[patch 3/3] x86, bts, ftrace: adapt the hw-branch-tracer to the ds.c interface
From: Markus Metzger
Date: Thu Dec 11 2008 - 07:53:47 EST
Remove BTS bits from the hw-branch-tracer (renamed from bts-tracer) and use the ds interface.
Signed-off-by: Markus Metzger <markut.t.metzger@xxxxxxxxx>
---
Index: gits/kernel/trace/trace_bts.c
===================================================================
--- gits.orig/kernel/trace/trace_bts.c 2008-12-11 10:45:12.000000000 +0100
+++ /dev/null 1970-01-01 00:00:00.000000000 +0000
@@ -1,276 +0,0 @@
-/*
- * BTS tracer
- *
- * Copyright (C) 2008 Markus Metzger <markus.t.metzger@xxxxxxxxx>
- *
- */
-
-#include <linux/module.h>
-#include <linux/fs.h>
-#include <linux/debugfs.h>
-#include <linux/ftrace.h>
-#include <linux/kallsyms.h>
-
-#include <asm/ds.h>
-
-#include "trace.h"
-
-
-#define SIZEOF_BTS (1 << 13)
-
-static DEFINE_PER_CPU(struct bts_tracer *, tracer);
-static DEFINE_PER_CPU(unsigned char[SIZEOF_BTS], buffer);
-
-#define this_tracer per_cpu(tracer, smp_processor_id())
-#define this_buffer per_cpu(buffer, smp_processor_id())
-
-
-/*
- * Information to interpret a BTS record.
- * This will go into an in-kernel BTS interface.
- */
-static unsigned char sizeof_field;
-static unsigned long debugctl_mask;
-
-#define sizeof_bts (3 * sizeof_field)
-
-static void bts_trace_cpuinit(struct cpuinfo_x86 *c)
-{
- switch (c->x86) {
- case 0x6:
- switch (c->x86_model) {
- case 0x0 ... 0xC:
- break;
- case 0xD:
- case 0xE: /* Pentium M */
- sizeof_field = sizeof(long);
- debugctl_mask = (1<<6)|(1<<7);
- break;
- default:
- sizeof_field = 8;
- debugctl_mask = (1<<6)|(1<<7);
- break;
- }
- break;
- case 0xF:
- switch (c->x86_model) {
- case 0x0:
- case 0x1:
- case 0x2: /* Netburst */
- sizeof_field = sizeof(long);
- debugctl_mask = (1<<2)|(1<<3);
- break;
- default:
- /* sorry, don't know about them */
- break;
- }
- break;
- default:
- /* sorry, don't know about them */
- break;
- }
-}
-
-static inline void bts_enable(void)
-{
- unsigned long debugctl;
-
- rdmsrl(MSR_IA32_DEBUGCTLMSR, debugctl);
- wrmsrl(MSR_IA32_DEBUGCTLMSR, debugctl | debugctl_mask);
-}
-
-static inline void bts_disable(void)
-{
- unsigned long debugctl;
-
- rdmsrl(MSR_IA32_DEBUGCTLMSR, debugctl);
- wrmsrl(MSR_IA32_DEBUGCTLMSR, debugctl & ~debugctl_mask);
-}
-
-static void bts_trace_reset(struct trace_array *tr)
-{
- int cpu;
-
- tr->time_start = ftrace_now(tr->cpu);
-
- for_each_online_cpu(cpu)
- tracing_reset(tr, cpu);
-}
-
-static void bts_trace_start_cpu(void *arg)
-{
- this_tracer =
- ds_request_bts(/* task = */ NULL, this_buffer, SIZEOF_BTS,
- /* ovfl = */ NULL, /* th = */ (size_t)-1);
- if (IS_ERR(this_tracer)) {
- this_tracer = NULL;
- return;
- }
-
- bts_enable();
-}
-
-static void bts_trace_start(struct trace_array *tr)
-{
- int cpu;
-
- bts_trace_reset(tr);
-
- for_each_cpu_mask(cpu, cpu_possible_map)
- smp_call_function_single(cpu, bts_trace_start_cpu, NULL, 1);
-}
-
-static void bts_trace_stop_cpu(void *arg)
-{
- if (this_tracer) {
- bts_disable();
-
- ds_release_bts(this_tracer);
- this_tracer = NULL;
- }
-}
-
-static void bts_trace_stop(struct trace_array *tr)
-{
- int cpu;
-
- for_each_cpu_mask(cpu, cpu_possible_map)
- smp_call_function_single(cpu, bts_trace_stop_cpu, NULL, 1);
-}
-
-static int bts_trace_init(struct trace_array *tr)
-{
- bts_trace_cpuinit(&boot_cpu_data);
- bts_trace_reset(tr);
- bts_trace_start(tr);
-
- return 0;
-}
-
-static void bts_trace_print_header(struct seq_file *m)
