Author: jhb
Date: Thu Jan 5 18:50:37 2012
New Revision: 229618
URL: http://svn.freebsd.org/changeset/base/229618
Log:
MFC 228185:
Enhance the sequential access heuristic used to perform readahead in the
NFS server and reuse it for writes as well to allow writes to the backing
store to be clustered.
Modified:
stable/8/sys/fs/nfsserver/nfs_nfsdport.c
stable/8/sys/nfsserver/nfs_serv.c
Directory Properties:
stable/8/sys/ (props changed)
stable/8/sys/amd64/include/xen/ (props changed)
stable/8/sys/cddl/contrib/opensolaris/ (props changed)
stable/8/sys/contrib/dev/acpica/ (props changed)
stable/8/sys/contrib/pf/ (props changed)
Modified: stable/8/sys/fs/nfsserver/nfs_nfsdport.c
==============================================================================
--- stable/8/sys/fs/nfsserver/nfs_nfsdport.c Thu Jan 5 18:50:12 2012
(r229617)
+++ stable/8/sys/fs/nfsserver/nfs_nfsdport.c Thu Jan 5 18:50:37 2012
(r229618)
@@ -86,20 +86,78 @@ SYSCTL_INT(_vfs_newnfs, OID_AUTO, issue_
SYSCTL_INT(_vfs_newnfs, OID_AUTO, enable_locallocks, CTLFLAG_RW,
&nfsrv_dolocallocks, 0, "Enable nfsd to acquire local locks on files");
-#define NUM_HEURISTIC 1017
+#define MAX_REORDERED_RPC 16
+#define NUM_HEURISTIC 1031
#define NHUSE_INIT 64
#define NHUSE_INC 16
#define NHUSE_MAX 2048
static struct nfsheur {
struct vnode *nh_vp; /* vp to match (unreferenced pointer) */
- off_t nh_nextr; /* next offset for sequential detection */
+ off_t nh_nextoff; /* next offset for sequential detection */
int nh_use; /* use count for selection */
int nh_seqcount; /* heuristic */
} nfsheur[NUM_HEURISTIC];
/*
+ * Heuristic to detect sequential operation.
+ */
+static struct nfsheur *
+nfsrv_sequential_heuristic(struct uio *uio, struct vnode *vp)
+{
+ struct nfsheur *nh;
+ int hi, try;
+
+ /* Locate best candidate. */
+ try = 32;
+ hi = ((int)(vm_offset_t)vp / sizeof(struct vnode)) % NUM_HEURISTIC;
+ nh = &nfsheur[hi];
+ while (try--) {
+ if (nfsheur[hi].nh_vp == vp) {
+ nh = &nfsheur[hi];
+ break;
+ }
+ if (nfsheur[hi].nh_use > 0)
+ --nfsheur[hi].nh_use;
+ hi = (hi + 1) % NUM_HEURISTIC;
+ if (nfsheur[hi].nh_use < nh->nh_use)
+ nh = &nfsheur[hi];
+ }
+
+ /* Initialize hint if this is a new file. */
+ if (nh->nh_vp != vp) {
+ nh->nh_vp = vp;
+ nh->nh_nextoff = uio->uio_offset;
+ nh->nh_use = NHUSE_INIT;
+ if (uio->uio_offset == 0)
+ nh->nh_seqcount = 4;
+ else
+ nh->nh_seqcount = 1;
+ }
+
+ /* Calculate heuristic. */
+ if ((uio->uio_offset == 0 && nh->nh_seqcount > 0) ||
+ uio->uio_offset == nh->nh_nextoff) {
+ /* See comments in vfs_vnops.c:sequential_heuristic(). */
+ nh->nh_seqcount += howmany(uio->uio_resid, 16384);
+ if (nh->nh_seqcount > IO_SEQMAX)
+ nh->nh_seqcount = IO_SEQMAX;
+ } else if (qabs(uio->uio_offset - nh->nh_nextoff) <= MAX_REORDERED_RPC *
+ imax(vp->v_mount->mnt_stat.f_iosize, uio->uio_resid)) {
+ /* Probably a reordered RPC, leave seqcount alone. */
+ } else if (nh->nh_seqcount > 1) {
+ nh->nh_seqcount /= 2;
+ } else {
+ nh->nh_seqcount = 0;
+ }
+ nh->nh_use += NHUSE_INC;
+ if (nh->nh_use > NHUSE_MAX)
+ nh->nh_use = NHUSE_MAX;
+ return (nh);
+}
+
+/*
* Get attributes into nfsvattr structure.
