Module Name: src
Committed By: ad
Date: Fri Jan 24 16:05:23 UTC 2020
Modified Files:
src/sys/kern [ad-namecache]: vfs_subr.c vfs_vnode.c
src/sys/miscfs/genfs [ad-namecache]: genfs_vnops.c
src/sys/sys [ad-namecache]: vnode.h vnode_impl.h
Log Message:
vnodes:
- Have own v_usecount again, don't share the uvm_object's refcount.
- Cluster the members of vnode_t and vnode_impl_t in a cache-concious way.
- Go back to having vi_lock directly in vnode_impl_t.
- Go back to having v_usecount adjusted with atomics.
- Start adjusting v_holdcnt with atomics, too.
- Put all the namecache stuff back into vnode_impl_t.
To generate a diff of this commit:
cvs rdiff -u -r1.478.2.1 -r1.478.2.2 src/sys/kern/vfs_subr.c
cvs rdiff -u -r1.105.2.4 -r1.105.2.5 src/sys/kern/vfs_vnode.c
cvs rdiff -u -r1.200.2.2 -r1.200.2.3 src/sys/miscfs/genfs/genfs_vnops.c
cvs rdiff -u -r1.286 -r1.286.2.1 src/sys/sys/vnode.h
cvs rdiff -u -r1.19.2.4 -r1.19.2.5 src/sys/sys/vnode_impl.h
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/kern/vfs_subr.c
diff -u src/sys/kern/vfs_subr.c:1.478.2.1 src/sys/kern/vfs_subr.c:1.478.2.2
--- src/sys/kern/vfs_subr.c:1.478.2.1 Fri Jan 17 21:47:35 2020
+++ src/sys/kern/vfs_subr.c Fri Jan 24 16:05:22 2020
@@ -1,4 +1,4 @@
-/* $NetBSD: vfs_subr.c,v 1.478.2.1 2020/01/17 21:47:35 ad Exp $ */
+/* $NetBSD: vfs_subr.c,v 1.478.2.2 2020/01/24 16:05:22 ad Exp $ */
/*-
* Copyright (c) 1997, 1998, 2004, 2005, 2007, 2008, 2019
@@ -69,7 +69,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: vfs_subr.c,v 1.478.2.1 2020/01/17 21:47:35 ad Exp $");
+__KERNEL_RCSID(0, "$NetBSD: vfs_subr.c,v 1.478.2.2 2020/01/24 16:05:22 ad Exp $");
#ifdef _KERNEL_OPT
#include "opt_ddb.h"
@@ -1111,7 +1111,7 @@ vprint_common(struct vnode *vp, const ch
vp->v_usecount, vp->v_writecount, vp->v_holdcnt);
(*pr)("%ssize %" PRIx64 " writesize %" PRIx64 " numoutput %d\n",
prefix, vp->v_size, vp->v_writesize, vp->v_numoutput);
- (*pr)("%sdata %p lock %p\n", prefix, vp->v_data, vip->vi_lock);
+ (*pr)("%sdata %p lock %p\n", prefix, vp->v_data, &vip->vi_lock);
(*pr)("%sstate %s key(%p %zd)", prefix, vstate_name(vip->vi_state),
vip->vi_key.vk_mount, vip->vi_key.vk_key_len);
@@ -1544,7 +1544,7 @@ vfs_vnode_lock_print(void *vlock, int fu
for (mp = _mountlist_next(NULL); mp; mp = _mountlist_next(mp)) {
TAILQ_FOREACH(vip, &mp->mnt_vnodelist, vi_mntvnodes) {
- if (vip->vi_lock == vlock ||
+ if (&vip->vi_lock == vlock ||
VIMPL_TO_VNODE(vip)->v_interlock == vlock)
vfs_vnode_print(VIMPL_TO_VNODE(vip), full, pr);
}
Index: src/sys/kern/vfs_vnode.c
diff -u src/sys/kern/vfs_vnode.c:1.105.2.4 src/sys/kern/vfs_vnode.c:1.105.2.5
--- src/sys/kern/vfs_vnode.c:1.105.2.4 Thu Jan 23 19:28:39 2020
+++ src/sys/kern/vfs_vnode.c Fri Jan 24 16:05:22 2020
@@ -1,4 +1,4 @@
-/* $NetBSD: vfs_vnode.c,v 1.105.2.4 2020/01/23 19:28:39 ad Exp $ */
+/* $NetBSD: vfs_vnode.c,v 1.105.2.5 2020/01/24 16:05:22 ad Exp $ */
/*-
* Copyright (c) 1997-2011, 2019 The NetBSD Foundation, Inc.
