Impact: give an example on how to use specific tracer flags
This patch propose to use the nop tracer to provide an
example for using the tracer's custom flags implementation.
Signed-off-by: Frederic Weisbecker <[email protected]>
---
kernel/trace/trace_nop.c | 48 ++++++++++++++++++++++++++++++++++++++++++++++
1 files changed, 48 insertions(+), 0 deletions(-)
diff --git a/kernel/trace/trace_nop.c b/kernel/trace/trace_nop.c
index 0e77415..1d8b4f8 100644
--- a/kernel/trace/trace_nop.c
+++ b/kernel/trace/trace_nop.c
@@ -41,6 +41,52 @@ static void nop_trace_reset(struct trace_array *tr)
stop_nop_trace(tr);
}
+#define TRACE_NOP_OPT_ACCEPT 0x1
+#define 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 the 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
+};
+
+/* 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)
+{
+ /*
+ * 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",
@@ -49,5 +95,7 @@ struct tracer nop_trace __read_mostly =
#ifdef CONFIG_FTRACE_SELFTEST
.selftest = trace_selftest_startup_nop,
#endif
+ .flags = &nop_flags,
+ .set_flag = nop_set_flag
};
--
1.5.2.5
On Sun, Nov 16, 2008 at 6:19 PM, Frederic Weisbecker <[email protected]> wrote:
> Impact: give an example on how to use specific tracer flags
>
> This patch propose to use the nop tracer to provide an
> example for using the tracer's custom flags implementation.
>
> Signed-off-by: Frederic Weisbecker <[email protected]>
> ---
> kernel/trace/trace_nop.c | 48 ++++++++++++++++++++++++++++++++++++++++++++++
> 1 files changed, 48 insertions(+), 0 deletions(-)
>
> diff --git a/kernel/trace/trace_nop.c b/kernel/trace/trace_nop.c
> index 0e77415..1d8b4f8 100644
> --- a/kernel/trace/trace_nop.c
> +++ b/kernel/trace/trace_nop.c
> @@ -41,6 +41,52 @@ static void nop_trace_reset(struct trace_array *tr)
> stop_nop_trace(tr);
> }
>
> +#define TRACE_NOP_OPT_ACCEPT 0x1
> +#define 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 the 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
> +};
I'd like these #defines and structs moved to just after the #includes,
for cleanliness.
> +
> +/* 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)
> +{
> + /*
> + * 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",
> @@ -49,5 +95,7 @@ struct tracer nop_trace __read_mostly =
> #ifdef CONFIG_FTRACE_SELFTEST
> .selftest = trace_selftest_startup_nop,
> #endif
> + .flags = &nop_flags,
> + .set_flag = nop_set_flag
> };
>
> --
> 1.5.2.5
>
Other than the change noted above, I think it looks good.
Acked-by: Steven Noonan <[email protected]>
Steven Noonan a ?crit :
> I'd like these #defines and structs moved to just after the #includes,
> for cleanliness.
You're right I just corrected it in this V2.
> Other than the change noted above, I think it looks good.
>
> Acked-by: Steven Noonan <[email protected]>
Thanks!
Here is the V2:
--
>From 6611913ca6ab732277b187283dba2144af4c9548 Mon Sep 17 00:00:00 2001
From: Frederic Weisbecker <[email protected]>
Date: Mon, 17 Nov 2008 03:53:33 +0100
Subject: [PATCH 2/3][V2] tracing/ftrace: make nop tracer using tracer flags
Impact: give an example on how to use specific tracer flags
This patch propose to use the nop tracer to provide an
example for using the tracer's custom flags implementation.
(V2: replace structures and defines just after the headers includes for
cleanliness).
