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Index: sys/kern/vfs_subr.c
===================================================================
--- sys/kern/vfs_subr.c
+++ sys/kern/vfs_subr.c
@@ -302,6 +302,15 @@
SYSCTL_INT(_debug, OID_AUTO, rush_requests, CTLFLAG_RW, &stat_rush_requests, 0,
"Number of times I/O speeded up (rush requests)");
+#define VDBATCH_SIZE 8
+struct vdbatch {
+ u_int index;
+ u_int count;
+ struct mtx lock;
+ struct vnode *tab[VDBATCH_SIZE];
+};
+DPCPU_DEFINE_STATIC(struct vdbatch, vd);
+
/*
* When shutting down the syncer, run it at four times normal speed.
*/
@@ -319,6 +328,8 @@
static int vstir; /* nonzero to stir non-free vnodes */
static volatile int vsmalltrigger = 8; /* pref to keep if > this many pages */
+static void vdbatch_dequeue(struct vnode *vp);
+
static int
sysctl_update_desiredvnodes(SYSCTL_HANDLER_ARGS)
{
@@ -498,6 +509,8 @@
*/
rangelock_init(&vp->v_rl);
+ vp->v_dbatchcpu = NOCPU;
+
mtx_lock(&vnode_list_mtx);
TAILQ_INSERT_BEFORE(vnode_list_marker, vp, v_vnodelist);
mtx_unlock(&vnode_list_mtx);
@@ -514,6 +527,7 @@
struct bufobj *bo;
vp = mem;
+ vdbatch_dequeue(vp);
mtx_lock(&vnode_list_mtx);
TAILQ_REMOVE(&vnode_list, vp, v_vnodelist);
mtx_unlock(&vnode_list_mtx);
@@ -548,8 +562,9 @@
static void
vntblinit(void *dummy __unused)
{
+ struct vdbatch *vd;
+ int cpu, physvnodes, virtvnodes;
u_int i;
- int physvnodes, virtvnodes;
/*
* Desiredvnodes is a function of the physical memory size and the
@@ -613,6 +628,12 @@
for (i = 1; i <= sizeof(struct vnode); i <<= 1)
vnsz2log++;
vnsz2log--;
+
+ CPU_FOREACH(cpu) {
+ vd = DPCPU_ID_PTR((cpu), vd);
+ bzero(vd, sizeof(*vd));
+ mtx_init(&vd->lock, "vdbatch", NULL, MTX_DEF);
+ }
}
SYSINIT(vfs, SI_SUB_VFS, SI_ORDER_FIRST, vntblinit, NULL);
@@ -3135,6 +3156,100 @@
#endif
}
+static void
+vdbatch_process(struct vdbatch *vd)
+{
+ struct vnode *vp;
+ int i;
+
+ mtx_assert(&vd->lock, MA_OWNED);
+
+ mtx_lock(&vnode_list_mtx);
+ for (i = 0; i < VDBATCH_SIZE; i++) {
+ vp = vd->tab[i];
+ if (vp == NULL)
+ continue;
+ TAILQ_REMOVE(&vnode_list, vp, v_vnodelist);
+ TAILQ_INSERT_TAIL(&vnode_list, vp, v_vnodelist);
+ MPASS(vp->v_dbatchcpu != NOCPU);
+ vp->v_dbatchcpu = NOCPU;
+ vd->tab[i] = NULL;
+ }
+ vd->index = 0;
+ vd->count = 0;
+ mtx_unlock(&vnode_list_mtx);
+}
+
+static void
+vdbatch_enqueue(struct vnode *vp)
+{
+ struct vdbatch *vd;
+ int i;
+
+ ASSERT_VI_LOCKED(vp, __func__);
+ VNASSERT(!VN_IS_DOOMED(vp), vp,
+ ("%s: deferring requeue of a doomed vnode", __func__));
+
+ if (vp->v_dbatchcpu != NOCPU) {
+ VI_UNLOCK(vp);
+ return;
+ }
+ /*
+ * A hack: pin us to the current CPU so that we know what to put in
+ * ->v_dbatchcpu.
+ */
+ sched_pin();
+ vd = DPCPU_PTR(vd);
+ mtx_lock(&vd->lock);
+ KASSERT(vd->index < VDBATCH_SIZE, ("%s: invalid index %u\n",
+ __func__, vd->index));
+ for (i = vd->index; i < VDBATCH_SIZE; i++) {
+ if (vd->tab[i] != NULL)
+ continue;
+ MPASS(curthread->td_pinned);
+ vp->v_dbatchcpu = curcpu;
+ vd->tab[i] = vp;
+ vd->index = i + 1;
+ vd->count++;
+ break;
+ }
+ KASSERT(vp->v_dbatchcpu != NOCPU,
+ ("%s: failed to fit the vnode (index %u, count %u)\n",
+ __func__, vd->index, vd->count));
+ VI_UNLOCK(vp);
+ sched_unpin();
+ KASSERT(vd->count <= VDBATCH_SIZE, ("%s: invalid batch count %u\n",
+ __func__, vd->count));
+ if (vd->count == VDBATCH_SIZE)
+ vdbatch_process(vd);
+ mtx_unlock(&vd->lock);
+}
+
+static void
+vdbatch_dequeue(struct vnode *vp)
+{
+ struct vdbatch *vd;
+ int i;
+ short cpu;
+
+ cpu = atomic_load_short(&vp->v_dbatchcpu);
+ if (cpu == NOCPU)
+ return;
+ vd = DPCPU_ID_PTR(cpu, vd);
+ mtx_lock(&vd->lock);
+ for (i = 0; i < VDBATCH_SIZE; i++) {
+ if (vd->tab[i] != vp)
+ continue;
+ vp->v_dbatchcpu = NOCPU;
+ vd->tab[i] = NULL;
+ if (i < vd->index)
+ vd->index = i;
+ vd->count--;
+ break;
+ }
+ mtx_unlock(&vd->lock);
+}
+
/*
* Drop the hold count of the vnode. If this is the last reference to
* the vnode we place it on the free list unless it has been vgone'd
@@ -3172,12 +3287,8 @@
mp->mnt_dirtyvnodelistsize--;
mtx_unlock(&mp->mnt_listmtx);
}
- mtx_lock(&vnode_list_mtx);
- TAILQ_REMOVE(&vnode_list, vp, v_vnodelist);
- TAILQ_INSERT_TAIL(&vnode_list, vp, v_vnodelist);
- mtx_unlock(&vnode_list_mtx);
atomic_add_long(&freevnodes, 1);
- VI_UNLOCK(vp);
+ vdbatch_enqueue(vp);
}
void
Index: sys/sys/vnode.h
===================================================================
--- sys/sys/vnode.h
+++ sys/sys/vnode.h
@@ -171,7 +171,8 @@
u_int v_usecount; /* I ref count of users */
u_int v_iflag; /* i vnode flags (see below) */
u_int v_vflag; /* v vnode flags */
- u_int v_mflag; /* l mnt-specific vnode flags */
+ u_short v_mflag; /* l mnt-specific vnode flags */
+ short v_dbatchcpu; /* i LRU requeue deferral batch */
int v_writecount; /* I ref count of writers or
(negative) text users */
u_int v_hash;

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