@@ -142,10 +142,19 @@
* as vput(9), routines. Common points holding references are e.g.
* file openings, current working directory, mount points, etc.
*
+ * Note on v_usecount & v_holdcnt and their locking
+ *
+ * At nearly all points it is known that the counts could be zero,
+ * the vnode_t::v_interlock will be held. To change the counts away
+ * from zero, the interlock must be held. To change from a non-zero
+ * value to zero, again the interlock must be held.
+ *
+ * Changing the usecount from a non-zero value to a non-zero value can
+ * safely be done using atomic operations, without the interlock held.
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: vfs_vnode.c,v 1.105.2.4 2020/01/23 19:28:39 ad Exp $");
+__KERNEL_RCSID(0, "$NetBSD: vfs_vnode.c,v 1.105.2.5 2020/01/24 16:05:22 ad Exp $");
#include <sys/param.h>
#include <sys/kernel.h>
@@ -669,6 +678,27 @@ vdrain_thread(void *cookie)
}
/*
+ * Try to drop reference on a vnode. Abort if we are releasing the
+ * last reference. Note: this _must_ succeed if not the last reference.
+ */
+static bool
+vtryrele(vnode_t *vp)
+{
+ u_int use, next;
+
+ for (use = vp->v_usecount;; use = next) {
+ if (__predict_false(use == 1)) {
+ return false;
+ }
+ KASSERT(use > 1);
+ next = atomic_cas_uint(&vp->v_usecount, use, use - 1);
+ if (__predict_true(next == use)) {
+ return true;
+ }
+ }
+}
+
+/*
* vput: unlock and release the reference.
*/
void
@@ -676,7 +706,20 @@ vput(vnode_t *vp)
{
int lktype;
- if ((vp->v_vflag & VV_LOCKSWORK) == 0) {
+ /*
+ * Do an unlocked check of v_usecount. If it looks like we're not
+ * about to drop the last reference, then unlock the vnode and try
+ * to drop the reference. If it ends up being the last reference
+ * after all, we dropped the lock when we shouldn't have. vrelel()
+ * can fix it all up. Most of the time this will all go to plan.
+ */
+ if (vp->v_usecount > 1) {
+ VOP_UNLOCK(vp);
+ if (vtryrele(vp)) {
+ return;
+ }
+ lktype = LK_NONE;
+ } else if ((vp->v_vflag & VV_LOCKSWORK) == 0) {
lktype = LK_EXCLUSIVE;
} else {
lktype = VOP_ISLOCKED(vp);
@@ -708,11 +751,10 @@ vrelel(vnode_t *vp, int flags, int lktyp
* If not the last reference, just drop the reference count
* and unlock.
*/
- if (vp->v_usecount > 1) {
+ if (vtryrele(vp)) {
if (lktype != LK_NONE) {
VOP_UNLOCK(vp);
}
- vp->v_usecount--;
mutex_exit(vp->v_interlock);
return;
}
@@ -792,8 +834,7 @@ vrelel(vnode_t *vp, int flags, int lktyp
mutex_enter(vp->v_interlock);
if (!recycle) {
VOP_UNLOCK(vp);
- if (vp->v_usecount > 1) {
- vp->v_usecount--;
+ if (vtryrele(vp)) {
mutex_exit(vp->v_interlock);
return;
}
@@ -820,8 +861,7 @@ vrelel(vnode_t *vp, int flags, int lktyp
KASSERT(vp->v_usecount > 0);
}
- vp->v_usecount--;
- if (vp->v_usecount != 0) {
+ if (atomic_dec_uint_nv(&vp->v_usecount) != 0) {
/* Gained another reference while being reclaimed. */
mutex_exit(vp->v_interlock);
return;
@@ -848,6 +888,9 @@ void
vrele(vnode_t *vp)
{
+ if (vtryrele(vp)) {
+ return;
+ }
mutex_enter(vp->v_interlock);
vrelel(vp, 0, LK_NONE);
}
@@ -859,6 +902,9 @@ void
vrele_async(vnode_t *vp)
{
+ if (vtryrele(vp)) {
+ return;
+ }
mutex_enter(vp->v_interlock);
vrelel(vp, VRELEL_ASYNC, LK_NONE);
}
@@ -873,9 +919,7 @@ vref(vnode_t *vp)
KASSERT(vp->v_usecount != 0);
- mutex_enter(vp->v_interlock);
- vp->v_usecount++;
- mutex_exit(vp->v_interlock);
+ atomic_inc_uint(&vp->v_usecount);
}
/*
@@ -888,11 +932,34 @@ vholdl(vnode_t *vp)
KASSERT(mutex_owned(vp->v_interlock));
- if (vp->v_holdcnt++ == 0 && vp->v_usecount == 0)
+ if (atomic_inc_uint_nv(&vp->v_holdcnt) == 1 && vp->v_usecount == 0)
lru_requeue(vp, lru_which(vp));
}
/*
+ * Page or buffer structure gets a reference.
