Move the g_stat struct to its own .h file, we will export it to other code.

Insted of embedding a struct g_stat in consumers and providers, merely
include a pointer.

Remove a couple of <sys/time.h> includes now unneeded.

Add a special allocator for struct g_stat.  This allocator will allocate
entire pages and hand out g_stat functions from there.  The "id" field
indicates free/used status.

Add "/dev/geom.stats" device driver whic exports the pages from the
allocator to userland with mmap(2) in read-only mode.

This mmap(2) interface should be considered a non-public interface and
the functions in libgeom (not yet committed) should be used to access
the statistics data.

sys/conf/files

@@ -889,6 +889,7 @@ geom/geom_mbr.c		optional geom_mbr
 geom/geom_mirror.c	optional geom_mirror
 geom/geom_pc98.c	optional geom_pc98
 geom/geom_slice.c	standard
+geom/geom_stats.c	standard
 geom/geom_subr.c	standard
 geom/geom_sunlabel.c	optional geom_sunlabel
 geom/geom_vol_ffs.c	optional geom_vol

sys/geom/bde/g_bde_lock.c

@@ -41,7 +41,6 @@
 #include <sys/stdint.h>
 #include <sys/lock.h>
 #include <sys/mutex.h>
-#include <sys/time.h>
 #include <sys/md5.h>
 
 #ifdef _KERNEL

sys/geom/bde/g_bde_work.c

@@ -67,7 +67,6 @@
 #include <sys/systm.h>
 #include <sys/kernel.h>
 #include <sys/sysctl.h>
-#include <sys/time.h>
 #include <sys/proc.h>
 #include <sys/kthread.h>
 

sys/geom/geom.h

@@ -58,6 +58,7 @@ struct g_geom;
 struct g_consumer;
 struct g_provider;
 struct g_event;
+struct g_stat;
 struct thread;
 struct bio;
 struct sbuf;
@@ -135,28 +136,6 @@ struct g_bioq {
 	int			bio_queue_length;
 };
 
-/*
- * A g_stat contains the statistics we collect on consumers and
- * providers.
- */
-struct g_stat {
-	void		*id;
-	uint64_t	nop;
-	uint64_t	nend;
-	struct bintime	it;
-	struct bintime	wentidle;
-	struct {
-		uint64_t	nop;
-		uint64_t	nbyte;
-		uint64_t	nmem;
-		uint64_t	nerr;
-		struct bintime	dt;
-	} ops[3];
-#define G_STAT_IDX_READ		0
-#define G_STAT_IDX_WRITE	1
-#define G_STAT_IDX_DELETE	2
-};
-
 /*
  * A g_consumer is an attachment point for a g_provider.  One g_consumer
  * can only be attached to one g_provider, but multiple g_consumers
@@ -172,7 +151,7 @@ struct g_consumer {
 	int			acr, acw, ace;
 	struct g_event		*event;
 	int			spoiled;
-	struct g_stat		stat;
+	struct g_stat		*stat;
 };
 
 /*
@@ -191,7 +170,7 @@ struct g_provider {
 	u_int			index;
 	off_t			mediasize;
 	u_int			sectorsize;
-	struct g_stat		stat;
+	struct g_stat		*stat;
 };
 
 /*

sys/geom/geom_dev.c

@@ -50,6 +50,7 @@
 #include <sys/fcntl.h>
 #include <geom/geom.h>
 #include <geom/geom_int.h>
+#include <geom/geom_stats.h>
 #include <machine/limits.h>
 
 static d_open_t		g_dev_open;
@@ -428,7 +429,7 @@ g_dev_orphan(struct g_consumer *cp)
 	gp = cp->geom;
 	g_trace(G_T_TOPOLOGY, "g_dev_orphan(%p(%s))", cp, gp->name);
 	g_topology_assert();
-	if (cp->stat.nop != cp->stat.nend)	/* XXX ? */
+	if (cp->stat->nop != cp->stat->nend)	/* XXX ? */
 		return;
 	dev = gp->softc;
 	if (dev->si_flags & SI_DUMPDEV)

sys/geom/geom_int.h

@@ -100,3 +100,8 @@ void g_io_schedule_up(struct thread *tp);
 
