Re: [PATCH 02/32] tracing: Reimplement log2

2017-07-14 Thread Tom Zanussi 
Hi Namhyung,

On Fri, 2017-07-14 at 11:33 +0900, Namhyung Kim wrote:
> On Mon, Jun 26, 2017 at 05:49:03PM -0500, Tom Zanussi wrote:
> > log2 as currently implemented applies only to u64 trace_event_field
> > derived fields, and assumes that anything it's applied to is a u64
> > field.
> > 
> > To prepare for synthetic fields like latencies, log2 should be
> > applicable to those as well, so take the opportunity now to fix the
> > current problems as well as expand to more general uses.
> > 
> > log2 should be thought of as a chaining function rather than a field
> > type.  To enable this as well as possible future function
> > implementations, add a hist_field operand array into the hist_field
> > definition for this purpose, and make use of it to implement the log2
> > 'function'.
> > 
> > Signed-off-by: Tom Zanussi 
> > ---
> >  kernel/trace/trace_events_hist.c | 31 +++
> >  1 file changed, 27 insertions(+), 4 deletions(-)
> > 
> > diff --git a/kernel/trace/trace_events_hist.c 
> > b/kernel/trace/trace_events_hist.c
> > index 91ffc39..7b55956 100644
> > --- a/kernel/trace/trace_events_hist.c
> > +++ b/kernel/trace/trace_events_hist.c
> > @@ -28,12 +28,16 @@
> >  
> >  typedef u64 (*hist_field_fn_t) (struct hist_field *field, void *event);
> >  
> > +#define HIST_FIELD_OPERANDS_MAX2
> > +
> >  struct hist_field {
> > struct ftrace_event_field   *field;
> > unsigned long   flags;
> > hist_field_fn_t fn;
> > unsigned intsize;
> > unsigned intoffset;
> > +   unsigned intis_signed;
> > +   struct hist_field   *operands[HIST_FIELD_OPERANDS_MAX];
> >  };
> >  
> >  static u64 hist_field_none(struct hist_field *field, void *event)
> > @@ -71,7 +75,9 @@ static u64 hist_field_pstring(struct hist_field 
> > *hist_field, void *event)
> >  
> >  static u64 hist_field_log2(struct hist_field *hist_field, void *event)
> >  {
> > -   u64 val = *(u64 *)(event + hist_field->field->offset);
> > +   struct hist_field *operand = hist_field->operands[0];
> > +
> > +   u64 val = operand->fn(operand, event);
> >  
> > return (u64) ilog2(roundup_pow_of_two(val));
> >  }
> > @@ -156,6 +162,8 @@ static const char *hist_field_name(struct hist_field 
> > *field,
> >  
> > if (field->field)
> > field_name = field->field->name;
> > +   else if (field->flags & HIST_FIELD_FL_LOG2)
> > +   field_name = hist_field_name(field->operands[0], ++level);
> >  
> > if (field_name == NULL)
> > field_name = "";
> > @@ -357,8 +365,20 @@ static void hist_trigger_elt_comm_init(struct 
> > tracing_map_elt *elt)
> > .elt_init   = hist_trigger_elt_comm_init,
> >  };
> >  
> > -static void destroy_hist_field(struct hist_field *hist_field)
> > +static void destroy_hist_field(struct hist_field *hist_field,
> > +  unsigned int level)
> >  {
> > +   unsigned int i;
> > +
> > +   if (level > 2)
> > +   return;
> > +
> > +   if (!hist_field)
> > +   return;
> > +
> > +   for (i = 0; i < HIST_FIELD_OPERANDS_MAX; i++)
> > +   destroy_hist_field(hist_field->operands[i], ++level);
> 
> Wouldn't it be 'level + 1' ?
> 

Yeah, we're in a loop here, so definitely.  Thanks for catching this.

