x86, bts, ftrace: adapt the hw-branch-tracer to the ds.c interface
authorMarkus Metzger <markut.t.metzger@intel.com>
Thu, 11 Dec 2008 12:53:26 +0000 (13:53 +0100)
committerIngo Molnar <mingo@elte.hu>
Fri, 12 Dec 2008 07:08:14 +0000 (08:08 +0100)
Impact: restructure code, cleanup

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@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
kernel/trace/Kconfig
kernel/trace/Makefile
kernel/trace/trace.c
kernel/trace/trace.h
kernel/trace/trace_bts.c [deleted file]
kernel/trace/trace_hw_branches.c [new file with mode: 0644]

index bde6f03512d50ea9322226f2c99c80fac77a22ad..d8bae6f4219ee32cc869fbaaee22a488553289e1 100644 (file)
@@ -251,9 +251,9 @@ config STACK_TRACER
 
          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 62dc561b6676ab57ced3b65f5804c0e50f31730a..349d5a93653f340d6b6727668cbc6e6a0436e072 100644 (file)
@@ -31,7 +31,7 @@ obj-$(CONFIG_MMIOTRACE) += trace_mmiotrace.o
 obj-$(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 8ebe0070c47ab77b61efbef9ef8b92419aa7b677..639344a4d3a2ddc1f4246fefbad9383e38e5f87f 100644 (file)
@@ -2425,7 +2425,7 @@ __tracing_open(struct inode *inode, struct file *file, int *ret)
 
        /* 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))
index 5ac697065a48cb7bd2c08adbdf98d6ea3c42d93e..f07c246dd73dab7b283048df72bce71b36b34f4d 100644 (file)
@@ -28,7 +28,7 @@ enum trace_type {
        TRACE_GRAPH_RET,
        TRACE_GRAPH_ENT,
        TRACE_USER_STACK,
-       TRACE_BTS,
+       TRACE_HW_BRANCHES,
        TRACE_POWER,
 
        __TRACE_LAST_TYPE
@@ -159,10 +159,10 @@ struct trace_branch {
        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 @@ extern void __ftrace_bad_type(void);
                          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_function(struct trace_array *tr,
 
 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);
diff --git a/kernel/trace/trace_bts.c b/kernel/trace/trace_bts.c
deleted file mode 100644 (file)
index 23b76e4..0000000
+++ /dev/null
@@ -1,276 +0,0 @@
-/*
- * BTS tracer
- *
- * Copyright (C) 2008 Markus Metzger <markus.t.metzger@gmail.com>
- *
- */
-
-#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);
diff --git a/kernel/trace/trace_hw_branches.c b/kernel/trace/trace_hw_branches.c
new file mode 100644 (file)
index 0000000..ee29e01
--- /dev/null
@@ -0,0 +1,205 @@
+/*
+ * h/w branch tracer for x86 based on bts
+ *
+ * Copyright (C) 2008 Markus Metzger <markus.t.metzger@gmail.com>
+ *
+ */
+
+#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);