cpuset,mm: fix no node to alloc memory when changing cpuset's mems

[safe/jmp/linux-2.6] / kernel / trace / trace_nop.c

diff --git a/kernel/trace/trace_nop.c b/kernel/trace/trace_nop.c
index 4592b48..394f944 100644 (file)
--- a/kernel/trace/trace_nop.c
+++ b/kernel/trace/trace_nop.c
@@ -12,6 +12,27 @@
 
 #include "trace.h"
 
+/* Our two options */
+enum {
+       TRACE_NOP_OPT_ACCEPT = 0x1,
+       TRACE_NOP_OPT_REFUSE = 0x2
+};
+
+/* Options for the tracer (see trace_options file) */
+static struct tracer_opt nop_opts[] = {
+       /* Option that will be accepted by set_flag callback */
+       { TRACER_OPT(test_nop_accept, TRACE_NOP_OPT_ACCEPT) },
+       /* Option that will be refused by set_flag callback */
+       { TRACER_OPT(test_nop_refuse, TRACE_NOP_OPT_REFUSE) },
+       { } /* Always set a last empty entry */
+};
+
+static struct tracer_flags nop_flags = {
+       /* You can check your flags value here when you want. */
+       .val = 0, /* By default: all flags disabled */
+       .opts = nop_opts
+};
+
 static struct trace_array      *ctx_trace;
 
 static void start_nop_trace(struct trace_array *tr)
@@ -24,41 +45,57 @@ static void stop_nop_trace(struct trace_array *tr)
        /* Nothing to do! */
 }
 
-static void nop_trace_init(struct trace_array *tr)
+static int nop_trace_init(struct trace_array *tr)
 {
-       int cpu;
        ctx_trace = tr;
-
-       for_each_online_cpu(cpu)
-               tracing_reset(tr, cpu);
-
-       if (tr->ctrl)
-               start_nop_trace(tr);
+       start_nop_trace(tr);
+       return 0;
 }
 
 static void nop_trace_reset(struct trace_array *tr)
 {
-       if (tr->ctrl)
-               stop_nop_trace(tr);
+       stop_nop_trace(tr);
 }
 
-static void nop_trace_ctrl_update(struct trace_array *tr)
+/* It only serves as a signal handler and a callback to
+ * accept or refuse tthe setting of a flag.
+ * If you don't implement it, then the flag setting will be
+ * automatically accepted.
+ */
+static int nop_set_flag(u32 old_flags, u32 bit, int set)
 {
-       /* When starting a new trace, reset the buffers */
-       if (tr->ctrl)
-               start_nop_trace(tr);
-       else
-               stop_nop_trace(tr);
+       /*
+        * Note that you don't need to update nop_flags.val yourself.
+        * The tracing Api will do it automatically if you return 0
+        */
+       if (bit == TRACE_NOP_OPT_ACCEPT) {
+               printk(KERN_DEBUG "nop_test_accept flag set to %d: we accept."
+                       " Now cat trace_options to see the result\n",
+                       set);
+               return 0;
+       }
+
+       if (bit == TRACE_NOP_OPT_REFUSE) {
+               printk(KERN_DEBUG "nop_test_refuse flag set to %d: we refuse."
+                       "Now cat trace_options to see the result\n",
+                       set);
+               return -EINVAL;
+       }
+
+       return 0;
 }
 
+
 struct tracer nop_trace __read_mostly =
 {
        .name           = "nop",
        .init           = nop_trace_init,
        .reset          = nop_trace_reset,
-       .ctrl_update    = nop_trace_ctrl_update,
+       .wait_pipe      = poll_wait_pipe,
 #ifdef CONFIG_FTRACE_SELFTEST
        .selftest       = trace_selftest_startup_nop,
 #endif
+       .flags          = &nop_flags,
+       .set_flag       = nop_set_flag
 };