*/
int
@@ -562,60 +620,11 @@ nfsvno_read(struct vnode *vp, off_t off,
int i;
struct iovec *iv;
struct iovec *iv2;
- int error = 0, len, left, siz, tlen, ioflag = 0, hi, try = 32;
+ int error = 0, len, left, siz, tlen, ioflag = 0;
struct mbuf *m2 = NULL, *m3;
struct uio io, *uiop = &io;
struct nfsheur *nh;
- /*
- * Calculate seqcount for heuristic
- */
- /*
- * Locate best candidate
- */
-
- hi = ((int)(vm_offset_t)vp / sizeof(struct vnode)) % NUM_HEURISTIC;
- nh = &nfsheur[hi];
-
- while (try--) {
- if (nfsheur[hi].nh_vp == vp) {
- nh = &nfsheur[hi];
- break;
- }
- if (nfsheur[hi].nh_use > 0)
- --nfsheur[hi].nh_use;
- hi = (hi + 1) % NUM_HEURISTIC;
- if (nfsheur[hi].nh_use < nh->nh_use)
- nh = &nfsheur[hi];
- }
-
- if (nh->nh_vp != vp) {
- nh->nh_vp = vp;
- nh->nh_nextr = off;
- nh->nh_use = NHUSE_INIT;
- if (off == 0)
- nh->nh_seqcount = 4;
- else
- nh->nh_seqcount = 1;
- }
-
- /*
- * Calculate heuristic
- */
-
- if ((off == 0 && nh->nh_seqcount > 0) || off == nh->nh_nextr) {
- if (++nh->nh_seqcount > IO_SEQMAX)
- nh->nh_seqcount = IO_SEQMAX;
- } else if (nh->nh_seqcount > 1) {
- nh->nh_seqcount = 1;
- } else {
- nh->nh_seqcount = 0;
- }
- nh->nh_use += NHUSE_INC;
- if (nh->nh_use > NHUSE_MAX)
- nh->nh_use = NHUSE_MAX;
- ioflag |= nh->nh_seqcount << IO_SEQSHIFT;
-
len = left = NFSM_RNDUP(cnt);
m3 = NULL;
/*
@@ -660,6 +669,8 @@ nfsvno_read(struct vnode *vp, off_t off,
uiop->uio_resid = len;
uiop->uio_rw = UIO_READ;
uiop->uio_segflg = UIO_SYSSPACE;
+ nh = nfsrv_sequential_heuristic(uiop, vp);
+ ioflag |= nh->nh_seqcount << IO_SEQSHIFT;
error = VOP_READ(vp, uiop, IO_NODELOCKED | ioflag, cred);
FREE((caddr_t)iv2, M_TEMP);
if (error) {
@@ -667,6 +678,7 @@ nfsvno_read(struct vnode *vp, off_t off,
*mpp = NULL;
goto out;
}
+ nh->nh_nextoff = uiop->uio_offset;
tlen = len - uiop->uio_resid;
cnt = cnt < tlen ? cnt : tlen;
tlen = NFSM_RNDUP(cnt);
@@ -695,6 +707,7 @@ nfsvno_write(struct vnode *vp, off_t off
struct iovec *iv;
int ioflags, error;
struct uio io, *uiop = &io;
+ struct nfsheur *nh;
MALLOC(ivp, struct iovec *, cnt * sizeof (struct iovec), M_TEMP,
M_WAITOK);
@@ -728,7 +741,11 @@ nfsvno_write(struct vnode *vp, off_t off
uiop->uio_segflg = UIO_SYSSPACE;
NFSUIOPROC(uiop, p);
uiop->uio_offset = off;
+ nh = nfsrv_sequential_heuristic(uiop, vp);
+ ioflags |= nh->nh_seqcount << IO_SEQSHIFT;
error = VOP_WRITE(vp, uiop, ioflags, cred);
+ if (error == 0)
+ nh->nh_nextoff = uiop->uio_offset;
FREE((caddr_t)iv, M_TEMP);
NFSEXITCODE(error);