+ */
+void
+vhold(vnode_t *vp)
+{
+ int hold, next;
+
+ for (hold = vp->v_holdcnt;; hold = next) {
+ if (__predict_false(hold == 0)) {
+ break;
+ }
+ next = atomic_cas_uint(&vp->v_holdcnt, hold, hold + 1);
+ if (__predict_true(next == hold)) {
+ return;
+ }
+ }
+
+ mutex_enter(vp->v_interlock);
+ vholdl(vp);
+ mutex_exit(vp->v_interlock);
+}
+
+/*
* Page or buffer structure frees a reference.
* Called with v_interlock held.
*/
@@ -906,12 +973,35 @@ holdrelel(vnode_t *vp)
vnpanic(vp, "%s: holdcnt vp %p", __func__, vp);
}
- vp->v_holdcnt--;
- if (vp->v_holdcnt == 0 && vp->v_usecount == 0)
+ if (atomic_dec_uint_nv(&vp->v_holdcnt) == 0 && vp->v_usecount == 0)
lru_requeue(vp, lru_which(vp));
}
/*
+ * Page or buffer structure frees a reference.
+ */
+void
+holdrele(vnode_t *vp)
+{
+ int hold, next;
+
+ for (hold = vp->v_holdcnt;; hold = next) {
+ if (__predict_false(hold == 1)) {
+ break;
+ }
+ KASSERT(hold > 1);
+ next = atomic_cas_uint(&vp->v_holdcnt, hold, hold - 1);
+ if (__predict_true(next == hold)) {
+ return;
+ }
+ }
+
+ mutex_enter(vp->v_interlock);
+ holdrelel(vp);
+ mutex_exit(vp->v_interlock);
+}
+
+/*
* Recycle an unused vnode if caller holds the last reference.
*/
bool
@@ -1013,7 +1103,7 @@ vrevoke(vnode_t *vp)
if (VSTATE_GET(vp) == VS_RECLAIMED) {
mutex_exit(vp->v_interlock);
} else if (vp->v_type != VBLK && vp->v_type != VCHR) {
- vp->v_usecount++;
+ atomic_inc_uint(&vp->v_usecount);
mutex_exit(vp->v_interlock);
vgone(vp);
} else {
@@ -1068,8 +1158,8 @@ static void
vcache_init(void)
{
- vcache_pool = pool_cache_init(sizeof(vnode_impl_t), 0, 0, 0,
- "vcachepl", NULL, IPL_NONE, NULL, NULL, NULL);
+ vcache_pool = pool_cache_init(sizeof(vnode_impl_t), coherency_unit,
+ 0, 0, "vcachepl", NULL, IPL_NONE, NULL, NULL, NULL);
KASSERT(vcache_pool != NULL);
mutex_init(&vcache_lock, MUTEX_DEFAULT, IPL_NONE);
cv_init(&vcache_cv, "vcache");
@@ -1139,7 +1229,7 @@ vcache_alloc(void)
vip = pool_cache_get(vcache_pool, PR_WAITOK);
memset(vip, 0, sizeof(*vip));
- vip->vi_lock = rw_obj_alloc();
+ rw_init(&vip->vi_lock);
vp = VIMPL_TO_VNODE(vip);
uvm_obj_init(&vp->v_uobj, &uvm_vnodeops, true, 0);
@@ -1201,7 +1291,7 @@ vcache_free(vnode_impl_t *vip)
if (vp->v_type == VBLK || vp->v_type == VCHR)
spec_node_destroy(vp);
- rw_obj_free(vip->vi_lock);
+ rw_destroy(&vip->vi_lock);
uvm_obj_destroy(&vp->v_uobj, true);
cv_destroy(&vp->v_cv);
cache_vnode_fini(vp);
@@ -1226,8 +1316,10 @@ vcache_tryvget(vnode_t *vp)
error = ENOENT;
else if (__predict_false(VSTATE_GET(vp) != VS_LOADED))
error = EBUSY;
+ else if (vp->v_usecount == 0)
+ vp->v_usecount = 1;
else
- vp->v_usecount++;
+ atomic_inc_uint(&vp->v_usecount);
mutex_exit(vp->v_interlock);
@@ -1261,7 +1353,10 @@ vcache_vget(vnode_t *vp)
return ENOENT;
}
VSTATE_ASSERT(vp, VS_LOADED);
- vp->v_usecount++;
+ if (vp->v_usecount == 0)
+ vp->v_usecount = 1;
+ else
+ atomic_inc_uint(&vp->v_usecount);
mutex_exit(vp->v_interlock);
return 0;
Index: src/sys/miscfs/genfs/genfs_vnops.c