 /* geom_kern.c / geom_kernsim.c */
 void g_init(void);
+
+/* geom_stats.c */
+void g_stat_init(void);
+struct g_stat *g_stat_new(void *id);
+void g_stat_delete(struct g_stat *);

sys/geom/geom_io.c

@@ -55,6 +55,7 @@
 #include <sys/errno.h>
 #include <geom/geom.h>
 #include <geom/geom_int.h>
+#include <geom/geom_stats.h>
 
 static struct g_bioq g_bio_run_down;
 static struct g_bioq g_bio_run_up;
@@ -278,25 +279,25 @@ g_io_request(struct bio *bp, struct g_consumer *cp)
 	if (g_collectstats) {
 		/* Collect statistics */
 		binuptime(&bp->bio_t0);
-		if (cp->stat.nop == cp->stat.nend) {   
+		if (cp->stat->nop == cp->stat->nend) {   
 			/* Consumer is idle */
 			bt = bp->bio_t0;
-			bintime_sub(&bt, &cp->stat.wentidle);
+			bintime_sub(&bt, &cp->stat->wentidle);
-			bintime_add(&cp->stat.it, &bt);
+			bintime_add(&cp->stat->it, &bt);
-			if (pp->stat.nop == pp->stat.nend) {
+			if (pp->stat->nop == pp->stat->nend) {
 				/*
 				 * NB: Provider can only be idle if the
 				 * consumer is but we cannot trust them
 				 * to have gone idle at the same time.
 				 */
 				bt = bp->bio_t0;
-				bintime_sub(&bt, &pp->stat.wentidle);
+				bintime_sub(&bt, &pp->stat->wentidle);
-				bintime_add(&pp->stat.it, &bt);
+				bintime_add(&pp->stat->it, &bt);
 			}
 		}
 	}
-	cp->stat.nop++;
+	cp->stat->nop++;
-	pp->stat.nop++;
+	pp->stat->nop++;
 
 	/* Pass it on down. */
 	g_trace(G_T_BIO, "bio_request(%p) from %p(%s) to %p(%s) cmd %d",
@@ -339,29 +340,29 @@ g_io_deliver(struct bio *bp, int error)
 	/* Collect statistics */
 	if (g_collectstats) {
 		binuptime(&t1);
-		pp->stat.wentidle = t1;
+		pp->stat->wentidle = t1;
-		cp->stat.wentidle = t1;
+		cp->stat->wentidle = t1;
 
 		if (idx >= 0) {
 			bintime_sub(&t1, &bp->bio_t0);
-			bintime_add(&cp->stat.ops[idx].dt, &t1);
+			bintime_add(&cp->stat->ops[idx].dt, &t1);
-			bintime_add(&pp->stat.ops[idx].dt, &t1);
+			bintime_add(&pp->stat->ops[idx].dt, &t1);
-			pp->stat.ops[idx].nbyte += bp->bio_completed;
+			pp->stat->ops[idx].nbyte += bp->bio_completed;
-			cp->stat.ops[idx].nbyte += bp->bio_completed;
+			cp->stat->ops[idx].nbyte += bp->bio_completed;
-			pp->stat.ops[idx].nop++;
+			pp->stat->ops[idx].nop++;
-			cp->stat.ops[idx].nop++;
+			cp->stat->ops[idx].nop++;
 			if (error == ENOMEM) {
-				cp->stat.ops[idx].nmem++;
+				cp->stat->ops[idx].nmem++;
-				pp->stat.ops[idx].nmem++;
+				pp->stat->ops[idx].nmem++;
 			} else if (error != 0) {
-				cp->stat.ops[idx].nerr++;
+				cp->stat->ops[idx].nerr++;
-				pp->stat.ops[idx].nerr++;
+				pp->stat->ops[idx].nerr++;
 			}
 		}
 	}
 
