Merge branch 'tip/tracing/ftrace' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace into tracing/ftrace

9 files changed, 48 insertions, 95 deletions

diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c
index e82cb9e930cc..e39679a72a3b 100644
--- a/kernel/trace/blktrace.c
+++ b/kernel/trace/blktrace.c
@@ -1231,7 +1231,6 @@ static struct tracer blk_tracer __read_mostly = {
 static struct trace_event trace_blk_event = {
         .type           = TRACE_BLK,
         .trace          = blk_trace_event_print,
-        .latency_trace  = blk_trace_event_print,
         .binary         = blk_trace_event_print_binary,
 };
 
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index f2a163db52f9..f7473645b9c6 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -2461,6 +2461,7 @@ int ring_buffer_read_page(struct ring_buffer *buffer,
         unsigned long flags;
         unsigned int commit;
         unsigned int read;
+        u64 save_timestamp;
         int ret = -1;
 
         /*
@@ -2515,6 +2516,9 @@ int ring_buffer_read_page(struct ring_buffer *buffer,
                 if (len < size)
                         goto out;
 
+                /* save the current timestamp, since the user will need it */
+                save_timestamp = cpu_buffer->read_stamp;
+
                 /* Need to copy one event at a time */
                 do {
                         memcpy(bpage->data + pos, rpage->data + rpos, size);
@@ -2531,7 +2535,7 @@ int ring_buffer_read_page(struct ring_buffer *buffer,
 
                 /* update bpage */
                 local_set(&bpage->commit, pos);
-                bpage->time_stamp = rpage->time_stamp;
+                bpage->time_stamp = save_timestamp;
 
                 /* we copied everything to the beginning */
                 read = 0;
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index c8abbb0c8397..d1ef43999d9e 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -299,6 +299,7 @@ static const char *trace_options[] = {
         "sym-userobj",
         "printk-msg-only",
         "context-info",
+        "latency-format",
         NULL
 };
 
@@ -346,6 +347,9 @@ ssize_t trace_seq_to_user(struct trace_seq *s, char __user *ubuf, size_t cnt)
         int len;
         int ret;
 
+        if (!cnt)
+                return 0;
+
         if (s->len <= s->readpos)
                 return -EBUSY;
 
@@ -353,10 +357,12 @@ ssize_t trace_seq_to_user(struct trace_seq *s, char __user *ubuf, size_t cnt)
         if (cnt > len)
                 cnt = len;
         ret = copy_to_user(ubuf, s->buffer + s->readpos, cnt);
-        if (ret)
+        if (ret == cnt)
                 return -EFAULT;
 
-        s->readpos += len;
+        cnt -= ret;
+
+        s->readpos += cnt;
         return cnt;
 }
 
@@ -375,7 +381,7 @@ ssize_t trace_seq_to_buffer(struct trace_seq *s, void *buf, size_t cnt)
         if (!ret)
                 return -EFAULT;
 
-        s->readpos += len;
+        s->readpos += cnt;
         return cnt;
 }
 
@@ -1462,33 +1468,6 @@ static void test_cpu_buff_start(struct trace_iterator *iter)
         trace_seq_printf(s, "##### CPU %u buffer started ####\n", iter->cpu);
 }
 
-static enum print_line_t print_lat_fmt(struct trace_iterator *iter)
-{
-        struct trace_seq *s = &iter->seq;
-        unsigned long sym_flags = (trace_flags & TRACE_ITER_SYM_MASK);
-        struct trace_event *event;
-        struct trace_entry *entry = iter->ent;
-
-        test_cpu_buff_start(iter);
-
-        event = ftrace_find_event(entry->type);
-
-        if (trace_flags & TRACE_ITER_CONTEXT_INFO) {
-                if (!trace_print_lat_context(iter))
-                        goto partial;
-        }
-
-        if (event)
-                return event->latency_trace(iter, sym_flags);
-
-        if (!trace_seq_printf(s, "Unknown type %d\n", entry->type))
-                goto partial;
-
-        return TRACE_TYPE_HANDLED;
-partial:
-        return TRACE_TYPE_PARTIAL_LINE;
-}
-
 static enum print_line_t print_trace_fmt(struct trace_iterator *iter)
 {
         struct trace_seq *s = &iter->seq;
@@ -1503,8 +1482,13 @@ static enum print_line_t print_trace_fmt(struct trace_iterator *iter)
         event = ftrace_find_event(entry->type);
 