Tom

> Thanks,
> Namhyung
> 
> 
> > +
> > kfree(hist_field);
> >  }

Re: [PATCH 02/32] tracing: Reimplement log2

2017-07-14 Thread Tom Zanussi 
Hi Namhyung,

On Fri, 2017-07-14 at 11:33 +0900, Namhyung Kim wrote:
> On Mon, Jun 26, 2017 at 05:49:03PM -0500, Tom Zanussi wrote:
> > log2 as currently implemented applies only to u64 trace_event_field
> > derived fields, and assumes that anything it's applied to is a u64
> > field.
> > 
> > To prepare for synthetic fields like latencies, log2 should be
> > applicable to those as well, so take the opportunity now to fix the
> > current problems as well as expand to more general uses.
> > 
> > log2 should be thought of as a chaining function rather than a field
> > type.  To enable this as well as possible future function
> > implementations, add a hist_field operand array into the hist_field
> > definition for this purpose, and make use of it to implement the log2
> > 'function'.
> > 
> > Signed-off-by: Tom Zanussi 
> > ---
> >  kernel/trace/trace_events_hist.c | 31 +++
> >  1 file changed, 27 insertions(+), 4 deletions(-)
> > 
> > diff --git a/kernel/trace/trace_events_hist.c 
> > b/kernel/trace/trace_events_hist.c
> > index 91ffc39..7b55956 100644
> > --- a/kernel/trace/trace_events_hist.c
> > +++ b/kernel/trace/trace_events_hist.c
> > @@ -28,12 +28,16 @@
> >  
> >  typedef u64 (*hist_field_fn_t) (struct hist_field *field, void *event);
> >  
> > +#define HIST_FIELD_OPERANDS_MAX2
> > +
> >  struct hist_field {
> > struct ftrace_event_field   *field;
> > unsigned long   flags;
> > hist_field_fn_t fn;
> > unsigned intsize;
> > unsigned intoffset;
> > +   unsigned intis_signed;
> > +   struct hist_field   *operands[HIST_FIELD_OPERANDS_MAX];
> >  };
> >  
> >  static u64 hist_field_none(struct hist_field *field, void *event)
> > @@ -71,7 +75,9 @@ static u64 hist_field_pstring(struct hist_field 
> > *hist_field, void *event)
> >  
> >  static u64 hist_field_log2(struct hist_field *hist_field, void *event)
> >  {
> > -   u64 val = *(u64 *)(event + hist_field->field->offset);
> > +   struct hist_field *operand = hist_field->operands[0];
> > +
> > +   u64 val = operand->fn(operand, event);
> >  
> > return (u64) ilog2(roundup_pow_of_two(val));
> >  }
> > @@ -156,6 +162,8 @@ static const char *hist_field_name(struct hist_field 
> > *field,
> >  
> > if (field->field)
> > field_name = field->field->name;
> > +   else if (field->flags & HIST_FIELD_FL_LOG2)
> > +   field_name = hist_field_name(field->operands[0], ++level);
> >  
> > if (field_name == NULL)
> > field_name = "";
> > @@ -357,8 +365,20 @@ static void hist_trigger_elt_comm_init(struct 
> > tracing_map_elt *elt)
> > .elt_init   = hist_trigger_elt_comm_init,
> >  };
> >  
> > -static void destroy_hist_field(struct hist_field *hist_field)
> > +static void destroy_hist_field(struct hist_field *hist_field,
> > +  unsigned int level)
> >  {
> > +   unsigned int i;
> > +
> > +   if (level > 2)
> > +   return;
> > +
> > +   if (!hist_field)
> > +   return;
> > +
> > +   for (i = 0; i < HIST_FIELD_OPERANDS_MAX; i++)
> > +   destroy_hist_field(hist_field->operands[i], ++level);
> 
> Wouldn't it be 'level + 1' ?
> 

Yeah, we're in a loop here, so definitely.  Thanks for catching this.

