Jan Kiszka wrote:
> Gilles Chanteperdrix wrote:
> > Jan Kiszka wrote:
> > > o instrument the xenomai exception handler with an ipipe_trace_freeze()
> > > (something which should be merged into SVN later)
> >
> > The I-pipe tracer as well as Linux NMI handling have the same issue
> > which is the cause for the exceptions 14: they rely on a correct
> > "current" to read the processor id. The first attached patch, to be
> > applied after the ipipe patch, add an ipipe_processor_id_notrace
> > function, which is called instead of raw_smp_processor_id() in the
> > second, I-pipe tracer, attached patch.
> >
>
> Ah, good point! But why not make the original __ipipe_*_cpuid functions
> non-traced? I don't think we would loose significant information.
The attached patches do that.
--
Gilles Chanteperdrix.
--- linux/arch/i386/kernel/ipipe-root.c~ 2006-04-13 17:11:19.000000000
+0200
+++ linux/arch/i386/kernel/ipipe-root.c 2006-04-13 17:26:59.000000000 +0200
@@ -85,13 +85,14 @@ static void __ipipe_null_handler(unsigne
#ifdef CONFIG_SMP
-static int __ipipe_boot_cpuid(void)
+static __attribute__((no_instrument_function)) int __ipipe_boot_cpuid(void)
{
return 0;
}
u8 __ipipe_apicid_2_cpu[IPIPE_NR_CPUS];
+#ifndef CONFIG_IPIPE_TRACE
static int __ipipe_hard_cpuid(void)
{
unsigned long flags;
@@ -102,6 +103,18 @@ static int __ipipe_hard_cpuid(void)
local_irq_restore_hw(flags);
return cpu;
}
+#else /* CONFIG_IPIPE_TRACE */
+static notrace int __ipipe_hard_cpuid(void)
+{
+ unsigned long flags;
+ int cpu;
+
+ local_irq_save_hw_notrace(flags);
+ cpu = __ipipe_apicid_2_cpu[GET_APIC_ID(apic_read(APIC_ID))];
+ local_irq_restore_hw_notrace(flags);
+ return cpu;
+}
+#endif /* CONFIG_IPIPE_TRACE */
int (*__ipipe_logical_cpuid)(void) = &__ipipe_boot_cpuid;
--- linux/include/asm-i386/ipipe.h~ 2006-04-13 17:11:19.000000000 +0200
+++ linux/include/asm-i386/ipipe.h 2006-04-13 17:14:24.000000000 +0200
@@ -97,7 +97,7 @@
#define IPIPE_CRITICAL_VECTOR 0xf9 /* Used by ipipe_critical_enter/exit()
*/
#define IPIPE_CRITICAL_IPI (IPIPE_CRITICAL_VECTOR - FIRST_EXTERNAL_VECTOR)
-static inline int ipipe_processor_id(void)
+static inline __attribute__((no_instrument_function)) int
ipipe_processor_id(void)
{
extern int (*__ipipe_logical_cpuid)(void);
return __ipipe_logical_cpuid();
--- common/kernel/ipipe/Kconfig
+++ /home/rpm/gna/adeos/ipipe/v2.6/common/kernel/ipipe/Kconfig.trace
2006-01-09 03:41:35.000000000 +0100
@@ -13,3 +13,24 @@ config IPIPE_STATS
Activate this option if you want runtime statistics to be collected
while the I-pipe is operating. This option adds a small overhead, but
is useful to detect unexpected latency spots.
+
+config IPIPE_TRACE
+ bool "Latency Tracing"
+ depends on IPIPE && PROC_FS
+ select FRAME_POINTER
+ default n
+ ---help---
+ Activate this option if you want to use per-function tracing of
+ the kernel. The tracer will collect data via instrumentation
+ features like the one below or with the help of explicite calls
+ of ipipe_trace_xxx(). See include/linux/ipipe_trace.h for the
+ in-kernel tracing API. The collected data and runtime control
+ is available via /proc/ipipe/trace/*.
+
+config IPIPE_TRACE_IRQSOFF
+ bool "Trace IRQs-off times"
+ depends on IPIPE_TRACE
+ default y
+ ---help---
+ Activate this option if I-pipe shall trace the longest path
+ with hard-IRQs switched off.
--- 2.6.16/Makefile 2006-03-20 06:53:29.000000000 +0100
+++ 2.6.16-ipipe/Makefile 2006-03-21 14:52:40.000000000 +0100
@@ -511,11 +511,15 @@ CFLAGS += $(call add-align,CONFIG_CC_AL
CFLAGS += $(call add-align,CONFIG_CC_ALIGN_LOOPS,-loops)
CFLAGS += $(call add-align,CONFIG_CC_ALIGN_JUMPS,-jumps)
+ifdef CONFIG_IPIPE_TRACE
+CFLAGS += -pg -fno-omit-frame-pointer $(call
cc-option,-fno-optimize-sibling-calls,)
+else
ifdef CONFIG_FRAME_POINTER
CFLAGS += -fno-omit-frame-pointer $(call
cc-option,-fno-optimize-sibling-calls,)
else
CFLAGS += -fomit-frame-pointer
endif
+endif
ifdef CONFIG_DEBUG_INFO
CFLAGS += -g
--- 2.6.16/include/linux/ipipe_trace.h 1970-01-01 01:00:00.000000000 +0100
+++ 2.6.16-ipipe/include/linux/ipipe_trace.h 2006-01-31 09:06:32.000000000
+0100
@@ -0,0 +1,37 @@
+/* -*- linux-c -*-
+ * include/linux/ipipe_trace.h
+ *
+ * Copyright (C) 2005 Luotao Fu.