diff -u src/sys/miscfs/genfs/genfs_vnops.c:1.200.2.2 src/sys/miscfs/genfs/genfs_vnops.c:1.200.2.3
--- src/sys/miscfs/genfs/genfs_vnops.c:1.200.2.2 Wed Jan 22 12:00:18 2020
+++ src/sys/miscfs/genfs/genfs_vnops.c Fri Jan 24 16:05:22 2020
@@ -1,4 +1,4 @@
-/* $NetBSD: genfs_vnops.c,v 1.200.2.2 2020/01/22 12:00:18 ad Exp $ */
+/* $NetBSD: genfs_vnops.c,v 1.200.2.3 2020/01/24 16:05:22 ad Exp $ */
/*-
* Copyright (c) 2008 The NetBSD Foundation, Inc.
@@ -57,7 +57,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: genfs_vnops.c,v 1.200.2.2 2020/01/22 12:00:18 ad Exp $");
+__KERNEL_RCSID(0, "$NetBSD: genfs_vnops.c,v 1.200.2.3 2020/01/24 16:05:22 ad Exp $");
#include <sys/param.h>
#include <sys/systm.h>
@@ -293,19 +293,19 @@ genfs_deadlock(void *v)
return ENOENT;
if (ISSET(flags, LK_DOWNGRADE)) {
- rw_downgrade(vip->vi_lock);
+ rw_downgrade(&vip->vi_lock);
} else if (ISSET(flags, LK_UPGRADE)) {
KASSERT(ISSET(flags, LK_NOWAIT));
- if (!rw_tryupgrade(vip->vi_lock)) {
+ if (!rw_tryupgrade(&vip->vi_lock)) {
return EBUSY;
}
} else if ((flags & (LK_EXCLUSIVE | LK_SHARED)) != 0) {
op = (ISSET(flags, LK_EXCLUSIVE) ? RW_WRITER : RW_READER);
if (ISSET(flags, LK_NOWAIT)) {
- if (!rw_tryenter(vip->vi_lock, op))
+ if (!rw_tryenter(&vip->vi_lock, op))
return EBUSY;
} else {
- rw_enter(vip->vi_lock, op);
+ rw_enter(&vip->vi_lock, op);
}
}
VSTATE_ASSERT_UNLOCKED(vp, VS_RECLAIMED);
@@ -324,7 +324,7 @@ genfs_deadunlock(void *v)
vnode_t *vp = ap->a_vp;
vnode_impl_t *vip = VNODE_TO_VIMPL(vp);
- rw_exit(vip->vi_lock);
+ rw_exit(&vip->vi_lock);
return 0;
}
@@ -345,19 +345,19 @@ genfs_lock(void *v)
krw_t op;
if (ISSET(flags, LK_DOWNGRADE)) {
- rw_downgrade(vip->vi_lock);
+ rw_downgrade(&vip->vi_lock);
} else if (ISSET(flags, LK_UPGRADE)) {
KASSERT(ISSET(flags, LK_NOWAIT));
- if (!rw_tryupgrade(vip->vi_lock)) {
+ if (!rw_tryupgrade(&vip->vi_lock)) {
return EBUSY;
}
} else if ((flags & (LK_EXCLUSIVE | LK_SHARED)) != 0) {
op = (ISSET(flags, LK_EXCLUSIVE) ? RW_WRITER : RW_READER);
if (ISSET(flags, LK_NOWAIT)) {
- if (!rw_tryenter(vip->vi_lock, op))
+ if (!rw_tryenter(&vip->vi_lock, op))
return EBUSY;
} else {
- rw_enter(vip->vi_lock, op);
+ rw_enter(&vip->vi_lock, op);
}
}
VSTATE_ASSERT_UNLOCKED(vp, VS_ACTIVE);
@@ -376,7 +376,7 @@ genfs_unlock(void *v)
vnode_t *vp = ap->a_vp;
vnode_impl_t *vip = VNODE_TO_VIMPL(vp);
- rw_exit(vip->vi_lock);
+ rw_exit(&vip->vi_lock);
return 0;
}
@@ -393,10 +393,10 @@ genfs_islocked(void *v)
vnode_t *vp = ap->a_vp;
vnode_impl_t *vip = VNODE_TO_VIMPL(vp);
- if (rw_write_held(vip->vi_lock))
+ if (rw_write_held(&vip->vi_lock))
return LK_EXCLUSIVE;
- if (rw_read_held(vip->vi_lock))
+ if (rw_read_held(&vip->vi_lock))
return LK_SHARED;
return 0;
Index: src/sys/sys/vnode.h
diff -u src/sys/sys/vnode.h:1.286 src/sys/sys/vnode.h:1.286.2.1
--- src/sys/sys/vnode.h:1.286 Sun Dec 22 19:47:34 2019
+++ src/sys/sys/vnode.h Fri Jan 24 16:05:23 2020
@@ -1,4 +1,4 @@
-/* $NetBSD: vnode.h,v 1.286 2019/12/22 19:47:34 ad Exp $ */