Signed-off-by: Frederic Weisbecker <[email protected]>
Acked-by: Steven Noonan <[email protected]>
---
diff --git a/kernel/trace/trace_nop.c b/kernel/trace/trace_nop.c
index 0e77415..c917789 100644
--- a/kernel/trace/trace_nop.c
+++ b/kernel/trace/trace_nop.c
@@ -12,6 +12,23 @@
#include "trace.h"
+#define TRACE_NOP_OPT_ACCEPT 0x1
+#define 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)
@@ -41,6 +58,35 @@ static void nop_trace_reset(struct trace_array *tr)
stop_nop_trace(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)
+{
+ /*
+ * 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",
@@ -49,5 +95,7 @@ struct tracer nop_trace __read_mostly =
#ifdef CONFIG_FTRACE_SELFTEST
.selftest = trace_selftest_startup_nop,
#endif
+ .flags = &nop_flags,
+ .set_flag = nop_set_flag
};
--
1.5.2.5
* Frederic Weisbecker <[email protected]> wrote:
> +#define TRACE_NOP_OPT_ACCEPT 0x1
> +#define TRACE_NOP_OPT_REFUSE 0x2
please use C enums not CPP defines.
Ingo
Ingo Molnar a ?crit :
> * Frederic Weisbecker <[email protected]> wrote:
>
>> +#define TRACE_NOP_OPT_ACCEPT 0x1
>> +#define TRACE_NOP_OPT_REFUSE 0x2
>
> please use C enums not CPP defines.
>
> Ingo
Fixed in the V3 below:
--
>From adc63c6d8f79927740058a50679a94a1c31c30e2 Mon Sep 17 00:00:00 2001
From: Frederic Weisbecker <[email protected]>
Date: Mon, 17 Nov 2008 16:19:35 +0100
Subject: [PATCH 2/3][V3] tracing/ftrace: make nop tracer using tracer flags
Impact: give an example on how to use specific tracer flags
This patch propose to use the nop tracer to provide an
example for using the tracer's custom flags implementation.
V3: replace defines by enum values.
V2: replace structures and defines just after the headers includes for
cleanliness.
Acked-by: Steven Noonan <[email protected]>
Signed-off-by: Frederic Weisbecker <[email protected]>
---
kernel/trace/trace_nop.c | 52 ++++++++++++++++++++++++++++++++++++++++++++++
1 files changed, 52 insertions(+), 0 deletions(-)
diff --git a/kernel/trace/trace_nop.c b/kernel/trace/trace_nop.c
index 0e77415..b9767ac 100644
--- 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)
@@ -41,6 +62,35 @@ static void nop_trace_reset(struct trace_array *tr)
stop_nop_trace(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)
+{
+ /*
+ * 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",
@@ -49,5 +99,7 @@ struct tracer nop_trace __read_mostly =
#ifdef CONFIG_FTRACE_SELFTEST
.selftest = trace_selftest_startup_nop,
#endif
+ .flags = &nop_flags,
+ .set_flag = nop_set_flag
};
--
1.5.2.5
* Frederic Weisbecker <[email protected]> wrote:
> Steven Noonan a ?crit :
> > I'd like these #defines and structs moved to just after the #includes,
> > for cleanliness.
>
> You're right I just corrected it in this V2.
>
>
> > Other than the change noted above, I think it looks good.
> >
> > Acked-by: Steven Noonan <[email protected]>
>
> Thanks!
>
> Here is the V2:
thanks.
Steve, what's your take on this method of allowing extensions to
tracer plugins? I've put Frederic's commits into tip/tracing/options,
but have not merged them into tip/master yet.
Ingo
On Tue, 18 Nov 2008, Ingo Molnar wrote:
>
> * Frederic Weisbecker <[email protected]> wrote:
>
> > Steven Noonan a ?crit :
> > > I'd like these #defines and structs moved to just after the #includes,
> > > for cleanliness.
> >
> > You're right I just corrected it in this V2.
> >
> >
> > > Other than the change noted above, I think it looks good.
> > >
> > > Acked-by: Steven Noonan <[email protected]>
> >
> > Thanks!
> >
> > Here is the V2:
>
> thanks.
>
> Steve, what's your take on this method of allowing extensions to
> tracer plugins? I've put Frederic's commits into tip/tracing/options,
> but have not merged them into tip/master yet.
I'll pull it now and play with it to see if there's any issues I might
find. But from looking at the patches, I do not see anything major.
I'll let you know.
-- Steve