-	pp->stat.nend++; /* In reverse order of g_io_request() */
+	pp->stat->nend++; /* In reverse order of g_io_request() */
-	cp->stat.nend++;
+	cp->stat->nend++;
 
 	if (error == ENOMEM) {
 		printf("ENOMEM %p on %p(%s)\n", bp, pp, pp->name);

sys/geom/geom_kern.c

@@ -49,6 +49,7 @@
 #include <sys/sbuf.h>
 #include <geom/geom.h>
 #include <geom/geom_int.h>
+#include <geom/geom_stats.h>
 
 MALLOC_DEFINE(M_GEOM, "GEOM", "Geom data structures");
 
@@ -154,6 +155,7 @@ g_init(void)
 {
 	printf("Initializing GEOMetry subsystem\n");
 	sx_init(&topology_lock, "GEOM topology");
+	g_stat_init();
 	g_io_init();
 	g_event_init();
 	mtx_lock(&Giant);

sys/geom/geom_stats.c

@@ -0,0 +1,145 @@
+/*-
+ * Copyright (c) 2002 Poul-Henning Kamp
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. The names of the authors may not be used to endorse or promote
+ *    products derived from this software without specific prior written
+ *    permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * $FreeBSD$
+ */
+
+#include "opt_geom.h"
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/kernel.h>
+#include <sys/sysctl.h>
+#include <sys/bio.h>
+#include <sys/conf.h>
+#include <sys/disk.h>
+#include <sys/malloc.h>
+#include <sys/sysctl.h>
+#include <sys/stdint.h>
+#include <vm/vm.h>
+#include <vm/pmap.h>
+
+#include <sys/lock.h>
+#include <sys/mutex.h>
+#include <geom/geom.h>
+#include <geom/geom_int.h>
+#include <geom/geom_stats.h>
+
+#define statsperpage (PAGE_SIZE / sizeof(struct g_stat))
+
+struct statspage {
+	TAILQ_ENTRY(statspage)	list;
+	struct g_stat		*stat;
+	u_int			nfree;
+};
+
+static TAILQ_HEAD(, statspage)	pagelist = TAILQ_HEAD_INITIALIZER(pagelist);
+
+struct g_stat *
+g_stat_new(void *id)
+{
+	struct g_stat *gsp;
+	struct statspage *spp;
+	u_int u;
+
+	g_topology_assert();
+	TAILQ_FOREACH(spp, &pagelist, list) {
+		if (spp->nfree > 0)
+			break;
+	}
+	if (spp == NULL) {
+		spp = g_malloc(sizeof *spp, M_ZERO);
+		TAILQ_INSERT_TAIL(&pagelist, spp, list);
+		spp->stat = g_malloc(PAGE_SIZE, M_ZERO);
+		printf("allocate another stats-page %p\n", spp->stat);
+		spp->nfree = statsperpage;
+	}
+	gsp = spp->stat;
+	for (u = 0; u < statsperpage; u++) {
+		if (gsp->id == NULL)
+			break;
+		gsp++;
+	}
+	spp->nfree--;
+	gsp->id = id;
+	return (gsp);
+}
+
+void
+g_stat_delete(struct g_stat *gsp)
+{
+	struct statspage *spp;
+
+	bzero(gsp, sizeof *gsp);
+	TAILQ_FOREACH(spp, &pagelist, list) {
+		if (gsp >= spp->stat && gsp < (spp->stat + statsperpage)) {
+			spp->nfree++;
+			return;
+		}
+	}
+}
+
+static d_mmap_t g_stat_mmap;
+
+static struct cdevsw geom_stats_cdevsw = {
+	/* open */	nullopen,
+	/* close */	nullclose,
+	/* read */	noread,
+	/* write */	nowrite,
+	/* ioctl */	noioctl,
+	/* poll */	nopoll,
+	/* mmap */	g_stat_mmap,
+	/* strtegy */	nostrategy,
+	/* name */	"g_stats",
+	/* maj */	GEOM_MAJOR,
+	/* dump */	nodump,
+	/* psize */	nopsize,
+	/* flags */	0,
+};
+
+static int
+g_stat_mmap(dev_t dev, vm_offset_t offset, int nprot)
+{
+	struct statspage *spp;
+
+	if (nprot != VM_PROT_READ)
+		return (-1);
+	TAILQ_FOREACH(spp, &pagelist, list) {
+		if (offset == 0)
+			return (vtophys(spp->stat) >> PAGE_SHIFT);
+		offset -= PAGE_SIZE;
+	}
+	return (-1);
+}
+
+void
+g_stat_init(void)
+{
+	make_dev(&geom_stats_cdevsw, GEOM_MINOR_STATS,
+	    UID_ROOT, GID_WHEEL, 0400, "geom.stats");
+}