+ * 2005 Jan Kiszka.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, Inc., 675 Mass Ave, Cambridge MA 02139,
+ * USA; either version 2 of the License, or (at your option) any later
+ * version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ */
+
+#ifndef _LINUX_IPIPE_TRACE_H
+#define _LINUX_IPIPE_TRACE_H
+
+void ipipe_trace_begin(unsigned long v);
+void ipipe_trace_end(unsigned long v);
+void ipipe_trace_freeze(unsigned long v);
+void ipipe_trace_special(unsigned char special_id, unsigned long v);
+
+int ipipe_trace_max_reset(void);
+int ipipe_trace_frozen_reset(void);
+
+void ipipe_trace_panic_freeze(void);
+void ipipe_trace_panic_dump(void);
+
+#endif /* !__LINUX_IPIPE_H */
--- 2.6.16/include/linux/linkage.h 2006-03-20 06:53:29.000000000 +0100
+++ 2.6.16-ipipe/include/linux/linkage.h 2006-03-21 14:53:07.000000000
+0100
@@ -51,4 +51,8 @@
#define fastcall
#endif
+#ifndef notrace
+#define notrace __attribute__((no_instrument_function))
+#endif
+
#endif
--- 2.6.16/kernel/ipipe/tracer.c 1970-01-01 01:00:00.000000000 +0100
+++ 2.6.16-ipipe/kernel/ipipe/tracer.c 2006-01-31 09:06:32.000000000 +0100
@@ -0,0 +1,1048 @@
+/* -*- linux-c -*-
+ * kernel/ipipe/tracer.c
+ *
+ * Copyright (C) 2005 Luotao Fu.
+ * 2005 Jan Kiszka.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, Inc., 675 Mass Ave, Cambridge MA 02139,
+ * USA; either version 2 of the License, or (at your option) any later
+ * version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/version.h>
+#include <linux/kallsyms.h>
+#include <linux/seq_file.h>
+#include <linux/proc_fs.h>
+#include <linux/ctype.h>
+#include <linux/ipipe_trace.h>
+#include <asm/uaccess.h>
+
+#define IPIPE_TRACE_PATHS 4
+#define IPIPE_DEFAULT_ACTIVE 0
+#define IPIPE_DEFAULT_MAX 1
+#define IPIPE_DEFAULT_FROZEN 2
+
+#define IPIPE_TRACE_POINTS 16*1024
+#define WRAP_POINT_NO(point) ((point) & (IPIPE_TRACE_POINTS-1))
+
+#define IPIPE_DEFAULT_PRE_TRACE 10
+#define IPIPE_DEFAULT_POST_TRACE 10
+#define IPIPE_DEFAULT_BACK_TRACE 30
+
+#define IPIPE_DELAY_NOTE 1000 /* in nanoseconds */
+#define IPIPE_DELAY_WARN 10000 /* in nanoseconds */
+
+#define IPIPE_TFLG_NMI_LOCK 0x0001
+#define IPIPE_TFLG_NMI_HIT 0x0002
+#define IPIPE_TFLG_NMI_FREEZE_REQ 0x0004
+
+#define IPIPE_TFLG_HWIRQ_OFF 0x0100
+#define IPIPE_TFLG_FREEZING 0x0200
+
+
+struct ipipe_trace_point{
+ short type;
+ short flags;
+ unsigned long eip;
+ unsigned long parent_eip;
+ unsigned long v;
+ unsigned long long timestamp;
+};
+
+struct ipipe_trace_path{
+ volatile int flags;
+ int dump_lock; /* separated from flags due to cross-cpu access */
+ int trace_pos; /* next point to fill */
+ int begin, end; /* finalised path begin and end */
+ int post_trace; /* non-zero when in post-trace phase */
+ unsigned long long length; /* max path length in cycles */
+ unsigned long nmi_saved_eip; /* for deferred requests from NMIs */
+ unsigned long nmi_saved_parent_eip;
+ unsigned long nmi_saved_v;
+ struct ipipe_trace_point point[IPIPE_TRACE_POINTS];
+} ____cacheline_aligned_in_smp;
+
+enum ipipe_trace_type
+{
+ IPIPE_TRACE_FN = 0,
+ IPIPE_TRACE_BEGIN,
+ IPIPE_TRACE_END,
+ IPIPE_TRACE_FREEZE,
+ IPIPE_TRACE_SPECIAL,
+};
+
+
+int ipipe_trace_enable = 1;
+
+static struct ipipe_trace_path trace_paths[NR_CPUS][IPIPE_TRACE_PATHS] =
+ { [0 ... NR_CPUS-1] =
+ { [0 ... IPIPE_TRACE_PATHS-1] =
+ { .begin = -1, .end = -1 }
+ }
+ };
+static int active_path[NR_CPUS] =
+ { [0 ... NR_CPUS-1] = IPIPE_DEFAULT_ACTIVE };
+static int max_path[NR_CPUS] =
+ { [0 ... NR_CPUS-1] = IPIPE_DEFAULT_MAX };
+static int frozen_path[NR_CPUS] =
+ { [0 ... NR_CPUS-1] = IPIPE_DEFAULT_FROZEN };
+static ipipe_spinlock_t global_path_lock = IPIPE_SPIN_LOCK_UNLOCKED;
+static int pre_trace = IPIPE_DEFAULT_PRE_TRACE;
+static int post_trace = IPIPE_DEFAULT_POST_TRACE;
+static int back_trace = IPIPE_DEFAULT_BACK_TRACE;
+static int verbose_trace = 0;
+
+static DECLARE_MUTEX(out_mutex);
+static struct ipipe_trace_path *print_path;
+static struct ipipe_trace_path *panic_path;
+static int print_pre_trace;
+static int print_post_trace;
+
+
+static long __ipipe_signed_tsc2us(long long tsc);
+static void
+__ipipe_trace_point_type(char *buf, struct ipipe_trace_point *point);