         if (trace_flags & TRACE_ITER_CONTEXT_INFO) {
-                if (!trace_print_context(iter))
-                        goto partial;
+                if (iter->iter_flags & TRACE_FILE_LAT_FMT) {
+                        if (!trace_print_lat_context(iter))
+                                goto partial;
+                } else {
+                        if (!trace_print_context(iter))
+                                goto partial;
+                }
         }
 
         if (event)
@@ -1646,9 +1630,6 @@ static enum print_line_t print_trace_line(struct trace_iterator *iter)
         if (trace_flags & TRACE_ITER_RAW)
                 return print_raw_fmt(iter);
 
-        if (iter->iter_flags & TRACE_FILE_LAT_FMT)
-                return print_lat_fmt(iter);
-
         return print_trace_fmt(iter);
 }
 
@@ -1824,26 +1805,12 @@ static int tracing_open(struct inode *inode, struct file *file)
         iter = __tracing_open(inode, file);
         if (IS_ERR(iter))
                 ret = PTR_ERR(iter);
-
-        return ret;
-}
-
-static int tracing_lt_open(struct inode *inode, struct file *file)
-{
-        struct trace_iterator *iter;
-        int ret = 0;
-
-        iter = __tracing_open(inode, file);
-
-        if (IS_ERR(iter))
-                ret = PTR_ERR(iter);
-        else
+        else if (trace_flags & TRACE_ITER_LATENCY_FMT)
                 iter->iter_flags |= TRACE_FILE_LAT_FMT;
 
         return ret;
 }
 
-
 static void *
 t_next(struct seq_file *m, void *v, loff_t *pos)
 {
@@ -1922,13 +1889,6 @@ static struct file_operations tracing_fops = {
         .release        = tracing_release,
 };
 
-static struct file_operations tracing_lt_fops = {
-        .open           = tracing_lt_open,
-        .read           = seq_read,
-        .llseek         = seq_lseek,
-        .release        = tracing_release,
-};
-
 static struct file_operations show_traces_fops = {
         .open           = show_traces_open,
         .read           = seq_read,
@@ -3049,6 +3009,9 @@ tracing_buffers_read(struct file *filp, char __user *ubuf,
         ssize_t ret;
         size_t size;
 
+        if (!count)
+                return 0;
+
         /* Do we have previous read data to read? */
         if (info->read < PAGE_SIZE)
                 goto read;
@@ -3073,8 +3036,10 @@ read:
                 size = count;
 
         ret = copy_to_user(ubuf, info->spare + info->read, size);
-        if (ret)
+        if (ret == size)
                 return -EFAULT;
+        size -= ret;
+
         *ppos += size;
         info->read += size;
 
@@ -3918,8 +3883,10 @@ void ftrace_dump(void)
 
         printk(KERN_TRACE "Dumping ftrace buffer:\n");
 
+        /* Simulate the iterator */
         iter.tr = &global_trace;
         iter.trace = current_trace;
+        iter.cpu_file = TRACE_PIPE_ALL_CPU;
 
         /*
          * We need to stop all tracing on all CPUS to read the
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 561bb5c5d988..12cd119cca32 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -651,7 +651,8 @@ enum trace_iterator_flags {
         TRACE_ITER_USERSTACKTRACE       = 0x4000,
         TRACE_ITER_SYM_USEROBJ          = 0x8000,
         TRACE_ITER_PRINTK_MSGONLY       = 0x10000,
-        TRACE_ITER_CONTEXT_INFO         = 0x20000 /* Print pid/cpu/time */
+        TRACE_ITER_CONTEXT_INFO         = 0x20000, /* Print pid/cpu/time */
+        TRACE_ITER_LATENCY_FMT          = 0x40000,
 };
 