Modified: stable/8/sys/nfsserver/nfs_serv.c
==============================================================================
--- stable/8/sys/nfsserver/nfs_serv.c Thu Jan 5 18:50:12 2012
(r229617)
+++ stable/8/sys/nfsserver/nfs_serv.c Thu Jan 5 18:50:37 2012
(r229618)
@@ -105,14 +105,15 @@ __FBSDID("$FreeBSD$");
#define MAX_COMMIT_COUNT (1024 * 1024)
-#define NUM_HEURISTIC 1017
+#define MAX_REORDERED_RPC 16
+#define NUM_HEURISTIC 1031
#define NHUSE_INIT 64
#define NHUSE_INC 16
#define NHUSE_MAX 2048
static struct nfsheur {
struct vnode *nh_vp; /* vp to match (unreferenced pointer) */
- off_t nh_nextr; /* next offset for sequential detection */
+ off_t nh_nextoff; /* next offset for sequential detection */
int nh_use; /* use count for selection */
int nh_seqcount; /* heuristic */
} nfsheur[NUM_HEURISTIC];
@@ -184,6 +185,63 @@ nfsrv_lockedpair_nd(int vfs1, struct nam
}
/*
+ * Heuristic to detect sequential operation.
+ */
+static struct nfsheur *
+nfsrv_sequential_heuristic(struct uio *uio, struct vnode *vp)
+{
+ struct nfsheur *nh;
+ int hi, try;
+
+ /* Locate best candidate. */
+ try = 32;
+ hi = ((int)(vm_offset_t)vp / sizeof(struct vnode)) % NUM_HEURISTIC;
+ nh = &nfsheur[hi];
+ while (try--) {
+ if (nfsheur[hi].nh_vp == vp) {
+ nh = &nfsheur[hi];
+ break;
+ }
+ if (nfsheur[hi].nh_use > 0)
+ --nfsheur[hi].nh_use;
+ hi = (hi + 1) % NUM_HEURISTIC;
+ if (nfsheur[hi].nh_use < nh->nh_use)
+ nh = &nfsheur[hi];
+ }
+
+ /* Initialize hint if this is a new file. */
+ if (nh->nh_vp != vp) {
+ nh->nh_vp = vp;
+ nh->nh_nextoff = uio->uio_offset;
+ nh->nh_use = NHUSE_INIT;
+ if (uio->uio_offset == 0)
+ nh->nh_seqcount = 4;
+ else
+ nh->nh_seqcount = 1;
+ }
+
+ /* Calculate heuristic. */
+ if ((uio->uio_offset == 0 && nh->nh_seqcount > 0) ||
+ uio->uio_offset == nh->nh_nextoff) {
+ /* See comments in vfs_vnops.c:sequential_heuristic(). */
+ nh->nh_seqcount += howmany(uio->uio_resid, 16384);
+ if (nh->nh_seqcount > IO_SEQMAX)
+ nh->nh_seqcount = IO_SEQMAX;
+ } else if (qabs(uio->uio_offset - nh->nh_nextoff) <= MAX_REORDERED_RPC *
+ imax(vp->v_mount->mnt_stat.f_iosize, uio->uio_resid)) {
+ /* Probably a reordered RPC, leave seqcount alone. */
+ } else if (nh->nh_seqcount > 1) {
+ nh->nh_seqcount /= 2;
+ } else {
+ nh->nh_seqcount = 0;
+ }
+ nh->nh_use += NHUSE_INC;
+ if (nh->nh_use > NHUSE_MAX)
+ nh->nh_use = NHUSE_MAX;
+ return (nh);
+}
+
+/*
* nfs v3 access service
*/
int
@@ -840,7 +898,6 @@ nfsrv_read(struct nfsrv_descript *nfsd,
/*
* Calculate byte count to read
*/
-