+static void __ipipe_print_symname(struct seq_file *m, unsigned long eip);
+
+
+static notrace int __ipipe_get_free_trace_path(int old, int cpu_id)
+{
+ int new_active = old;
+ struct ipipe_trace_path *tp;
+
+ do {
+ if (++new_active == IPIPE_TRACE_PATHS)
+ new_active = 0;
+ tp = &trace_paths[cpu_id][new_active];
+ } while ((new_active == max_path[cpu_id]) ||
+ (new_active == frozen_path[cpu_id]) ||
+ tp->dump_lock);
+
+ return new_active;
+}
+
+static notrace void
+__ipipe_migrate_pre_trace(struct ipipe_trace_path *new_tp,
+ struct ipipe_trace_path *old_tp, int old_pos)
+{
+ int i;
+
+ new_tp->trace_pos = pre_trace+1;
+
+ for (i = new_tp->trace_pos; i > 0; i--)
+ memcpy(&new_tp->point[WRAP_POINT_NO(new_tp->trace_pos-i)],
+ &old_tp->point[WRAP_POINT_NO(old_pos-i)],
+ sizeof(struct ipipe_trace_point));
+
+ /* mark the end (i.e. the point before point[0]) invalid */
+ new_tp->point[IPIPE_TRACE_POINTS-1].eip = 0;
+}
+
+static notrace struct ipipe_trace_path *
+__ipipe_trace_end(int cpu_id, struct ipipe_trace_path *tp, int pos)
+{
+ struct ipipe_trace_path *old_tp = tp;
+ long active = active_path[cpu_id];
+ unsigned long long length;
+
+ /* do we have a new worst case? */
+ length = tp->point[tp->end].timestamp -
+ tp->point[tp->begin].timestamp;
+ if (length > (trace_paths[cpu_id][max_path[cpu_id]]).length) {
+ /* we need protection here against other cpus trying
+ to start a proc dump */
+ spin_lock_hw(&global_path_lock);
+
+ /* active path holds new worst case */
+ tp->length = length;
+ max_path[cpu_id] = active;
+
+ /* find next unused trace path */
+ active = __ipipe_get_free_trace_path(active, cpu_id);
+
+ spin_unlock_hw(&global_path_lock);
+
+ tp = &trace_paths[cpu_id][active];
+
+ /* migrate last entries for pre-tracing */
+ __ipipe_migrate_pre_trace(tp, old_tp, pos);
+ }
+
+ return tp;
+}
+
+static notrace struct ipipe_trace_path *
+__ipipe_trace_freeze(int cpu_id, struct ipipe_trace_path *tp, int pos)
+{
+ struct ipipe_trace_path *old_tp = tp;
+ long active = active_path[cpu_id];
+ int i;
+
+ /* frozen paths have no core (begin=end) */
+ tp->begin = tp->end;
+
+ /* we need protection here against other cpus trying
+ * to set their frozen path or to start a proc dump */
+ spin_lock_hw(&global_path_lock);
+
+ frozen_path[cpu_id] = active;
+
+ /* find next unused trace path */
+ active = __ipipe_get_free_trace_path(active, cpu_id);
+
+ /* check if this is the first frozen path */
+ for_each_online_cpu(i) {
+ if ((i != cpu_id) &&
+ (trace_paths[i][frozen_path[i]].end >= 0))
+ tp->end = -1;
+ }
+
+ spin_unlock_hw(&global_path_lock);
+
+ tp = &trace_paths[cpu_id][active];
+
+ /* migrate last entries for pre-tracing */
+ __ipipe_migrate_pre_trace(tp, old_tp, pos);
+
+ return tp;
+}
+
+void notrace
+__ipipe_trace(enum ipipe_trace_type type, unsigned long eip,
+ unsigned long parent_eip, unsigned long v)
+{
+ struct ipipe_trace_path *tp, *old_tp;
+ int pos, next_pos, begin;
+ struct ipipe_trace_point *point;
+ unsigned long flags;
+ int cpu_id;
+
+ local_irq_save_hw_notrace(flags);
+
+ cpu_id = ipipe_processor_id();
+restart:
+ tp = old_tp = &trace_paths[cpu_id][active_path[cpu_id]];
+
+ /* here starts a race window with NMIs - catched below */
+
+ /* check for NMI recursion */
+ if (unlikely(tp->flags & IPIPE_TFLG_NMI_LOCK)) {
+ tp->flags |= IPIPE_TFLG_NMI_HIT;
+
+ /* first freeze request from NMI context? */
+ if ((type == IPIPE_TRACE_FREEZE) &&
+ !(tp->flags & IPIPE_TFLG_NMI_FREEZE_REQ)) {
+ /* save arguments and mark deferred freezing */
+ tp->flags |= IPIPE_TFLG_NMI_FREEZE_REQ;
+ tp->nmi_saved_eip = eip;
+ tp->nmi_saved_parent_eip = parent_eip;
+ tp->nmi_saved_v = v;
+ }
+ return; /* no need for restoring flags inside IRQ */
+ }
+
+ /* clear NMI events and set lock (atomically per cpu) */
+ tp->flags = (tp->flags & ~(IPIPE_TFLG_NMI_HIT |
+ IPIPE_TFLG_NMI_FREEZE_REQ))
+ | IPIPE_TFLG_NMI_LOCK;
+
+ /* check active_path again - some nasty NMI may have switched
+ * it meanwhile */
+ if (unlikely(tp != &trace_paths[cpu_id][active_path[cpu_id]])) {
+ /* release lock on wrong path and restart */
+ tp->flags &= ~IPIPE_TFLG_NMI_LOCK;
+
+ /* there is no chance that the NMI got deferred