 /*
diff --git a/kernel/trace/trace_branch.c b/kernel/trace/trace_branch.c
index c2e68d440c4d..aaa0755268b9 100644
--- a/kernel/trace/trace_branch.c
+++ b/kernel/trace/trace_branch.c
@@ -159,7 +159,6 @@ static enum print_line_t trace_branch_print(struct trace_iterator *iter,
 static struct trace_event trace_branch_event = {
         .type           = TRACE_BRANCH,
         .trace          = trace_branch_print,
-        .latency_trace  = trace_branch_print,
 };
 
 static struct tracer branch_trace __read_mostly =
diff --git a/kernel/trace/trace_irqsoff.c b/kernel/trace/trace_irqsoff.c
index 9e5ebd844158..b923d13e2fad 100644
--- a/kernel/trace/trace_irqsoff.c
+++ b/kernel/trace/trace_irqsoff.c
@@ -32,6 +32,8 @@ enum {
 
 static int trace_type __read_mostly;
 
+static int save_lat_flag;
+
 #ifdef CONFIG_PREEMPT_TRACER
 static inline int
 preempt_trace(void)
@@ -370,6 +372,9 @@ static void stop_irqsoff_tracer(struct trace_array *tr)
 
 static void __irqsoff_tracer_init(struct trace_array *tr)
 {
+        save_lat_flag = trace_flags & TRACE_ITER_LATENCY_FMT;
+        trace_flags |= TRACE_ITER_LATENCY_FMT;
+
         tracing_max_latency = 0;
         irqsoff_trace = tr;
         /* make sure that the tracer is visible */
@@ -380,6 +385,9 @@ static void __irqsoff_tracer_init(struct trace_array *tr)
 static void irqsoff_tracer_reset(struct trace_array *tr)
 {
         stop_irqsoff_tracer(tr);
+
+        if (!save_lat_flag)
+                trace_flags &= ~TRACE_ITER_LATENCY_FMT;
 }
 
 static void irqsoff_tracer_start(struct trace_array *tr)
diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c
index 9fc815031b09..306fef84c503 100644
--- a/kernel/trace/trace_output.c
+++ b/kernel/trace/trace_output.c
@@ -437,8 +437,6 @@ int register_ftrace_event(struct trace_event *event)
 
         if (event->trace == NULL)
                 event->trace = trace_nop_print;
-        if (event->latency_trace == NULL)
-                event->latency_trace = trace_nop_print;
         if (event->raw == NULL)
                 event->raw = trace_nop_print;
         if (event->hex == NULL)
@@ -480,29 +478,6 @@ enum print_line_t trace_nop_print(struct trace_iterator *iter, int flags)
 }
 