+/* $NetBSD: vnode.h,v 1.286.2.1 2020/01/24 16:05:23 ad Exp $ */
/*-
* Copyright (c) 2008 The NetBSD Foundation, Inc.
@@ -134,20 +134,35 @@ LIST_HEAD(buflists, buf);
* it from v_data.
*/
struct vnode {
+ /*
+ * VM system related items.
+ */
struct uvm_object v_uobj; /* i: the VM object */
- kcondvar_t v_cv; /* i: synchronization */
voff_t v_size; /* i: size of file */
voff_t v_writesize; /* i: new size after write */
+
+ /*
+ * Unstable items get their own cache line.
+ * On _LP64 this fills the space nicely.
+ */
+ kcondvar_t v_cv /* i: synchronization */
+ __aligned(COHERENCY_UNIT);
int v_iflag; /* i: VI_* flags */
- int v_vflag; /* v: VV_* flags */
int v_uflag; /* u: VU_* flags */
int v_numoutput; /* i: # of pending writes */
int v_writecount; /* i: ref count of writers */
+ int v_usecount; /* i: use count */
int v_holdcnt; /* i: page & buffer refs */
- struct mount *v_mount; /* v: ptr to vfs we are in */
- int (**v_op)(void *); /* :: vnode operations vector */
struct buflists v_cleanblkhd; /* x: clean blocklist head */
struct buflists v_dirtyblkhd; /* x: dirty blocklist head */
+
+ /*
+ * The remaining items are largely stable.
+ */
+ int v_vflag /* v: VV_* flags */
+ __aligned(COHERENCY_UNIT);
+ struct mount *v_mount; /* v: ptr to vfs we are in */
+ int (**v_op)(void *); /* :: vnode operations vector */
union {
struct mount *vu_mountedhere;/* v: ptr to vfs (VDIR) */
struct socket *vu_socket; /* v: unix ipc (VSOCK) */
@@ -160,7 +175,6 @@ struct vnode {
void *v_data; /* :: private data for fs */
struct klist v_klist; /* i: notes attached to vnode */
};
-#define v_usecount v_uobj.uo_refs
#define v_interlock v_uobj.vmobjlock
#define v_mountedhere v_un.vu_mountedhere
#define v_socket v_un.vu_socket
@@ -320,36 +334,11 @@ extern const int vttoif_tab[];
#define VDEAD_NOWAIT 0x0001 /* vdead_check: do not sleep */
void holdrelel(struct vnode *);
+void holdrele(struct vnode *);
void vholdl(struct vnode *);
+void vhold(struct vnode *);
void vref(struct vnode *);
-static __inline void holdrele(struct vnode *) __unused;
-static __inline void vhold(struct vnode *) __unused;
-
-/*
- * decrease buf or page ref
- */
-static __inline void
-holdrele(struct vnode *vp)
-{
-
- mutex_enter(vp->v_interlock);
- holdrelel(vp);
- mutex_exit(vp->v_interlock);
-}
-
-/*
- * increase buf or page ref
- */
-static __inline void
-vhold(struct vnode *vp)
-{
-
- mutex_enter(vp->v_interlock);
- vholdl(vp);
- mutex_exit(vp->v_interlock);
-}
-
#define NULLVP ((struct vnode *)NULL)
static __inline void
Index: src/sys/sys/vnode_impl.h
diff -u src/sys/sys/vnode_impl.h:1.19.2.4 src/sys/sys/vnode_impl.h:1.19.2.5
--- src/sys/sys/vnode_impl.h:1.19.2.4 Fri Jan 17 22:26:26 2020
+++ src/sys/sys/vnode_impl.h Fri Jan 24 16:05:23 2020
@@ -1,4 +1,4 @@
-/* $NetBSD: vnode_impl.h,v 1.19.2.4 2020/01/17 22:26:26 ad Exp $ */
+/* $NetBSD: vnode_impl.h,v 1.19.2.5 2020/01/24 16:05:23 ad Exp $ */
/*-
* Copyright (c) 2016, 2019, 2020 The NetBSD Foundation, Inc.