+ * => no need to check for pending freeze requests */
+ goto restart;
+ }
+
+ /* get the point buffer */
+ pos = tp->trace_pos;
+ point = &tp->point[pos];
+
+ /* store all trace point data */
+ point->type = type;
+ point->flags = local_test_iflag_hw(flags) ? 0 : IPIPE_TFLG_HWIRQ_OFF;
+ point->eip = eip;
+ point->parent_eip = parent_eip;
+ point->v = v;
+ ipipe_read_tsc(point->timestamp);
+
+ /* forward to next point buffer */
+ next_pos = WRAP_POINT_NO(pos+1);
+ tp->trace_pos = next_pos;
+
+ /* only mark beginning if we haven't started yet */
+ begin = tp->begin;
+ if (unlikely(type == IPIPE_TRACE_BEGIN) && (begin < 0))
+ tp->begin = pos;
+
+ /* end of critical path, start post-trace if not already started */
+ if (unlikely(type == IPIPE_TRACE_END) &&
+ (begin >= 0) && !tp->post_trace)
+ tp->post_trace = post_trace + 1;
+
+ /* freeze only if the slot is free and we are not already freezing */
+ if (unlikely(type == IPIPE_TRACE_FREEZE) &&
+ (trace_paths[cpu_id][frozen_path[cpu_id]].begin < 0) &&
+ !(tp->flags & IPIPE_TFLG_FREEZING)) {
+ tp->post_trace = post_trace + 1;
+ tp->flags |= IPIPE_TFLG_FREEZING;
+ }
+
+ /* enforce end of trace in case of overflow */
+ if (unlikely(WRAP_POINT_NO(next_pos + 1) == begin)) {
+ tp->end = pos;
+ goto enforce_end;
+ }
+
+ /* stop tracing this path if we are in post-trace and
+ * a) that phase is over now or
+ * b) a new TRACE_BEGIN came in but we are not freezing this path */
+ if (unlikely((tp->post_trace > 0) && ((--tp->post_trace == 0) ||
+ ((type == IPIPE_TRACE_BEGIN) &&
+ !(tp->flags & IPIPE_TFLG_FREEZING))))) {
+ /* store the path's end (i.e. excluding post-trace) */
+ tp->end = WRAP_POINT_NO(pos - post_trace + tp->post_trace);
+
+enforce_end:
+ if (tp->flags & IPIPE_TFLG_FREEZING)
+ tp = __ipipe_trace_freeze(cpu_id, tp, pos);
+ else
+ tp = __ipipe_trace_end(cpu_id, tp, pos);
+
+ /* reset the active path, maybe already start a new one */
+ tp->begin = (type == IPIPE_TRACE_BEGIN) ?
+ WRAP_POINT_NO(tp->trace_pos - 1) : -1;
+ tp->end = -1;
+ tp->post_trace = 0;
+ tp->flags = 0;
+
+ /* update active_path not earlier to avoid races with NMIs */
+ active_path[cpu_id] = tp - trace_paths[cpu_id];
+ }
+
+ /* we still have old_tp and point,
+ * let's reset NMI lock and check for catches */
+ old_tp->flags &= ~IPIPE_TFLG_NMI_LOCK;
+ if (unlikely(old_tp->flags & IPIPE_TFLG_NMI_HIT)) {
+ /* well, this late tagging may not immediately be visible for
+ * other cpus already dumping this path - a minor issue */
+ point->flags |= IPIPE_TFLG_NMI_HIT;
+
+ /* handle deferred freezing from NMI context */
+ if (old_tp->flags & IPIPE_TFLG_NMI_FREEZE_REQ)
+ __ipipe_trace(IPIPE_TRACE_FREEZE, old_tp->nmi_saved_eip,
+ old_tp->nmi_saved_parent_eip,
+ old_tp->nmi_saved_v);
+ }
+
+ local_irq_restore_hw_notrace(flags);
+}
+
+static unsigned long __ipipe_global_path_lock(void)
+{
+ unsigned long flags;
+ int cpu_id;
+ struct ipipe_trace_path *tp;
+
+ spin_lock_irqsave_hw(&global_path_lock, flags);
+
+ cpu_id = ipipe_processor_id();
+restart:
+ tp = &trace_paths[cpu_id][active_path[cpu_id]];
+
+ /* here is small race window with NMIs - catched below */
+
+ /* clear NMI events and set lock (atomically per cpu) */
+ tp->flags = (tp->flags & ~(IPIPE_TFLG_NMI_HIT |
+ IPIPE_TFLG_NMI_FREEZE_REQ))
+ | IPIPE_TFLG_NMI_LOCK;
+
+ /* check active_path again - some nasty NMI may have switched
+ * it meanwhile */
+ if (tp != &trace_paths[cpu_id][active_path[cpu_id]]) {
+ /* release lock on wrong path and restart */
+ tp->flags &= ~IPIPE_TFLG_NMI_LOCK;
+
+ /* there is no chance that the NMI got deferred
+ * => no need to check for pending freeze requests */
+ goto restart;
+ }
+
+ return flags;
+}
+
+static void __ipipe_global_path_unlock(unsigned long flags)
+{
+ int cpu_id;
+ struct ipipe_trace_path *tp;
+
+ /* release spinlock first - it's not involved in the NMI issue */
+ spin_unlock_hw(&global_path_lock);
+
+ cpu_id = ipipe_processor_id();
+ tp = &trace_paths[cpu_id][active_path[cpu_id]];
+
+ tp->flags &= ~IPIPE_TFLG_NMI_LOCK;
+
+ /* handle deferred freezing from NMI context */
+ if (tp->flags & IPIPE_TFLG_NMI_FREEZE_REQ)
+ __ipipe_trace(IPIPE_TRACE_FREEZE, tp->nmi_saved_eip,