 /* TRACE_FN */
-static enum print_line_t trace_fn_latency(struct trace_iterator *iter,
-                                          int flags)
-{
-        struct ftrace_entry *field;
-        struct trace_seq *s = &iter->seq;
-
-        trace_assign_type(field, iter->ent);
-
-        if (!seq_print_ip_sym(s, field->ip, flags))
-                goto partial;
-        if (!trace_seq_puts(s, " ("))
-                goto partial;
-        if (!seq_print_ip_sym(s, field->parent_ip, flags))
-                goto partial;
-        if (!trace_seq_puts(s, ")\n"))
-                goto partial;
-
-        return TRACE_TYPE_HANDLED;
-
- partial:
-        return TRACE_TYPE_PARTIAL_LINE;
-}
-
 static enum print_line_t trace_fn_trace(struct trace_iterator *iter, int flags)
 {
         struct ftrace_entry *field;
@@ -573,7 +548,6 @@ static enum print_line_t trace_fn_bin(struct trace_iterator *iter, int flags)
 static struct trace_event trace_fn_event = {
         .type           = TRACE_FN,
         .trace          = trace_fn_trace,
-        .latency_trace  = trace_fn_latency,
         .raw            = trace_fn_raw,
         .hex            = trace_fn_hex,
         .binary         = trace_fn_bin,
@@ -705,7 +679,6 @@ static enum print_line_t trace_ctxwake_bin(struct trace_iterator *iter,
 static struct trace_event trace_ctx_event = {
         .type           = TRACE_CTX,
         .trace          = trace_ctx_print,
-        .latency_trace  = trace_ctx_print,
         .raw            = trace_ctx_raw,
         .hex            = trace_ctx_hex,
         .binary         = trace_ctxwake_bin,
@@ -714,7 +687,6 @@ static struct trace_event trace_ctx_event = {
 static struct trace_event trace_wake_event = {
         .type           = TRACE_WAKE,
         .trace          = trace_wake_print,
-        .latency_trace  = trace_wake_print,
         .raw            = trace_wake_raw,
         .hex            = trace_wake_hex,
         .binary         = trace_ctxwake_bin,
@@ -770,7 +742,6 @@ static enum print_line_t trace_special_bin(struct trace_iterator *iter,
 static struct trace_event trace_special_event = {
         .type           = TRACE_SPECIAL,
         .trace          = trace_special_print,
-        .latency_trace  = trace_special_print,
         .raw            = trace_special_print,
         .hex            = trace_special_hex,
         .binary         = trace_special_bin,
@@ -808,7 +779,6 @@ static enum print_line_t trace_stack_print(struct trace_iterator *iter,
 static struct trace_event trace_stack_event = {
         .type           = TRACE_STACK,
         .trace          = trace_stack_print,
-        .latency_trace  = trace_stack_print,
         .raw            = trace_special_print,
         .hex            = trace_special_hex,
         .binary         = trace_special_bin,
@@ -838,7 +808,6 @@ static enum print_line_t trace_user_stack_print(struct trace_iterator *iter,
 static struct trace_event trace_user_stack_event = {
         .type           = TRACE_USER_STACK,
         .trace          = trace_user_stack_print,
-        .latency_trace  = trace_user_stack_print,
         .raw            = trace_special_print,
         .hex            = trace_special_hex,
         .binary         = trace_special_bin,
@@ -883,7 +852,6 @@ static enum print_line_t trace_print_raw(struct trace_iterator *iter, int flags)
 static struct trace_event trace_print_event = {
         .type           = TRACE_PRINT,
         .trace          = trace_print_print,
-        .latency_trace  = trace_print_print,
         .raw            = trace_print_raw,
 };
 
diff --git a/kernel/trace/trace_output.h b/kernel/trace/trace_output.h
index 551a25a72217..8a34d688ed63 100644
--- a/kernel/trace/trace_output.h
+++ b/kernel/trace/trace_output.h
@@ -10,7 +10,6 @@ struct trace_event {
         struct hlist_node       node;
         int                     type;
         trace_print_func        trace;
-        trace_print_func        latency_trace;
         trace_print_func        raw;
         trace_print_func        hex;
         trace_print_func        binary;
diff --git a/kernel/trace/trace_sched_wakeup.c b/kernel/trace/trace_sched_wakeup.c
index db55f7aaa640..3c5ad6b2ec84 100644
--- a/kernel/trace/trace_sched_wakeup.c
+++ b/kernel/trace/trace_sched_wakeup.c
@@ -32,6 +32,8 @@ static raw_spinlock_t wakeup_lock =
 
 static void __wakeup_reset(struct trace_array *tr);
 
+static int save_lat_flag;
+
 #ifdef CONFIG_FUNCTION_TRACER
 /*
  * irqsoff uses its own tracer function to keep the overhead down:
@@ -324,6 +326,9 @@ static void stop_wakeup_tracer(struct trace_array *tr)
 
 static int __wakeup_tracer_init(struct trace_array *tr)
 {
+        save_lat_flag = trace_flags & TRACE_ITER_LATENCY_FMT;
+        trace_flags |= TRACE_ITER_LATENCY_FMT;
+
         tracing_max_latency = 0;
         wakeup_trace = tr;
         start_wakeup_tracer(tr);
@@ -347,6 +352,9 @@ static void wakeup_tracer_reset(struct trace_array *tr)
         stop_wakeup_tracer(tr);
         /* make sure we put back any tasks we are tracing */
         wakeup_reset(tr);
+
+        if (!save_lat_flag)
+                trace_flags &= ~TRACE_ITER_LATENCY_FMT;
 }
 
 static void wakeup_tracer_start(struct trace_array *tr)