCRED, ("leaking write ucred"));
bp->b_rcred = crhold(curthread->td_ucred);
bp->b_wcred = crhold(curthread->td_ucred);
bp->b_blkno = firstaddr;
pbgetbo(bo, bp);
bp->b_vp = vp;
bp->b_bcount = size;
bp->b_bufsize = size;
bp->b_runningbufspace = bp->b_bufsize;
for (i = 0; i < count; i++)
bp->b_pages[i] = m[i];
bp->b_npages = count;
bp->b_pager.pg_reqpage = reqpage;
atomic_add_long(&runningbufspace, bp->b_runningbufspace);
PCPU_INC(cnt.v_vnodein);
PCPU_ADD(cnt.v_vnodepgsin, count);
/* do the input */
bp->b_bcount = bp->b_bufsize = bp->b_runningbufspace = bytecount;
bp->b_iooffset = dbtob(bp->b_blkno);
atomic_add_long(&runningbufspace, bp->b_runningbufspace);
PCPU_INC(cnt.v_vnodein);
PCPU_ADD(cnt.v_vnodepgsin, bp->b_npages);
if (iodone != NULL) { /* async */
bp->b_pager.pg_iodone = iodone;
bp->b_pgiodone = iodone;
bp->b_caller1 = arg;
bp->b_iodone = vnode_pager_generic_getpages_done_async;
bp->b_flags |= B_ASYNC;
BUF_KERNPROC(bp);
bstrategy(bp);
/* Good bye! */
return (VM_PAGER_OK);
} else {
bp->b_iodone = bdone;
bstrategy(bp);
@ -977,9 +1003,8 @@ vnode_pager_generic_getpages(struct vnode *vp, vm_page_t *m, int bytecount,
bp->b_vp = NULL;
pbrelbo(bp);
relpbuf(bp, &vnode_pbuf_freecnt);
return (error != 0 ? VM_PAGER_ERROR : VM_PAGER_OK);
}
return (error != 0 ? VM_PAGER_ERROR : VM_PAGER_OK);
}
static void
@ -988,8 +1013,9 @@ vnode_pager_generic_getpages_done_async(struct buf *bp)
int error;
error = vnode_pager_generic_getpages_done(bp);
bp->b_pager.pg_iodone(bp->b_caller1, bp->b_pages,
bp->b_pager.pg_reqpage, error);
/* Run the iodone upon the requested range. */
bp->b_pgiodone(bp->b_caller1, bp->b_pages + bp->b_pgbefore,
bp->b_npages - bp->b_pgbefore - bp->b_pgafter, error);
for (int i = 0; i < bp->b_npages; i++)
bp->b_pages[i] = NULL;
bp->b_vp = NULL;
@ -1052,8 +1078,8 @@ vnode_pager_generic_getpages_done(struct buf *bp)
object->un_pager.vnp.vnp_size - tfoff)) == 0,
("%s: page %p is dirty", __func__, mt));
}
if (i != bp->b_pager.pg_reqpage)
if (i < bp->b_pgbefore || i >= bp->b_npages - bp->b_pgafter)
vm_page_readahead_finish(mt);
}
VM_OBJECT_WUNLOCK(object);

3
sys/vm/vnode_pager.h
View File

@ -41,7 +41,8 @@
#ifdef _KERNEL
int vnode_pager_generic_getpages(struct vnode *vp, vm_page_t *m,
int count, int reqpage, vop_getpages_iodone_t iodone, void *arg);
int count, int *rbehind, int *rahead, vop_getpages_iodone_t iodone,
void *arg);
int vnode_pager_generic_putpages(struct vnode *vp, vm_page_t *m,
int count, boolean_t sync,
int *rtvals);