@@ -57,26 +57,58 @@ struct vcache_key {
* Reading or writing any of these items requires holding the appropriate
* lock. Field markings and the corresponding locks:
*
+ * - stable throughout the life of the vnode
* c vcache_lock
* d vdrain_lock
* i v_interlock
+ * l vi_nc_listlock
* m mnt_vnodelock
- * n managed by vfs_cache: see above
+ * n vi_nc_lock
+ * n,l vi_nc_lock + vi_nc_listlock to modify
* s syncer_data_lock
*/
struct vnode_impl {
struct vnode vi_vnode;
- enum vnode_state vi_state; /* i: current state */
- struct vnodelst *vi_lrulisthd; /* d: current lru list head */
- TAILQ_ENTRY(vnode_impl) vi_lrulist; /* d: lru list */
- struct nchnode *vi_ncache; /* n: namecache state */
- int vi_synclist_slot; /* s: synclist slot index */
- int vi_lrulisttm; /* i: time of lru enqueue */
- TAILQ_ENTRY(vnode_impl) vi_synclist; /* s: vnodes with dirty bufs */
- TAILQ_ENTRY(vnode_impl) vi_mntvnodes; /* m: vnodes for mount point */
- SLIST_ENTRY(vnode_impl) vi_hash; /* c: vnode cache list */
- krwlock_t *vi_lock; /* -: lock for this vnode */
- struct vcache_key vi_key; /* c: vnode cache key */
+
+ /*
+ * Largely stable data.
+ */
+ struct vcache_key vi_key; /* c vnode cache key */
+
+ /*
+ * Namecache. Give it a separate line so activity doesn't impinge
+ * on the stable stuff.
+ */
+ rb_tree_t vi_nc_tree /* n namecache tree */
+ __aligned(COHERENCY_UNIT);
+ TAILQ_HEAD(,namecache) vi_nc_list; /* l namecaches (parent) */
+ mode_t vi_nc_mode; /* n,l cached mode or VNOVAL */
+ uid_t vi_nc_uid; /* n,l cached UID or VNOVAL */
+ gid_t vi_nc_gid; /* n,l cached GID or VNOVAL */
+ uint32_t vi_nc_spare; /* - spare (padding) */
+
+ /*
+ * vnode cache, LRU and syncer. This all changes with some
+ * regularity so keep it together.
+ */
+ struct vnodelst *vi_lrulisthd /* d current lru list head */
+ __aligned(COHERENCY_UNIT);
+ TAILQ_ENTRY(vnode_impl) vi_lrulist; /* d lru list */
+ int vi_synclist_slot; /* s synclist slot index */
+ int vi_lrulisttm; /* i time of lru enqueue */
+ TAILQ_ENTRY(vnode_impl) vi_synclist; /* s vnodes with dirty bufs */
+ SLIST_ENTRY(vnode_impl) vi_hash; /* c vnode cache list */
+ enum vnode_state vi_state; /* i current state */
+
+ /*
+ * Locks and expensive to access items which can be expected to
+ * generate a cache miss.
+ */
+ krwlock_t vi_lock /* - lock for this vnode */
+ __aligned(COHERENCY_UNIT);
+ krwlock_t vi_nc_lock; /* - lock on node */
+ krwlock_t vi_nc_listlock; /* - lock on nn_list */
+ TAILQ_ENTRY(vnode_impl) vi_mntvnodes; /* m vnodes for mount point */
};
typedef struct vnode_impl vnode_impl_t;