-{
-#ifdef __i386__
- seq_puts(m, "# CPU# FROM TO FUNCTION\n");
- seq_puts(m, "# | | | |\n");
-#else
- seq_puts(m,
- "# CPU# FROM TO FUNCTION\n");
- seq_puts(m,
- "# | | | |\n");
-#endif
-}
-
-static enum print_line_t bts_trace_print_line(struct trace_iterator *iter)
-{
- struct trace_entry *entry = iter->ent;
- struct trace_seq *seq = &iter->seq;
- struct bts_entry *it;
-
- trace_assign_type(it, entry);
-
- if (entry->type == TRACE_BTS) {
- int ret;
-#ifdef CONFIG_KALLSYMS
- char function[KSYM_SYMBOL_LEN];
- sprint_symbol(function, it->from);
-#else
- char *function = "<unknown>";
-#endif
-
- ret = trace_seq_printf(seq, "%4d 0x%lx -> 0x%lx [%s]\n",
- entry->cpu, it->from, it->to, function);
- if (!ret)
- return TRACE_TYPE_PARTIAL_LINE;;
- return TRACE_TYPE_HANDLED;
- }
- return TRACE_TYPE_UNHANDLED;
-}
-
-void trace_bts(struct trace_array *tr, unsigned long from, unsigned long to)
-{
- struct ring_buffer_event *event;
- struct bts_entry *entry;
- unsigned long irq;
-
- event = ring_buffer_lock_reserve(tr->buffer, sizeof(*entry), &irq);
- if (!event)
- return;
- entry = ring_buffer_event_data(event);
- tracing_generic_entry_update(&entry->ent, 0, from);
- entry->ent.type = TRACE_BTS;
- entry->ent.cpu = smp_processor_id();
- entry->from = from;
- entry->to = to;
- ring_buffer_unlock_commit(tr->buffer, event, irq);
-}
-
-static void trace_bts_at(struct trace_array *tr, size_t index)
-{
- const void *raw = NULL;
- unsigned long from, to;
- int err;
-
- err = ds_access_bts(this_tracer, index, &raw);
- if (err < 0)
- return;
-
- from = *(const unsigned long *)raw;
- to = *(const unsigned long *)((const char *)raw + sizeof_field);
-
- trace_bts(tr, from, to);
-}
-
-static void trace_bts_cpu(void *arg)
-{
- struct trace_array *tr = (struct trace_array *) arg;
- size_t index = 0, end = 0, i;
- int err;
-
- if (!this_tracer)
- return;
-
- bts_disable();
-
- err = ds_get_bts_index(this_tracer, &index);
- if (err < 0)
- goto out;
-
- err = ds_get_bts_end(this_tracer, &end);
- if (err < 0)
- goto out;
-
- for (i = index; i < end; i++)
- trace_bts_at(tr, i);
-
- for (i = 0; i < index; i++)
- trace_bts_at(tr, i);
-
-out:
- bts_enable();
-}
-
-static void trace_bts_prepare(struct trace_iterator *iter)
-{
- int cpu;
-
- for_each_cpu_mask(cpu, cpu_possible_map)
- smp_call_function_single(cpu, trace_bts_cpu, iter->tr, 1);
-}
-
-struct tracer bts_tracer __read_mostly =
-{
- .name = "bts",
- .init = bts_trace_init,
- .reset = bts_trace_stop,
- .print_header = bts_trace_print_header,
- .print_line = bts_trace_print_line,
- .start = bts_trace_start,
- .stop = bts_trace_stop,
- .open = trace_bts_prepare
-};
-
-__init static int init_bts_trace(void)
-{
- return register_tracer(&bts_tracer);
-}
-device_initcall(init_bts_trace);
Index: gits/kernel/trace/trace_hw_branches.c
===================================================================
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ gits/kernel/trace/trace_hw_branches.c 2008-12-11 11:21:19.000000000 +0100
@@ -0,0 +1,205 @@
+/*
+ * h/w branch tracer for x86 based on bts
+ *
+ * Copyright (C) 2008 Markus Metzger <markus.t.metzger@xxxxxxxxx>
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/fs.h>
+#include <linux/debugfs.h>
+#include <linux/ftrace.h>
+#include <linux/kallsyms.h>
+
+#include <asm/ds.h>
+
+#include "trace.h"
+
+
+#define SIZEOF_BTS (1 << 13)
+
+static DEFINE_PER_CPU(struct bts_tracer *, tracer);
+static DEFINE_PER_CPU(unsigned char[SIZEOF_BTS], buffer);