if (off >= vap->va_size)
cnt = 0;
else if ((off + reqlen) > vap->va_size)
@@ -848,61 +905,6 @@ nfsrv_read(struct nfsrv_descript *nfsd,
else
cnt = reqlen;
- /*
- * Calculate seqcount for heuristic
- */
-
- {
- int hi;
- int try = 32;
-
- /*
- * Locate best candidate
- */
-
- hi = ((int)(vm_offset_t)vp / sizeof(struct vnode)) %
NUM_HEURISTIC;
- nh = &nfsheur[hi];
-
- while (try--) {
- if (nfsheur[hi].nh_vp == vp) {
- nh = &nfsheur[hi];
- break;
- }
- if (nfsheur[hi].nh_use > 0)
- --nfsheur[hi].nh_use;
- hi = (hi + 1) % NUM_HEURISTIC;
- if (nfsheur[hi].nh_use < nh->nh_use)
- nh = &nfsheur[hi];
- }
-
- if (nh->nh_vp != vp) {
- nh->nh_vp = vp;
- nh->nh_nextr = off;
- nh->nh_use = NHUSE_INIT;
- if (off == 0)
- nh->nh_seqcount = 4;
- else
- nh->nh_seqcount = 1;
- }
-
- /*
- * Calculate heuristic
- */
-
- if ((off == 0 && nh->nh_seqcount > 0) || off == nh->nh_nextr) {
- if (++nh->nh_seqcount > IO_SEQMAX)
- nh->nh_seqcount = IO_SEQMAX;
- } else if (nh->nh_seqcount > 1) {
- nh->nh_seqcount = 1;
- } else {
- nh->nh_seqcount = 0;
- }
- nh->nh_use += NHUSE_INC;
- if (nh->nh_use > NHUSE_MAX)
- nh->nh_use = NHUSE_MAX;
- ioflag |= nh->nh_seqcount << IO_SEQSHIFT;
- }
-
nfsm_reply(NFSX_POSTOPORFATTR(v3) + 3 * NFSX_UNSIGNED+nfsm_rndup(cnt));
if (v3) {
tl = nfsm_build(u_int32_t *, NFSX_V3FATTR + 4 * NFSX_UNSIGNED);
@@ -960,9 +962,11 @@ nfsrv_read(struct nfsrv_descript *nfsd,
uiop->uio_resid = len;
uiop->uio_rw = UIO_READ;
uiop->uio_segflg = UIO_SYSSPACE;
+ nh = nfsrv_sequential_heuristic(uiop, vp);
+ ioflag |= nh->nh_seqcount << IO_SEQSHIFT;
error = VOP_READ(vp, uiop, IO_NODELOCKED | ioflag, cred);
- off = uiop->uio_offset;
- nh->nh_nextr = off;
+ if (error == 0)
+ nh->nh_nextoff = uiop->uio_offset;
free((caddr_t)iv2, M_TEMP);
if (error || (getret = VOP_GETATTR(vp, vap, cred))) {
if (!error)
@@ -1027,6 +1031,7 @@ nfsrv_write(struct nfsrv_descript *nfsd,
int v3 = (nfsd->nd_flag & ND_NFSV3);
struct mbuf *mb, *mreq;
struct vnode *vp = NULL;
+ struct nfsheur *nh;
nfsfh_t nfh;
fhandle_t *fhp;
struct uio io, *uiop = &io;
@@ -1167,7 +1172,11 @@ nfsrv_write(struct nfsrv_descript *nfsd,
uiop->uio_segflg = UIO_SYSSPACE;
uiop->uio_td = NULL;
uiop->uio_offset = off;
+ nh = nfsrv_sequential_heuristic(uiop, vp);
+ ioflags |= nh->nh_seqcount << IO_SEQSHIFT;
error = VOP_WRITE(vp, uiop, ioflags, cred);
+ if (error == 0)
+ nh->nh_nextoff = uiop->uio_offset;
/* Unlocked write. */
nfsrvstats.srvvop_writes++;
free((caddr_t)iv, M_TEMP);
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