patch-2.4.25 linux-2.4.25/fs/xfs/support/ktrace.c

• Lines: 354
• Date: 2004-02-18 05:36:32.000000000 -0800
• Orig file: linux-2.4.24/fs/xfs/support/ktrace.c
• Orig date: 1969-12-31 16:00:00.000000000 -0800

diff -urN linux-2.4.24/fs/xfs/support/ktrace.c linux-2.4.25/fs/xfs/support/ktrace.c
@@ -0,0 +1,353 @@
+/*
+ * Copyright (c) 2000-2003 Silicon Graphics, Inc.  All Rights Reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of version 2 of the GNU General Public License as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it would be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+ *
+ * Further, this software is distributed without any warranty that it is
+ * free of the rightful claim of any third person regarding infringement
+ * or the like.  Any license provided herein, whether implied or
+ * otherwise, applies only to this software file.  Patent licenses, if
+ * any, provided herein do not apply to combinations of this program with
+ * other software, or any other product whatsoever.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write the Free Software Foundation, Inc., 59
+ * Temple Place - Suite 330, Boston MA 02111-1307, USA.
+ *
+ * Contact information: Silicon Graphics, Inc., 1600 Amphitheatre Pkwy,
+ * Mountain View, CA  94043, or:
+ *
+ * http://www.sgi.com
+ *
+ * For further information regarding this notice, see:
+ *
+ * http://oss.sgi.com/projects/GenInfo/SGIGPLNoticeExplan/
+ */
+
+#include <linux/types.h>
+#include <linux/slab.h>
+
+#include <xfs_types.h>
+#include "kmem.h"
+#include "spin.h"
+#include "debug.h"
+#include "ktrace.h"
+
+static kmem_zone_t *ktrace_hdr_zone;
+static kmem_zone_t *ktrace_ent_zone;
+static int          ktrace_zentries;
+
+void
+ktrace_init(int zentries)
+{
+	ktrace_zentries = zentries;
+
+	ktrace_hdr_zone = kmem_zone_init(sizeof(ktrace_t),
+					"ktrace_hdr");
+	ASSERT(ktrace_hdr_zone);
+
+	ktrace_ent_zone = kmem_zone_init(ktrace_zentries
+					* sizeof(ktrace_entry_t),
+					"ktrace_ent");
+	ASSERT(ktrace_ent_zone);
+}
+
+void
+ktrace_uninit(void)
+{
+	kmem_cache_destroy(ktrace_hdr_zone);
+	kmem_cache_destroy(ktrace_ent_zone);
+}
+
+/*
+ * ktrace_alloc()
+ *
+ * Allocate a ktrace header and enough buffering for the given
+ * number of entries.
+ */
+ktrace_t *
+ktrace_alloc(int nentries, int sleep)
+{
+	ktrace_t        *ktp;
+	ktrace_entry_t  *ktep;
+
+	ktp = (ktrace_t*)kmem_zone_alloc(ktrace_hdr_zone, sleep);
+
+	if (ktp == (ktrace_t*)NULL) {
+		/*
+		 * KM_SLEEP callers don't expect failure.
+		 */
+		if (sleep & KM_SLEEP)
+			panic("ktrace_alloc: NULL memory on KM_SLEEP request!");
+
+		return NULL;
+	}
+
+	/*
+	 * Special treatment for buffers with the ktrace_zentries entries
+	 */
+	if (nentries == ktrace_zentries) {
+		ktep = (ktrace_entry_t*)kmem_zone_zalloc(ktrace_ent_zone,
+							    sleep);
+	} else {
+		ktep = (ktrace_entry_t*)kmem_zalloc((nentries * sizeof(*ktep)),
+							    sleep);
+	}
+
+	if (ktep == NULL) {
+		/*
+		 * KM_SLEEP callers don't expect failure.
+		 */
+		if (sleep & KM_SLEEP)
+			panic("ktrace_alloc: NULL memory on KM_SLEEP request!");
+
+		kmem_free(ktp, sizeof(*ktp));
+
+		return NULL;
+	}
+
+	spinlock_init(&(ktp->kt_lock), "kt_lock");
+
+	ktp->kt_entries  = ktep;
+	ktp->kt_nentries = nentries;
+	ktp->kt_index    = 0;
+	ktp->kt_rollover = 0;
+	return ktp;
+}
+
+
+/*
+ * ktrace_free()
+ *
+ * Free up the ktrace header and buffer.  It is up to the caller
+ * to ensure that no-one is referencing it.
+ */
+void
+ktrace_free(ktrace_t *ktp)
+{
+	int     entries_size;
+
+	if (ktp == (ktrace_t *)NULL)
+		return;
+
+	spinlock_destroy(&ktp->kt_lock);
+
+	/*
+	 * Special treatment for the Vnode trace buffer.
+	 */
+	if (ktp->kt_nentries == ktrace_zentries) {
+		kmem_zone_free(ktrace_ent_zone, ktp->kt_entries);
+	} else {
+		entries_size = (int)(ktp->kt_nentries * sizeof(ktrace_entry_t));
+
+		kmem_free(ktp->kt_entries, entries_size);
+	}
+
+	kmem_zone_free(ktrace_hdr_zone, ktp);
+}
+
+
+/*
+ * Enter the given values into the "next" entry in the trace buffer.
+ * kt_index is always the index of the next entry to be filled.