+ tp->nmi_saved_parent_eip, tp->nmi_saved_v);
+
+ local_irq_restore_hw(flags);
+}
+
+void notrace mcount(void);
+EXPORT_SYMBOL(mcount);
+
+void notrace ipipe_trace_begin(unsigned long v)
+{
+ if (!ipipe_trace_enable)
+ return;
+ __ipipe_trace(IPIPE_TRACE_BEGIN, __BUILTIN_RETURN_ADDRESS0,
+ __BUILTIN_RETURN_ADDRESS1, v);
+}
+EXPORT_SYMBOL(ipipe_trace_begin);
+
+void notrace ipipe_trace_end(unsigned long v)
+{
+ if (!ipipe_trace_enable)
+ return;
+ __ipipe_trace(IPIPE_TRACE_END, __BUILTIN_RETURN_ADDRESS0,
+ __BUILTIN_RETURN_ADDRESS1, v);
+}
+EXPORT_SYMBOL(ipipe_trace_end);
+
+void notrace ipipe_trace_freeze(unsigned long v)
+{
+ if (!ipipe_trace_enable)
+ return;
+ __ipipe_trace(IPIPE_TRACE_FREEZE, __BUILTIN_RETURN_ADDRESS0,
+ __BUILTIN_RETURN_ADDRESS1, v);
+}
+EXPORT_SYMBOL(ipipe_trace_freeze);
+
+void notrace ipipe_trace_special(unsigned char id, unsigned long v)
+{
+ if (!ipipe_trace_enable)
+ return;
+ __ipipe_trace(IPIPE_TRACE_SPECIAL + id, __BUILTIN_RETURN_ADDRESS0,
+ __BUILTIN_RETURN_ADDRESS1, v);
+}
+EXPORT_SYMBOL(ipipe_trace_special);
+
+int ipipe_trace_max_reset(void)
+{
+ int cpu_id;
+ unsigned long flags;
+ struct ipipe_trace_path *path;
+ int ret = 0;
+
+ flags = __ipipe_global_path_lock();
+
+ for_each_cpu(cpu_id) {
+ path = &trace_paths[cpu_id][max_path[cpu_id]];
+
+ if (path->dump_lock) {
+ ret = -EBUSY;
+ break;
+ }
+
+ path->begin = -1;
+ path->end = -1;
+ path->trace_pos = 0;
+ path->length = 0;
+ }
+
+ __ipipe_global_path_unlock(flags);
+
+ return ret;
+}
+EXPORT_SYMBOL(ipipe_trace_max_reset);
+
+int ipipe_trace_frozen_reset(void)
+{
+ int cpu_id;
+ unsigned long flags;
+ struct ipipe_trace_path *path;
+ int ret = 0;
+
+ flags = __ipipe_global_path_lock();
+
+ for_each_cpu(cpu_id) {
+ path = &trace_paths[cpu_id][frozen_path[cpu_id]];
+
+ if (path->dump_lock) {
+ ret = -EBUSY;
+ break;
+ }
+
+ path->begin = -1;
+ path->end = -1;
+ path->trace_pos = 0;
+ path->length = 0;
+ }
+
+ __ipipe_global_path_unlock(flags);
+
+ return ret;
+}
+EXPORT_SYMBOL(ipipe_trace_frozen_reset);
+
+void ipipe_trace_panic_freeze(void)
+{
+ unsigned long flags;
+ int cpu_id;
+
+ ipipe_trace_enable = 0;
+ local_irq_save_hw_notrace(flags);
+
+ cpu_id = ipipe_processor_id();
+
+ panic_path = &trace_paths[cpu_id][active_path[cpu_id]];
+
+ local_irq_restore_hw(flags);
+}
+EXPORT_SYMBOL(ipipe_trace_panic_freeze);
+
+void ipipe_trace_panic_dump(void)
+{
+ int cnt = back_trace;
+ int start, pos;
+
+ printk("I-pipe tracer log (%d points):\n", cnt);
+
+ start = pos = WRAP_POINT_NO(panic_path->trace_pos-1);
+
+ while (cnt-- > 0) {
+ struct ipipe_trace_point *point = &panic_path->point[pos];
+ long time;
+ char buf[16];
+
+ if (!point->eip)
+ printk("-<invalid>-\n");
+ else {
+ __ipipe_trace_point_type(buf, point);
+ printk(buf);
+
+ if (point->type != IPIPE_TRACE_FN)
+ printk("0x%08lx ", point->v);
+ else
+ printk(" ");
+
+ time = __ipipe_signed_tsc2us(point->timestamp -
+ panic_path->point[start].timestamp);
+ printk(" %5ld ", time);
+
+ __ipipe_print_symname(NULL, point->eip);
+ printk(" (");
+ __ipipe_print_symname(NULL, point->parent_eip);
+ printk(")\n");
+ }
+ pos = WRAP_POINT_NO(pos - 1);
+ }
+}
+EXPORT_SYMBOL(ipipe_trace_panic_dump);
+
+
+/* --- /proc output --- */
+
+static notrace int __ipipe_in_critical_trpath(long point_no)
+{
+ return ((WRAP_POINT_NO(point_no-print_path->begin) <
+ WRAP_POINT_NO(print_path->end-print_path->begin)) ||
+ ((print_path->end == print_path->begin) &&
+ (WRAP_POINT_NO(point_no-print_path->end) >
+ print_post_trace)));
+}
+
+static long __ipipe_signed_tsc2us(long long tsc)
+{
+ unsigned long long abs_tsc;
+ long us;
+
+ /* ipipe_tsc2us works on unsigned => handle sign separately */
+ abs_tsc = (tsc >= 0) ? tsc : -tsc;
+ us = ipipe_tsc2us(abs_tsc);
+ if (tsc < 0)
+ return -us;
+ else
+ return us;
+}
+
+static void
+__ipipe_trace_point_type(char *buf, struct ipipe_trace_point *point)
+{
+ switch (point->type) {
+ case IPIPE_TRACE_FN:
+ strcpy(buf, "fn ");
+ break;
+
+ case IPIPE_TRACE_BEGIN:
+ strcpy(buf, "begin ");
+ break;
+
+ case IPIPE_TRACE_END:
+ strcpy(buf, "end ");
+ break;
+
+ case IPIPE_TRACE_FREEZE:
+ strcpy(buf, "freeze ");
+ break;
+
+ default: /* IPIPE_TRACE_SPECIAL */
