1 files changed, 226 insertions, 0 deletions
diff --git a/usr/src/cmd/mdb/common/modules/genunix/dist.c b/usr/src/cmd/mdb/common/modules/genunix/dist.c
new file mode 100644
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+++ b/usr/src/cmd/mdb/common/modules/genunix/dist.c
@@ -0,0 +1,226 @@
+/*
+ * CDDL HEADER START
+ *
+ * The contents of this file are subject to the terms of the
+ * Common Development and Distribution License (the "License").
+ * You may not use this file except in compliance with the License.
+ *
+ * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
+ * or http://www.opensolaris.org/os/licensing.
+ * See the License for the specific language governing permissions
+ * and limitations under the License.
+ *
+ * When distributing Covered Code, include this CDDL HEADER in each
+ * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
+ * If applicable, add the following below this CDDL HEADER, with the
+ * fields enclosed by brackets "[]" replaced with your own identifying
+ * information: Portions Copyright [yyyy] [name of copyright owner]
+ *
+ * CDDL HEADER END
+ */
+/*
+ * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
+ * Use is subject to license terms.
+ */
+
+#pragma ident	"%Z%%M%	%I%	%E% SMI"
+
+#include <mdb/mdb_modapi.h>
+#ifndef	_KMDB
+#include <math.h>
+#endif
+
+#include "dist.h"
+
+/*
+ * Divides the given range (inclusive at both endpoints) evenly into the given
+ * number of buckets, adding one bucket at the end that is one past the end of
+ * the range. The returned buckets will be automatically freed when the dcmd
+ * completes or is forcibly aborted.
+ */
+const int *
+dist_linear(int buckets, int beg, int end)
+{
+	int *out = mdb_alloc((buckets + 1) * sizeof (*out), UM_SLEEP | UM_GC);
+	int pos;
+	int dist = end - beg + 1;
+
+	for (pos = 0; pos < buckets; pos++)
+		out[pos] = beg + (pos * dist)/buckets;
+	out[buckets] = end + 1;
+
+	return (out);
+}
+
+/*
+ * We want the bins to be a constant ratio:
+ *
+ *	b_0	  = beg;
+ *	b_idx	  = b_{idx-1} * r;
+ *	b_buckets = end + 1;
+ *
+ * That is:
+ *
+ *	       buckets
+ *	beg * r        = end
+ *
+ * Which reduces to:
+ *
+ *		  buckets ___________________
+ *	      r = -------/ ((end + 1) / beg)
+ *
+ *		  log ((end + 1) / beg)
+ *	  log r = ---------------------
+ *		         buckets
+ *
+ *		   (log ((end + 1) / beg)) / buckets
+ *	      r = e
+ */
+/* ARGSUSED */
+const int *
+dist_geometric(int buckets, int beg, int end, int minbucketsize)
+{
+#ifdef	_KMDB
+	return (dist_linear(buckets, beg, end));
+#else
+	int *out = mdb_alloc((buckets + 1) * sizeof (*out), UM_SLEEP | UM_GC);
+
+	double r;
+	double b;
+	int idx = 0;
+	int last;
+	int begzero;
+
+	if (minbucketsize == 0)
+		minbucketsize = 1;
+
+	if (buckets == 1) {
+		out[0] = beg;
+		out[1] = end + 1;
+		return (out);
+	}
+
+	begzero = (beg == 0);
+	if (begzero)
+		beg = 1;
+
+	r = exp(log((double)(end + 1) / beg) / buckets);
+
+	/*
+	 * We've now computed r, using the previously derived formula.  We
+	 * now need to generate the array of bucket bounds.  There are
+	 * two major variables:
+	 *
+	 *	b	holds b_idx, the current index, as a double.
+	 *	last	holds the integer which goes into out[idx]
+	 *
+	 * Our job is to transform the smooth function b_idx, defined
+	 * above, into integer-sized buckets, with a specified minimum
+	 * bucket size.  Since b_idx is an exponentially growing function,
+	 * any inadequate buckets must be at the beginning.  To deal
+	 * with this, we make buckets of minimum size until b catches up
+	 * with last.
+	 *
+	 * A final wrinkle is that beg *can* be zero.  We compute r and b
+	 * as if beg was 1, then start last as 0.  This can lead to a bit
+	 * of oddness around the 0 bucket, but it's mostly reasonable.
+	 */
+
+	b = last = beg;
+	if (begzero)
+		last = 0;
+
+	for (idx = 0; idx < buckets; idx++) {
+		int next;
+
+		out[idx] = last;
+
+		b *= r;
+		next = (int)b;
+
+		if (next > last + minbucketsize - 1)
+			last = next;
+		else
+			last += minbucketsize;
+	}
+	out[buckets] = end + 1;
+
+	return (out);
+#endif
+}
+
+#define	NCHARS	50
+/*
+ * Print the distribution header with the given bucket label. The header is
+ * printed on a single line, and the label is assumed to fit within the given
+ * width (number of characters). The default label width when unspecified (0)
+ * is eleven characters. Optionally, a label other than "count" may be specified
+ * for the bucket counts.
+ */
+void
+dist_print_header(const char *label, int width, const char *count)
+{
+	int n;
+	const char *dist = " Distribution ";
+	char dashes[NCHARS + 1];
+
+	if (width == 0)
+		width = 11;
+
+	if (count == NULL)
+		count = "count";
+
+	n = (NCHARS - strlen(dist)) / 2;
+	(void) memset(dashes, '-', n);
+	dashes[n] = '\0';
+
+	mdb_printf("%*s  %s%s%s %s\n", width, label, dashes, dist, dashes,
+	    count);
+}
+
+/*
+ * Print one distribution bucket whose range is from distarray[i] inclusive to
+ * distarray[i + 1] exclusive by totalling counts in that index range.  The
+ * given total is assumed to be the sum of all elements in the counts array.
+ * Each bucket is labeled by its range in the form "first-last" (omit "-last" if
+ * the range is a single value) where first and last are integers, and last is
+ * one less than the first value of the next bucket range. The bucket label is
+ * assumed to fit within the given width (number of characters), which should
+ * match the width value passed to dist_print_header(). The default width when
+ * unspecified (0) is eleven characters.
+ */
+void
+dist_print_bucket(const int *distarray, int i, const uint_t *counts,
+    uint64_t total, int width)
+{
+	int b;				/* bucket range index */
+	int bb = distarray[i];		/* bucket begin */
+	int be = distarray[i + 1] - 1;	/* bucket end */
+	uint64_t count = 0;		/* bucket value */
+
+	int nats;
+	char ats[NCHARS + 1], spaces[NCHARS + 1];
+	char range[40];
+
+	if (width == 0)
+		width = 11;
+
+	if (total == 0)
+		total = 1;		/* avoid divide-by-zero */
+
+	for (b = bb; b <= be; b++)
+		count += counts[b];
+
+	nats = (NCHARS * count) / total;
+	(void) memset(ats, '@', nats);
+	ats[nats] = 0;
+	(void) memset(spaces, ' ', NCHARS - nats);
+	spaces[NCHARS - nats] = 0;
+
+	if (bb == be)
+		(void) mdb_snprintf(range, sizeof (range), "%d", bb);
+	else
+		(void) mdb_snprintf(range, sizeof (range), "%d-%d", bb, be);
+	mdb_printf("%*s |%s%s %lld\n", width, range, ats, spaces, count);
+}
+#undef NCHARS