Tom

> Thanks,
> Namhyung
> 
> 
> > +
> > kfree(hist_field);
> >  }

Re: [PATCH 02/32] tracing: Reimplement log2

2017-07-13 Thread Namhyung Kim 
On Mon, Jun 26, 2017 at 05:49:03PM -0500, Tom Zanussi wrote:
> log2 as currently implemented applies only to u64 trace_event_field
> derived fields, and assumes that anything it's applied to is a u64
> field.
> 
> To prepare for synthetic fields like latencies, log2 should be
> applicable to those as well, so take the opportunity now to fix the
> current problems as well as expand to more general uses.
> 
> log2 should be thought of as a chaining function rather than a field
> type.  To enable this as well as possible future function
> implementations, add a hist_field operand array into the hist_field
> definition for this purpose, and make use of it to implement the log2
> 'function'.
> 
> Signed-off-by: Tom Zanussi 
> ---
>  kernel/trace/trace_events_hist.c | 31 +++
>  1 file changed, 27 insertions(+), 4 deletions(-)
> 
> diff --git a/kernel/trace/trace_events_hist.c 
> b/kernel/trace/trace_events_hist.c
> index 91ffc39..7b55956 100644
> --- a/kernel/trace/trace_events_hist.c
> +++ b/kernel/trace/trace_events_hist.c
> @@ -28,12 +28,16 @@
>  
>  typedef u64 (*hist_field_fn_t) (struct hist_field *field, void *event);
>  
> +#define HIST_FIELD_OPERANDS_MAX  2
> +
>  struct hist_field {
>   struct ftrace_event_field   *field;
>   unsigned long   flags;
>   hist_field_fn_t fn;
>   unsigned intsize;
>   unsigned intoffset;
> + unsigned intis_signed;
> + struct hist_field   *operands[HIST_FIELD_OPERANDS_MAX];
>  };
>  
>  static u64 hist_field_none(struct hist_field *field, void *event)
> @@ -71,7 +75,9 @@ static u64 hist_field_pstring(struct hist_field 
> *hist_field, void *event)
>  
>  static u64 hist_field_log2(struct hist_field *hist_field, void *event)
>  {
> - u64 val = *(u64 *)(event + hist_field->field->offset);
> + struct hist_field *operand = hist_field->operands[0];
> +
> + u64 val = operand->fn(operand, event);
>  
>   return (u64) ilog2(roundup_pow_of_two(val));
>  }
> @@ -156,6 +162,8 @@ static const char *hist_field_name(struct hist_field 
> *field,
>  
>   if (field->field)
>   field_name = field->field->name;
> + else if (field->flags & HIST_FIELD_FL_LOG2)
> + field_name = hist_field_name(field->operands[0], ++level);
>  
>   if (field_name == NULL)
>   field_name = "";
> @@ -357,8 +365,20 @@ static void hist_trigger_elt_comm_init(struct 
> tracing_map_elt *elt)
>   .elt_init   = hist_trigger_elt_comm_init,
>  };
>  
> -static void destroy_hist_field(struct hist_field *hist_field)
> +static void destroy_hist_field(struct hist_field *hist_field,
> +unsigned int level)
>  {
> + unsigned int i;
> +
> + if (level > 2)
> + return;
> +
> + if (!hist_field)
> + return;
> +
> + for (i = 0; i < HIST_FIELD_OPERANDS_MAX; i++)
> + destroy_hist_field(hist_field->operands[i], ++level);

Wouldn't it be 'level + 1' ?

Thanks,
Namhyung


> +
>   kfree(hist_field);
>  }

Re: [PATCH 02/32] tracing: Reimplement log2

2017-07-13 Thread Namhyung Kim 
On Mon, Jun 26, 2017 at 05:49:03PM -0500, Tom Zanussi wrote:
> log2 as currently implemented applies only to u64 trace_event_field
> derived fields, and assumes that anything it's applied to is a u64
> field.
> 
> To prepare for synthetic fields like latencies, log2 should be
> applicable to those as well, so take the opportunity now to fix the
> current problems as well as expand to more general uses.
> 
> log2 should be thought of as a chaining function rather than a field
> type.  To enable this as well as possible future function
> implementations, add a hist_field operand array into the hist_field
> definition for this purpose, and make use of it to implement the log2
> 'function'.
> 
> Signed-off-by: Tom Zanussi 
> ---
>  kernel/trace/trace_events_hist.c | 31 +++
>  1 file changed, 27 insertions(+), 4 deletions(-)
> 
> diff --git a/kernel/trace/trace_events_hist.c 
> b/kernel/trace/trace_events_hist.c
> index 91ffc39..7b55956 100644
> --- a/kernel/trace/trace_events_hist.c
> +++ b/kernel/trace/trace_events_hist.c
> @@ -28,12 +28,16 @@
>  
>  typedef u64 (*hist_field_fn_t) (struct hist_field *field, void *event);
>  
> +#define HIST_FIELD_OPERANDS_MAX  2
> +
>  struct hist_field {
>   struct ftrace_event_field   *field;
>   unsigned long   flags;
>   hist_field_fn_t fn;
>   unsigned intsize;
>   unsigned intoffset;
> + unsigned intis_signed;
> + struct hist_field   *operands[HIST_FIELD_OPERANDS_MAX];
>  };
>  
>  static u64 hist_field_none(struct hist_field *field, void *event)
> @@ -71,7 +75,9 @@ static u64 hist_field_pstring(struct hist_field 
> *hist_field, void *event)
>  
>  static u64 hist_field_log2(struct hist_field *hist_field, void *event)
>  {
> - u64 val = *(u64 *)(event + hist_field->field->offset);
> + struct hist_field *operand = hist_field->operands[0];
> +
> + u64 val = operand->fn(operand, event);
>  
>   return (u64) ilog2(roundup_pow_of_two(val));
>  }
> @@ -156,6 +162,8 @@ static const char *hist_field_name(struct hist_field 
> *field,
>  
>   if (field->field)
>   field_name = field->field->name;
> + else if (field->flags & HIST_FIELD_FL_LOG2)
> + field_name = hist_field_name(field->operands[0], ++level);
>  
>   if (field_name == NULL)
>   field_name = "";
> @@ -357,8 +365,20 @@ static void hist_trigger_elt_comm_init(struct 
> tracing_map_elt *elt)
>   .elt_init   = hist_trigger_elt_comm_init,
>  };
>  
> -static void destroy_hist_field(struct hist_field *hist_field)
> +static void destroy_hist_field(struct hist_field *hist_field,
> +unsigned int level)
>  {
> + unsigned int i;
> +
> + if (level > 2)
> + return;
> +
> + if (!hist_field)
> + return;
> +
> + for (i = 0; i < HIST_FIELD_OPERANDS_MAX; i++)
> + destroy_hist_field(hist_field->operands[i], ++level);