+ sprintf(buf, "(0x%02x) ",
+ point->type - IPIPE_TRACE_SPECIAL);
+ }
+}
+
+static void
+__ipipe_print_pathmark(struct seq_file *m, struct ipipe_trace_point *point)
+{
+ char mark = ' ';
+ int point_no = point - print_path->point;
+
+ if (print_path->end == point_no)
+ mark = '<';
+ else if (print_path->begin == point_no)
+ mark = '>';
+ else if (__ipipe_in_critical_trpath(point_no))
+ mark = ':';
+ seq_printf(m, "%c%c", mark,
+ (point->flags & IPIPE_TFLG_HWIRQ_OFF) ? '|' : ' ');
+}
+
+static void
+__ipipe_print_delay(struct seq_file *m, struct ipipe_trace_point *point)
+{
+ unsigned long delay = 0;
+ int next;
+ char *mark = " ";
+
+ next = WRAP_POINT_NO(point+1 - print_path->point);
+
+ if (next != print_path->trace_pos)
+ delay = ipipe_tsc2ns(print_path->point[next].timestamp -
+ point->timestamp);
+
+ if (__ipipe_in_critical_trpath(point - print_path->point)) {
+ if (delay > IPIPE_DELAY_WARN)
+ mark = "! ";
+ else if (delay > IPIPE_DELAY_NOTE)
+ mark = "+ ";
+ }
+ seq_puts(m, mark);
+
+ if (verbose_trace)
+ seq_printf(m, "%3lu.%03lu%c ", delay/1000, delay%1000,
+ (point->flags & IPIPE_TFLG_NMI_HIT) ? 'N' : ' ');
+ else
+ seq_puts(m, " ");
+}
+
+static void __ipipe_print_symname(struct seq_file *m, unsigned long eip)
+{
+ char namebuf[KSYM_NAME_LEN+1];
+ unsigned long size, offset;
+ const char *sym_name;
+ char *modname;
+
+ sym_name = kallsyms_lookup(eip, &size, &offset, &modname, namebuf);
+
+ /* printing to /proc? */
+ if (m) {
+ if (sym_name) {
+ if (verbose_trace) {
+ seq_printf(m, "%s+0x%lx", sym_name, offset);
+ if (modname)
+ seq_printf(m, " [%s]", modname);
+ } else
+ seq_puts(m, sym_name);
+ } else
+ seq_printf(m, "<%08lx>", eip);
+ } else {
+ /* panic dump */
+ if (sym_name) {
+ printk("%s+0x%lx", sym_name, offset);
+ if (modname)
+ printk(" [%s]", modname);
+ }
+ }
+}
+
+#if defined(CONFIG_XENO_OPT_DEBUG) || defined(CONFIG_DEBUG_PREEMPT)
+static void __ipipe_print_dbgwarning(struct seq_file *m)
+{
+ seq_puts(m, "\n******** WARNING ********\n"
+ "The following debugging options will increase the observed "
+ "latencies:\n"
+#ifdef CONFIG_XENO_OPT_DEBUG
+ " o CONFIG_XENO_OPT_DEBUG\n"
+#endif /* CONFIG_XENO_OPT_DEBUG */
+#ifdef CONFIG_DEBUG_PREEMPT
+ " o CONFIG_DEBUG_PREEMPT\n"
+#endif /* CONFIG_DEBUG_PREEMPT */
+ "\n");
+}
+#else /* !WARN_ON_DEBUGGING_LATENCIES */
+# define __ipipe_print_dbgwarning(m)
+#endif /* WARN_ON_DEBUGGING_LATENCIES */
+
+static void __ipipe_print_headline(struct seq_file *m)
+{
+ seq_puts(m, verbose_trace ?
+ " Type User Val. Time Delay Function (Parent)\n" :
+ " Type Time Function (Parent)\n");
+}
+
+static void *__ipipe_max_prtrace_start(struct seq_file *m, loff_t *pos)
+{
+ loff_t n = *pos;
+
+ down(&out_mutex);
+
+ if (!n) {
+ struct ipipe_trace_path *path;
+ unsigned long length_usecs;
+ int points, i;
+ unsigned long flags;
+
+ /* protect against max_path/frozen_path updates while we
+ * haven't locked our target path, also avoid recursively
+ * taking global_path_lock from NMI context */
+ flags = __ipipe_global_path_lock();
+
+ /* find the longest of all per-cpu paths */
+ print_path = NULL;
+ for_each_online_cpu(i) {
+ path = &trace_paths[i][max_path[i]];
+ if ((print_path == NULL) ||
+ (path->length > print_path->length))
+ print_path = path;
+ }
+ print_path->dump_lock = 1;
+
+ __ipipe_global_path_unlock(flags);
+
+ /* does this path actually contain data? */
+ if (print_path->end == print_path->begin)
+ return NULL;
+
+ /* number of points inside the critical path */
+ points = WRAP_POINT_NO(print_path->end-print_path->begin+1);
+
+ /* pre- and post-tracing length, post-trace length was frozen
+ in __ipipe_trace, pre-trace may have to be reduced due to
+ buffer overrun */
+ print_pre_trace = pre_trace;
+ print_post_trace = WRAP_POINT_NO(print_path->trace_pos -
+ print_path->end - 1);
+ if (points+pre_trace+print_post_trace > IPIPE_TRACE_POINTS - 1)
+ print_pre_trace = IPIPE_TRACE_POINTS - 1 - points -
+ print_post_trace;
+
+ length_usecs = ipipe_tsc2us(print_path->length);
+ seq_printf(m, "I-pipe worst-case tracing service on
%s/ipipe-%s\n"
+
"------------------------------------------------------------\n",
+ UTS_RELEASE, IPIPE_ARCH_STRING);
