tracing: infrastructure for supporting binary record

Impact: save on memory for tracing

Current tracers are typically using a struct(like struct ftrace_entry,
struct ctx_switch_entry, struct special_entr etc...)to record a binary
event. These structs can only record a their own kind of events.
A new kind of tracer need a new struct and a lot of code too handle it.

So we need a generic binary record for events. This infrastructure
is for this purpose.

[fweisbec@gmail.com: rebase against latest -tip, make it safe while sched
tracing as reported by Steven Rostedt]

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <1236356510-8381-3-git-send-email-fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 12 insertions, 0 deletions

diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 8beff03fda68..0f5077f8f957 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -20,6 +20,7 @@ enum trace_type {
         TRACE_WAKE,
         TRACE_STACK,
         TRACE_PRINT,
+        TRACE_BPRINTK,
         TRACE_SPECIAL,
         TRACE_MMIO_RW,
         TRACE_MMIO_MAP,
@@ -124,6 +125,16 @@ struct print_entry {
         char                    buf[];
 };
 
+struct bprintk_entry {
+        struct trace_entry ent;
+        unsigned long ip;
+        const char *fmt;
+        u32 buf[];
+};
+#ifdef CONFIG_TRACE_BPRINTK
+extern int trace_bprintk_enable;
+#endif
+
 #define TRACE_OLD_SIZE          88
 
 struct trace_field_cont {
@@ -285,6 +296,7 @@ extern void __ftrace_bad_type(void);
                 IF_ASSIGN(var, ent, struct stack_entry, TRACE_STACK);   \
                 IF_ASSIGN(var, ent, struct userstack_entry, TRACE_USER_STACK);\
                 IF_ASSIGN(var, ent, struct print_entry, TRACE_PRINT);   \
+                IF_ASSIGN(var, ent, struct bprintk_entry, TRACE_BPRINTK);\
                 IF_ASSIGN(var, ent, struct special_entry, 0);           \
                 IF_ASSIGN(var, ent, struct trace_mmiotrace_rw,          \
                           TRACE_MMIO_RW);                               \