+ */
+void
+ktrace_enter(
+	ktrace_t        *ktp,
+	void            *val0,
+	void            *val1,
+	void            *val2,
+	void            *val3,
+	void            *val4,
+	void            *val5,
+	void            *val6,
+	void            *val7,
+	void            *val8,
+	void            *val9,
+	void            *val10,
+	void            *val11,
+	void            *val12,
+	void            *val13,
+	void            *val14,
+	void            *val15)
+{
+	static lock_t   wrap_lock = SPIN_LOCK_UNLOCKED;
+	unsigned long	flags;
+	int             index;
+	ktrace_entry_t  *ktep;
+
+	ASSERT(ktp != NULL);
+
+	/*
+	 * Grab an entry by pushing the index up to the next one.
+	 */
+	spin_lock_irqsave(&wrap_lock, flags);
+	index = ktp->kt_index;
+	if (++ktp->kt_index == ktp->kt_nentries)
+		ktp->kt_index = 0;
+	spin_unlock_irqrestore(&wrap_lock, flags);
+
+	if (!ktp->kt_rollover && index == ktp->kt_nentries - 1)
+		ktp->kt_rollover = 1;
+
+	ASSERT((index >= 0) && (index < ktp->kt_nentries));
+
+	ktep = &(ktp->kt_entries[index]);
+
+	ktep->val[0]  = val0;
+	ktep->val[1]  = val1;
+	ktep->val[2]  = val2;
+	ktep->val[3]  = val3;
+	ktep->val[4]  = val4;
+	ktep->val[5]  = val5;
+	ktep->val[6]  = val6;
+	ktep->val[7]  = val7;
+	ktep->val[8]  = val8;
+	ktep->val[9]  = val9;
+	ktep->val[10] = val10;
+	ktep->val[11] = val11;
+	ktep->val[12] = val12;
+	ktep->val[13] = val13;
+	ktep->val[14] = val14;
+	ktep->val[15] = val15;
+}
+
+/*
+ * Return the number of entries in the trace buffer.
+ */
+int
+ktrace_nentries(
+	ktrace_t        *ktp)
+{
+	if (ktp == NULL) {
+		return 0;
+	}
+
+	return (ktp->kt_rollover ? ktp->kt_nentries : ktp->kt_index);
+}
+
+/*
+ * ktrace_first()
+ *
+ * This is used to find the start of the trace buffer.
+ * In conjunction with ktrace_next() it can be used to
+ * iterate through the entire trace buffer.  This code does
+ * not do any locking because it is assumed that it is called
+ * from the debugger.
+ *
+ * The caller must pass in a pointer to a ktrace_snap
+ * structure in which we will keep some state used to
+ * iterate through the buffer.  This state must not touched
+ * by any code outside of this module.
+ */
+ktrace_entry_t *
+ktrace_first(ktrace_t   *ktp, ktrace_snap_t     *ktsp)
+{
+	ktrace_entry_t  *ktep;
+	int             index;
+	int             nentries;
+
+	if (ktp->kt_rollover)
+		index = ktp->kt_index;
+	else
+		index = 0;
+
+	ktsp->ks_start = index;
+	ktep = &(ktp->kt_entries[index]);
+
+	nentries = ktrace_nentries(ktp);
+	index++;
+	if (index < nentries) {
+		ktsp->ks_index = index;
+	} else {
+		ktsp->ks_index = 0;
+		if (index > nentries)
+			ktep = NULL;
+	}
+	return ktep;
+}
+
+/*
+ * ktrace_next()
+ *
+ * This is used to iterate through the entries of the given
+ * trace buffer.  The caller must pass in the ktrace_snap_t
+ * structure initialized by ktrace_first().  The return value
+ * will be either a pointer to the next ktrace_entry or NULL
+ * if all of the entries have been traversed.
+ */
+ktrace_entry_t *
+ktrace_next(
+	ktrace_t        *ktp,
+	ktrace_snap_t   *ktsp)
+{
+	int             index;
+	ktrace_entry_t  *ktep;
+
+	index = ktsp->ks_index;
+	if (index == ktsp->ks_start) {
+		ktep = NULL;
+	} else {
+		ktep = &ktp->kt_entries[index];
+	}
+
+	index++;
+	if (index == ktrace_nentries(ktp)) {
+		ktsp->ks_index = 0;
+	} else {
+		ktsp->ks_index = index;
+	}
+
+	return ktep;
+}
+
+/*
+ * ktrace_skip()
+ *
+ * Skip the next "count" entries and return the entry after that.
+ * Return NULL if this causes us to iterate past the beginning again.
+ */
+ktrace_entry_t *
+ktrace_skip(
+	ktrace_t        *ktp,
+	int             count,
+	ktrace_snap_t   *ktsp)
+{
+	int             index;
+	int             new_index;
+	ktrace_entry_t  *ktep;
+	int             nentries = ktrace_nentries(ktp);
+
+	index = ktsp->ks_index;
+	new_index = index + count;
+	while (new_index >= nentries) {
+		new_index -= nentries;
+	}
+	if (index == ktsp->ks_start) {
+		/*
+		 * We've iterated around to the start, so we're done.
+		 */
+		ktep = NULL;
+	} else if ((new_index < index) && (index < ktsp->ks_index)) {
+		/*
+		 * We've skipped past the start again, so we're done.
+		 */
+		ktep = NULL;
+		ktsp->ks_index = ktsp->ks_start;
+	} else {
+		ktep = &(ktp->kt_entries[new_index]);
+		new_index++;
+		if (new_index == nentries) {
+			ktsp->ks_index = 0;
+		} else {
+			ktsp->ks_index = new_index;
+		}
+	}
+	return ktep;
+}