+ __ipipe_print_dbgwarning(m);
+ seq_printf(m, "Begin: %lld cycles, Trace Points: %d (-%d/+%d), "
+ "Length: %lu us\n\n",
+ print_path->point[print_path->begin].timestamp,
+ points, print_pre_trace, print_post_trace,
length_usecs);
+ __ipipe_print_headline(m);
+ }
+
+ /* check if we are inside the trace range */
+ if (n >= WRAP_POINT_NO(print_path->end - print_path->begin + 1 +
+ print_pre_trace + print_post_trace))
+ return NULL;
+
+ /* return the next point to be shown */
+ return &print_path->point[WRAP_POINT_NO(print_path->begin -
+ print_pre_trace + n)];
+}
+
+static void *__ipipe_prtrace_next(struct seq_file *m, void *p, loff_t *pos)
+{
+ loff_t n = ++*pos;
+
+ /* check if we are inside the trace range with the next entry */
+ if (n >= WRAP_POINT_NO(print_path->end - print_path->begin + 1 +
+ print_pre_trace + print_post_trace))
+ return NULL;
+
+ /* return the next point to be shown */
+ return &print_path->point[WRAP_POINT_NO(print_path->begin -
+ print_pre_trace + *pos)];
+}
+
+static void __ipipe_prtrace_stop(struct seq_file *m, void *p)
+{
+ if (print_path)
+ print_path->dump_lock = 0;
+ up(&out_mutex);
+}
+
+static int __ipipe_prtrace_show(struct seq_file *m, void *p)
+{
+ long time;
+ struct ipipe_trace_point *point = p;
+ char buf[16];
+
+ if (!point->eip) {
+ seq_puts(m, "-<invalid>-\n");
+ return 0;
+ }
+
+ __ipipe_print_pathmark(m, point);
+ __ipipe_trace_point_type(buf, point);
+ seq_puts(m, buf);
+ if (verbose_trace) {
+ if (point->type != IPIPE_TRACE_FN)
+ seq_printf(m, "0x%08lx ", point->v);
+ else
+ seq_puts(m, " ");
+ }
+
+ time = __ipipe_signed_tsc2us(point->timestamp -
+ print_path->point[print_path->begin].timestamp);
+ seq_printf(m, "%5ld", time);
+
+ __ipipe_print_delay(m, point);
+ __ipipe_print_symname(m, point->eip);
+ seq_puts(m, " (");
+ __ipipe_print_symname(m, point->parent_eip);
+ seq_puts(m, ")\n");
+
+ return 0;
+}
+
+static struct seq_operations __ipipe_max_ptrace_ops = {
+ .start = __ipipe_max_prtrace_start,
+ .next = __ipipe_prtrace_next,
+ .stop = __ipipe_prtrace_stop,
+ .show = __ipipe_prtrace_show
+};
+
+static int __ipipe_max_prtrace_open(struct inode *inode, struct file *file)
+{
+ return seq_open(file, &__ipipe_max_ptrace_ops);
+}
+
+static ssize_t
+__ipipe_max_reset(struct file *file, const char __user *pbuffer,
+ size_t count, loff_t *data)
+{
+ down(&out_mutex);
+ ipipe_trace_max_reset();
+ up(&out_mutex);
+
+ return count;
+}
+
+struct file_operations __ipipe_max_prtrace_fops = {
+ .open = __ipipe_max_prtrace_open,
+ .read = seq_read,
+ .write = __ipipe_max_reset,
+ .llseek = seq_lseek,
+ .release = seq_release,
+};
+
+static void *__ipipe_frozen_prtrace_start(struct seq_file *m, loff_t *pos)
+{
+ loff_t n = *pos;
+
+ down(&out_mutex);
+
+ if (!n) {
+ struct ipipe_trace_path *path;
+ int i;
+ unsigned long flags;
+
+ /* protect against max_path/frozen_path updates while we
+ * haven't locked our target path, also avoid recursively
+ * taking global_path_lock from NMI context */
+ flags = __ipipe_global_path_lock();
+
+ /* find the first of all per-cpu frozen paths */
+ print_path = NULL;
+ for_each_online_cpu(i) {
+ path = &trace_paths[i][frozen_path[i]];
+ if (path->end >= 0)
+ print_path = path;
+ }
+ if (print_path)
+ print_path->dump_lock = 1;
+
+ __ipipe_global_path_unlock(flags);
+
+ if (!print_path)
+ return NULL;
+
+ /* back- and post-tracing length, post-trace length was frozen
+ in __ipipe_trace, back-trace may have to be reduced due to
+ buffer overrun */
+ print_pre_trace = back_trace-1; /* substract freeze point */
+ print_post_trace = WRAP_POINT_NO(print_path->trace_pos -
+ print_path->end - 1);
+ if (1+pre_trace+print_post_trace > IPIPE_TRACE_POINTS - 1)
+ print_pre_trace = IPIPE_TRACE_POINTS - 2 -
+ print_post_trace;
+
+ seq_printf(m, "I-pipe frozen back-tracing service on
%s/ipipe-%s\n"
+ "------------------------------------------------------"
+ "------\n",
+ UTS_RELEASE, IPIPE_ARCH_STRING);
+ __ipipe_print_dbgwarning(m);
+ seq_printf(m, "Freeze: %lld cycles, Trace Points: %d (+%d)\n\n",
+ print_path->point[print_path->begin].timestamp,
+ print_pre_trace+1, print_post_trace);
+
+ seq_puts(m, verbose_trace ?