+
+#define this_tracer per_cpu(tracer, smp_processor_id())
+#define this_buffer per_cpu(buffer, smp_processor_id())
+
+
+static void bts_trace_reset(struct trace_array *tr)
+{
+ int cpu;
+
+ tr->time_start = ftrace_now(tr->cpu);
+
+ for_each_online_cpu(cpu)
+ tracing_reset(tr, cpu);
+}
+
+static void bts_trace_start_cpu(void *arg)
+{
+ if (this_tracer)
+ ds_release_bts(this_tracer);
+
+ this_tracer =
+ ds_request_bts(/* task = */ NULL, this_buffer, SIZEOF_BTS,
+ /* ovfl = */ NULL, /* th = */ (size_t)-1,
+ BTS_KERNEL);
+ if (IS_ERR(this_tracer)) {
+ this_tracer = NULL;
+ return;
+ }
+}
+
+static void bts_trace_start(struct trace_array *tr)
+{
+ int cpu;
+
+ bts_trace_reset(tr);
+
+ for_each_cpu_mask(cpu, cpu_possible_map)
+ smp_call_function_single(cpu, bts_trace_start_cpu, NULL, 1);
+}
+
+static void bts_trace_stop_cpu(void *arg)
+{
+ if (this_tracer) {
+ ds_release_bts(this_tracer);
+ this_tracer = NULL;
+ }
+}
+
+static void bts_trace_stop(struct trace_array *tr)
+{
+ int cpu;
+
+ for_each_cpu_mask(cpu, cpu_possible_map)
+ smp_call_function_single(cpu, bts_trace_stop_cpu, NULL, 1);
+}
+
+static int bts_trace_init(struct trace_array *tr)
+{
+ bts_trace_reset(tr);
+ bts_trace_start(tr);
+
+ return 0;
+}
+
+static void bts_trace_print_header(struct seq_file *m)
+{
+ seq_puts(m,
+ "# CPU# FROM TO FUNCTION\n");
+ seq_puts(m,
+ "# | | | |\n");
+}
+
+static enum print_line_t bts_trace_print_line(struct trace_iterator *iter)
+{
+ struct trace_entry *entry = iter->ent;
+ struct trace_seq *seq = &iter->seq;
+ struct hw_branch_entry *it;
+
+ trace_assign_type(it, entry);
+
+ if (entry->type == TRACE_HW_BRANCHES) {
+ if (trace_seq_printf(seq, "%4d ", entry->cpu) &&
+ trace_seq_printf(seq, "0x%016llx -> 0x%016llx ",
+ it->from, it->to) &&
+ (!it->from ||
+ seq_print_ip_sym(seq, it->from, /* sym_flags = */ 0)) &&
+ trace_seq_printf(seq, "\n"))
+ return TRACE_TYPE_HANDLED;
+ return TRACE_TYPE_PARTIAL_LINE;;
+ }
+ return TRACE_TYPE_UNHANDLED;
+}
+
+void trace_hw_branch(struct trace_array *tr, u64 from, u64 to)
+{
+ struct ring_buffer_event *event;
+ struct hw_branch_entry *entry;
+ unsigned long irq;
+
+ event = ring_buffer_lock_reserve(tr->buffer, sizeof(*entry), &irq);
+ if (!event)
+ return;
+ entry = ring_buffer_event_data(event);
+ tracing_generic_entry_update(&entry->ent, 0, from);
+ entry->ent.type = TRACE_HW_BRANCHES;
+ entry->ent.cpu = smp_processor_id();
+ entry->from = from;
+ entry->to = to;
+ ring_buffer_unlock_commit(tr->buffer, event, irq);
+}
+
+static void trace_bts_at(struct trace_array *tr,
+ const struct bts_trace *trace, void *at)
+{
+ struct bts_struct bts;
+ int err = 0;
+
+ WARN_ON_ONCE(!trace->read);
+ if (!trace->read)
+ return;
+
+ err = trace->read(this_tracer, at, &bts);
+ if (err < 0)
+ return;
+
+ switch (bts.qualifier) {
+ case BTS_BRANCH:
+ trace_hw_branch(tr, bts.variant.lbr.from, bts.variant.lbr.to);
+ break;
+ }
+}
+
+static void trace_bts_cpu(void *arg)
+{
+ struct trace_array *tr = (struct trace_array *) arg;
+ const struct bts_trace *trace;
+ unsigned char *at;
+
+ if (!this_tracer)
+ return;
+
+ ds_suspend_bts(this_tracer);
+ trace = ds_read_bts(this_tracer);
+ if (!trace)
+ goto out;
+
+ for (at = trace->ds.top; (void *)at < trace->ds.end;
+ at += trace->ds.size)
+ trace_bts_at(tr, trace, at);
+
+ for (at = trace->ds.begin; (void *)at < trace->ds.top;
+ at += trace->ds.size)
+ trace_bts_at(tr, trace, at);
+
+out:
+ ds_resume_bts(this_tracer);
+}
+