Wouldn't it be 'level + 1' ?

Thanks,
Namhyung


> +
>   kfree(hist_field);
>  }

[PATCH 02/32] tracing: Reimplement log2

2017-06-26 Thread Tom Zanussi 
log2 as currently implemented applies only to u64 trace_event_field
derived fields, and assumes that anything it's applied to is a u64
field.

To prepare for synthetic fields like latencies, log2 should be
applicable to those as well, so take the opportunity now to fix the
current problems as well as expand to more general uses.

log2 should be thought of as a chaining function rather than a field
type.  To enable this as well as possible future function
implementations, add a hist_field operand array into the hist_field
definition for this purpose, and make use of it to implement the log2
'function'.

Signed-off-by: Tom Zanussi 
---
 kernel/trace/trace_events_hist.c | 31 +++
 1 file changed, 27 insertions(+), 4 deletions(-)

diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
index 91ffc39..7b55956 100644
--- a/kernel/trace/trace_events_hist.c
+++ b/kernel/trace/trace_events_hist.c
@@ -28,12 +28,16 @@
 
 typedef u64 (*hist_field_fn_t) (struct hist_field *field, void *event);
 
+#define HIST_FIELD_OPERANDS_MAX2
+
 struct hist_field {
struct ftrace_event_field   *field;
unsigned long   flags;
hist_field_fn_t fn;
unsigned intsize;
unsigned intoffset;
+   unsigned intis_signed;
+   struct hist_field   *operands[HIST_FIELD_OPERANDS_MAX];
 };
 
 static u64 hist_field_none(struct hist_field *field, void *event)
@@ -71,7 +75,9 @@ static u64 hist_field_pstring(struct hist_field *hist_field, 
void *event)
 
 static u64 hist_field_log2(struct hist_field *hist_field, void *event)
 {
-   u64 val = *(u64 *)(event + hist_field->field->offset);
+   struct hist_field *operand = hist_field->operands[0];
+
+   u64 val = operand->fn(operand, event);
 
return (u64) ilog2(roundup_pow_of_two(val));
 }
@@ -156,6 +162,8 @@ static const char *hist_field_name(struct hist_field *field,
 
if (field->field)
field_name = field->field->name;
+   else if (field->flags & HIST_FIELD_FL_LOG2)
+   field_name = hist_field_name(field->operands[0], ++level);
 
if (field_name == NULL)
field_name = "";
@@ -357,8 +365,20 @@ static void hist_trigger_elt_comm_init(struct 
tracing_map_elt *elt)
.elt_init   = hist_trigger_elt_comm_init,
 };
 
-static void destroy_hist_field(struct hist_field *hist_field)
+static void destroy_hist_field(struct hist_field *hist_field,
+  unsigned int level)
 {
+   unsigned int i;
+
+   if (level > 2)
+   return;
+
+   if (!hist_field)
+   return;
+
+   for (i = 0; i < HIST_FIELD_OPERANDS_MAX; i++)
+   destroy_hist_field(hist_field->operands[i], ++level);
+
kfree(hist_field);
 }
 
@@ -385,7 +405,10 @@ static struct hist_field *create_hist_field(struct 
ftrace_event_field *field,
}
 
if (flags & HIST_FIELD_FL_LOG2) {
+   unsigned long fl = flags & ~HIST_FIELD_FL_LOG2;
hist_field->fn = hist_field_log2;
+   hist_field->operands[0] = create_hist_field(field, fl);
+   hist_field->size = hist_field->operands[0]->size;
goto out;
}
 
@@ -405,7 +428,7 @@ static struct hist_field *create_hist_field(struct 
ftrace_event_field *field,
hist_field->fn = select_value_fn(field->size,
 field->is_signed);
if (!hist_field->fn) {
-   destroy_hist_field(hist_field);
+   destroy_hist_field(hist_field, 0);
return NULL;
}
}
@@ -422,7 +445,7 @@ static void destroy_hist_fields(struct hist_trigger_data 
*hist_data)
 
for (i = 0; i < TRACING_MAP_FIELDS_MAX; i++) {
if (hist_data->fields[i]) {
-   destroy_hist_field(hist_data->fields[i]);
+   destroy_hist_field(hist_data->fields[i], 0);
hist_data->fields[i] = NULL;
}
}
-- 
1.9.3

[PATCH 02/32] tracing: Reimplement log2

2017-06-26 Thread Tom Zanussi 
log2 as currently implemented applies only to u64 trace_event_field
derived fields, and assumes that anything it's applied to is a u64
field.