+ " Type User Val. Time Delay Function
(Parent)\n" :
+ " Type Time Function (Parent)\n");
+ }
+
+ /* check if we are inside the trace range */
+ if (n >= print_pre_trace + 1 + print_post_trace)
+ return NULL;
+
+ /* return the next point to be shown */
+ return &print_path->point[WRAP_POINT_NO(print_path->begin-
+ print_pre_trace+n)];
+}
+
+static struct seq_operations __ipipe_frozen_ptrace_ops = {
+ .start = __ipipe_frozen_prtrace_start,
+ .next = __ipipe_prtrace_next,
+ .stop = __ipipe_prtrace_stop,
+ .show = __ipipe_prtrace_show
+};
+
+static int __ipipe_frozen_prtrace_open(struct inode *inode, struct file *file)
+{
+ return seq_open(file, &__ipipe_frozen_ptrace_ops);
+}
+
+static ssize_t
+__ipipe_frozen_reset(struct file *file, const char __user *pbuffer,
+ size_t count, loff_t *data)
+{
+ down(&out_mutex);
+ ipipe_trace_frozen_reset();
+ up(&out_mutex);
+
+ return count;
+}
+
+struct file_operations __ipipe_frozen_prtrace_fops = {
+ .open = __ipipe_frozen_prtrace_open,
+ .read = seq_read,
+ .write = __ipipe_frozen_reset,
+ .llseek = seq_lseek,
+ .release = seq_release,
+};
+
+static int __ipipe_rd_proc_val(char *page, char **start, off_t off,
+ int count, int *eof, void *data)
+{
+ int len;
+
+ len = sprintf(page, "%u\n", *(int *)data);
+ len -= off;
+ if (len <= off + count)
+ *eof = 1;
+ *start = page + off;
+ if (len > count)
+ len = count;
+ if (len < 0)
+ len = 0;
+
+ return len;
+}
+
+static int __ipipe_wr_proc_val(struct file *file, const char __user *buffer,
+ unsigned long count, void *data)
+{
+ char *end, buf[16];
+ int val;
+ int n;
+
+ n = (count > sizeof(buf) - 1) ? sizeof(buf) - 1 : count;
+
+ if (copy_from_user(buf, buffer, n))
+ return -EFAULT;
+
+ buf[n] = '\0';
+ val = simple_strtol(buf, &end, 0);
+
+ if (((*end != '\0') && !isspace(*end)) || (val < 0))
+ return -EINVAL;
+
+ down(&out_mutex);
+ *(int *)data = val;
+ up(&out_mutex);
+
+ return count;
+}
+
+extern struct proc_dir_entry *ipipe_proc_root;
+
+static void __init
+__ipipe_create_trace_proc_val(struct proc_dir_entry *trace_dir,
+ const char *name, int *value_ptr)
+{
+ struct proc_dir_entry *entry;
+
+ entry = create_proc_entry(name, 0644, trace_dir);
+ if (entry) {
+ entry->data = value_ptr;
+ entry->read_proc = __ipipe_rd_proc_val;
+ entry->write_proc = __ipipe_wr_proc_val;
+ entry->owner = THIS_MODULE;
+ }
+}
+
+void __init __ipipe_init_trace_proc(void)
+{
+ struct proc_dir_entry *trace_dir;
+ struct proc_dir_entry *entry;
+
+ trace_dir = create_proc_entry("trace", S_IFDIR, ipipe_proc_root);
+
+ entry = create_proc_entry("max", 0644, trace_dir);
+ if (entry)
+ entry->proc_fops = &__ipipe_max_prtrace_fops;
+
+ entry = create_proc_entry("frozen", 0644, trace_dir);
+ if (entry)
+ entry->proc_fops = &__ipipe_frozen_prtrace_fops;
+
+ __ipipe_create_trace_proc_val(trace_dir, "pre_trace_points",
+ &pre_trace);
+ __ipipe_create_trace_proc_val(trace_dir, "post_trace_points",
+ &post_trace);
+ __ipipe_create_trace_proc_val(trace_dir, "back_trace_points",
+ &back_trace);
+ __ipipe_create_trace_proc_val(trace_dir, "verbose",
+ &verbose_trace);
+ __ipipe_create_trace_proc_val(trace_dir, "enable",
+ &ipipe_trace_enable);
+}
--- 2.6.16/arch/i386/boot/compressed/misc.c 2006-03-20 06:53:29.000000000
+0100
+++ 2.6.16-ipipe/arch/i386/boot/compressed/misc.c 2006-03-21
14:52:55.000000000 +0100
@@ -15,6 +15,12 @@
#include <asm/io.h>
#include <asm/page.h>
+#ifdef CONFIG_IPIPE_TRACE
+void __attribute__ ((no_instrument_function)) mcount(void)
+{
+}
+#endif
+
/*
* gzip declarations
*/
@@ -112,7 +118,7 @@ static long free_mem_end_ptr;
#define INPLACE_MOVE_ROUTINE 0x1000
#define LOW_BUFFER_START 0x2000
#define LOW_BUFFER_MAX 0x90000
-#define HEAP_SIZE 0x3000
+#define HEAP_SIZE 0x4000
static unsigned int low_buffer_end, low_buffer_size;
static int high_loaded =0;
static uch *high_buffer_start /* = (uch *)(((ulg)&end) + HEAP_SIZE)*/;
--- 2.6.16/arch/i386/kernel/ipipe-mcount.S 1970-01-01 01:00:00.000000000
+0100
+++ 2.6.16-ipipe/arch/i386/kernel/ipipe-mcount.S 2005-12-29
14:04:04.000000000 +0100
@@ -0,0 +1,45 @@
+/*
+ * linux/arch/i386/ipipe-mcount.S
+ *
+ * Copyright (C) 2005 Jan Kiszka
+ */
+
+#include <linux/config.h>
+
+.globl mcount
+mcount:
+ cmpl $0,ipipe_trace_enable
+ je out
+
+ pushl %ebp
+ movl %esp,%ebp
+
+ pushl %eax
+ pushl %ecx
+ pushl %edx
+
+ pushl $0 # no additional value (v)
+#ifdef CONFIG_REGPARM
+ movl (%ebp),%eax
+ movl 0x4(%ebp),%edx # __CALLER_ADDR0
+ movl 0x4(%eax),%ecx # __CALLER_ADDR1
+ movl $0,%eax # IPIPE_TRACE_FN
+ call __ipipe_trace
+ popl %eax
+#else /* !CONFIG_REGPARM */
+ movl (%ebp),%eax
+ movl 0x4(%eax),%eax
+ pushl %eax # __CALLER_ADDR1
+ movl 0x4(%ebp),%eax
+ pushl %eax # __CALLER_ADDR0
+ pushl $0 # IPIPE_TRACE_FN
+ call __ipipe_trace
+ addl $0x10,%esp
+#endif /* CONFIG_REGPARM */
+
+ popl %edx
+ popl %ecx
+ popl %eax
+ popl %ebp
+out:
+ ret
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