+static void trace_bts_prepare(struct trace_iterator *iter)
+{
+ int cpu;
+
+ for_each_cpu_mask(cpu, cpu_possible_map)
+ smp_call_function_single(cpu, trace_bts_cpu, iter->tr, 1);
+}
+
+struct tracer bts_tracer __read_mostly =
+{
+ .name = "hw-branch-tracer",
+ .init = bts_trace_init,
+ .reset = bts_trace_stop,
+ .print_header = bts_trace_print_header,
+ .print_line = bts_trace_print_line,
+ .start = bts_trace_start,
+ .stop = bts_trace_stop,
+ .open = trace_bts_prepare
+};
+
+__init static int init_bts_trace(void)
+{
+ return register_tracer(&bts_tracer);
+}
+device_initcall(init_bts_trace);
Index: gits/kernel/trace/trace.h
===================================================================
--- gits.orig/kernel/trace/trace.h 2008-12-11 10:45:12.000000000 +0100
+++ gits/kernel/trace/trace.h 2008-12-11 11:21:57.000000000 +0100
@@ -28,7 +28,7 @@
TRACE_GRAPH_RET,
TRACE_GRAPH_ENT,
TRACE_USER_STACK,
- TRACE_BTS,
+ TRACE_HW_BRANCHES,
TRACE_POWER,
__TRACE_LAST_TYPE
@@ -159,10 +159,10 @@
char correct;
};
-struct bts_entry {
+struct hw_branch_entry {
struct trace_entry ent;
- unsigned long from;
- unsigned long to;
+ u64 from;
+ u64 to;
};
struct trace_power {
@@ -278,7 +278,7 @@
TRACE_GRAPH_ENT); \
IF_ASSIGN(var, ent, struct ftrace_graph_ret_entry, \
TRACE_GRAPH_RET); \
- IF_ASSIGN(var, ent, struct bts_entry, TRACE_BTS);\
+ IF_ASSIGN(var, ent, struct hw_branch_entry, TRACE_HW_BRANCHES);\
IF_ASSIGN(var, ent, struct trace_power, TRACE_POWER); \
__ftrace_bad_type(); \
} while (0)
@@ -414,9 +414,7 @@
void trace_graph_return(struct ftrace_graph_ret *trace);
int trace_graph_entry(struct ftrace_graph_ent *trace);
-void trace_bts(struct trace_array *tr,
- unsigned long from,
- unsigned long to);
+void trace_hw_branch(struct trace_array *tr, u64 from, u64 to);
void tracing_start_cmdline_record(void);
void tracing_stop_cmdline_record(void);
Index: gits/kernel/trace/Kconfig
===================================================================
--- gits.orig/kernel/trace/Kconfig 2008-12-11 10:45:12.000000000 +0100
+++ gits/kernel/trace/Kconfig 2008-12-11 11:21:19.000000000 +0100
@@ -251,9 +251,9 @@
Say N if unsure.
-config BTS_TRACER
+config HW_BRANCH_TRACER
depends on HAVE_HW_BRANCH_TRACER
- bool "Trace branches"
+ bool "Trace hw branches"
select TRACING
help
This tracer records all branches on the system in a circular
Index: gits/kernel/trace/Makefile
===================================================================
--- gits.orig/kernel/trace/Makefile 2008-12-11 10:45:12.000000000 +0100
+++ gits/kernel/trace/Makefile 2008-12-11 11:21:19.000000000 +0100
@@ -31,7 +31,7 @@
obj-$(CONFIG_BOOT_TRACER) += trace_boot.o
obj-$(CONFIG_FUNCTION_GRAPH_TRACER) += trace_functions_graph.o
obj-$(CONFIG_TRACE_BRANCH_PROFILING) += trace_branch.o
-obj-$(CONFIG_BTS_TRACER) += trace_bts.o
+obj-$(CONFIG_HW_BRANCH_TRACER) += trace_hw_branches.o
obj-$(CONFIG_POWER_TRACER) += trace_power.o
libftrace-y := ftrace.o
Index: gits/kernel/trace/trace.c
===================================================================
--- gits.orig/kernel/trace/trace.c 2008-12-11 10:45:12.000000000 +0100
+++ gits/kernel/trace/trace.c 2008-12-11 11:21:19.000000000 +0100
@@ -2425,7 +2425,7 @@
/* Notify the tracer early; before we stop tracing. */
if (iter->trace && iter->trace->open)
- iter->trace->open(iter);
+ iter->trace->open(iter);
/* Annotate start of buffers if we had overruns */
if (ring_buffer_overruns(iter->tr->buffer))
--
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