sys/geom/geom_stats.h

@@ -0,0 +1,56 @@
+/*-
+ * Copyright (c) 2002 Poul-Henning Kamp
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. The names of the authors may not be used to endorse or promote
+ *    products derived from this software without specific prior written
+ *    permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * $FreeBSD$
+ */
+
+#ifndef _GEOM_GEOM_STATS_H_
+#define _GEOM_GEOM_STATS_H_
+
+/*
+ * A g_stat contains the statistics we collect on consumers and
+ * providers.
+ */
+struct g_stat {
+	void		*id;
+	uint64_t	nop;
+	uint64_t	nend;
+	struct bintime	it;
+	struct bintime	wentidle;
+	struct {
+		uint64_t	nop;
+		uint64_t	nbyte;
+		uint64_t	nmem;
+		uint64_t	nerr;
+		struct bintime	dt;
+	} ops[3];
+#define G_STAT_IDX_READ		0
+#define G_STAT_IDX_WRITE	1
+#define G_STAT_IDX_DELETE	2
+};
+
+#endif /* _GEOM_GEOM_STATS_H_ */

sys/geom/geom_subr.c

@@ -60,6 +60,7 @@
 #include <sys/sbuf.h>
 #include <geom/geom.h>
 #include <geom/geom_int.h>
+#include <geom/geom_stats.h>
 #include <machine/stdarg.h>
 
 struct class_list_head g_classes = LIST_HEAD_INITIALIZER(g_classes);
@@ -145,7 +146,7 @@ g_new_consumer(struct g_geom *gp)
 	cp = g_malloc(sizeof *cp, M_ZERO);
 	cp->protect = 0x020016602;
 	cp->geom = gp;
-	cp->stat.id = cp;
+	cp->stat = g_stat_new(cp);
 	LIST_INSERT_HEAD(&gp->consumer, cp, consumer);
 	return(cp);
 }
@@ -162,6 +163,7 @@ g_destroy_consumer(struct g_consumer *cp)
 	KASSERT (cp->acw == 0, ("g_destroy_consumer with acw"));
 	KASSERT (cp->ace == 0, ("g_destroy_consumer with ace"));
 	LIST_REMOVE(cp, consumer);
+	g_stat_delete(cp->stat);
 	g_free(cp);
 }
 
@@ -185,7 +187,7 @@ g_new_providerf(struct g_geom *gp, const char *fmt, ...)
 	LIST_INIT(&pp->consumers);
 	pp->error = ENXIO;
 	pp->geom = gp;
-	pp->stat.id = pp;
+	pp->stat = g_stat_new(pp);
 	LIST_INSERT_HEAD(&gp->provider, pp, provider);
 	g_nproviders++;
 	g_post_event(EV_NEW_PROVIDER, NULL, NULL, pp, NULL);
@@ -216,6 +218,7 @@ g_destroy_provider(struct g_provider *pp)
 	g_nproviders--;
 	LIST_REMOVE(pp, provider);
 	gp = pp->geom;
+	g_stat_delete(pp->stat);
 	g_free(pp);
 	if (!(gp->flags & G_GEOM_WITHER))
 		return;
@@ -329,7 +332,8 @@ g_detach(struct g_consumer *cp)
 	KASSERT(cp->acr == 0, ("detach but nonzero acr"));
 	KASSERT(cp->acw == 0, ("detach but nonzero acw"));
 	KASSERT(cp->ace == 0, ("detach but nonzero ace"));
-	KASSERT(cp->stat.nop == cp->stat.nend, ("detach with active requests"));
+	KASSERT(cp->stat->nop == cp->stat->nend,
+	    ("detach with active requests"));
 	pp = cp->provider;
 	LIST_REMOVE(cp, consumers);
 	cp->provider = NULL;