To prepare for synthetic fields like latencies, log2 should be
applicable to those as well, so take the opportunity now to fix the
current problems as well as expand to more general uses.

log2 should be thought of as a chaining function rather than a field
type.  To enable this as well as possible future function
implementations, add a hist_field operand array into the hist_field
definition for this purpose, and make use of it to implement the log2
'function'.

Signed-off-by: Tom Zanussi 
---
 kernel/trace/trace_events_hist.c | 31 +++
 1 file changed, 27 insertions(+), 4 deletions(-)

diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
index 91ffc39..7b55956 100644
--- a/kernel/trace/trace_events_hist.c
+++ b/kernel/trace/trace_events_hist.c
@@ -28,12 +28,16 @@
 
 typedef u64 (*hist_field_fn_t) (struct hist_field *field, void *event);
 
+#define HIST_FIELD_OPERANDS_MAX2
+
 struct hist_field {
struct ftrace_event_field   *field;
unsigned long   flags;
hist_field_fn_t fn;
unsigned intsize;
unsigned intoffset;
+   unsigned intis_signed;
+   struct hist_field   *operands[HIST_FIELD_OPERANDS_MAX];
 };
 
 static u64 hist_field_none(struct hist_field *field, void *event)
@@ -71,7 +75,9 @@ static u64 hist_field_pstring(struct hist_field *hist_field, 
void *event)
 
 static u64 hist_field_log2(struct hist_field *hist_field, void *event)
 {
-   u64 val = *(u64 *)(event + hist_field->field->offset);
+   struct hist_field *operand = hist_field->operands[0];
+
+   u64 val = operand->fn(operand, event);
 
return (u64) ilog2(roundup_pow_of_two(val));
 }
@@ -156,6 +162,8 @@ static const char *hist_field_name(struct hist_field *field,
 
if (field->field)
field_name = field->field->name;
+   else if (field->flags & HIST_FIELD_FL_LOG2)
+   field_name = hist_field_name(field->operands[0], ++level);
 
if (field_name == NULL)
field_name = "";
@@ -357,8 +365,20 @@ static void hist_trigger_elt_comm_init(struct 
tracing_map_elt *elt)
.elt_init   = hist_trigger_elt_comm_init,
 };
 
-static void destroy_hist_field(struct hist_field *hist_field)
+static void destroy_hist_field(struct hist_field *hist_field,
+  unsigned int level)
 {
+   unsigned int i;
+
+   if (level > 2)
+   return;
+
+   if (!hist_field)
+   return;
+
+   for (i = 0; i < HIST_FIELD_OPERANDS_MAX; i++)
+   destroy_hist_field(hist_field->operands[i], ++level);
+
kfree(hist_field);
 }
 
@@ -385,7 +405,10 @@ static struct hist_field *create_hist_field(struct 
ftrace_event_field *field,
}
 
if (flags & HIST_FIELD_FL_LOG2) {
+   unsigned long fl = flags & ~HIST_FIELD_FL_LOG2;
hist_field->fn = hist_field_log2;
+   hist_field->operands[0] = create_hist_field(field, fl);
+   hist_field->size = hist_field->operands[0]->size;
goto out;
}
 
@@ -405,7 +428,7 @@ static struct hist_field *create_hist_field(struct 
ftrace_event_field *field,
hist_field->fn = select_value_fn(field->size,
 field->is_signed);
if (!hist_field->fn) {
-   destroy_hist_field(hist_field);
+   destroy_hist_field(hist_field, 0);
return NULL;
}
}
@@ -422,7 +445,7 @@ static void destroy_hist_fields(struct hist_trigger_data 
*hist_data)
 
for (i = 0; i < TRACING_MAP_FIELDS_MAX; i++) {
if (hist_data->fields[i]) {
-   destroy_hist_field(hist_data->fields[i]);
+   destroy_hist_field(hist_data->fields[i], 0);
hist_data->fields[i] = NULL;
}
}
-- 
1.9.3