[v3,2/6] trace: support dereferencing arguments

Message ID 20250210174424.3364021-3-david.marchand@redhat.com (mailing list archive)
State Superseded
Delegated to: Thomas Monjalon
Headers
Series Trace point framework enhancement for dmadev |

Checks

Context Check Description
ci/checkpatch success coding style OK

Commit Message

David Marchand Feb. 10, 2025, 5:44 p.m. UTC
Rather than use an intermediate variable, allow use of * to dereference
a trace point argument.
Update dmadev traces accordingly (and adjust the emitter type).

Signed-off-by: David Marchand <david.marchand@redhat.com>
---
Changes since v2:
- split this change out of patch 2, as it required updating CTF metadata
  fixup,

---
 lib/dmadev/rte_dmadev_trace_fp.h      | 12 +++------
 lib/eal/common/eal_common_trace_ctf.c | 35 ++++++++++++++++++---------
 2 files changed, 27 insertions(+), 20 deletions(-)
  

Comments

Sunil Kumar Kori Feb. 11, 2025, 8:44 a.m. UTC | #1
> diff --git a/lib/eal/common/eal_common_trace_ctf.c
> b/lib/eal/common/eal_common_trace_ctf.c
> index 04c4f71462..3e4228ee7f 100644
> --- a/lib/eal/common/eal_common_trace_ctf.c
> +++ b/lib/eal/common/eal_common_trace_ctf.c
> @@ -373,6 +373,11 @@ rte_trace_metadata_dump(FILE *f)
> 
>  char *trace_metadata_fixup_field(const char *field)  {
> +	static const char * const tokens[] = {
> +		".",
> +		"->",
> +		"*",
> +	};
As this patch is intended to support dereferencing operation but as a side effect it applies to multiplication operator too.
Hence for A * B, field is generated like A___B (one extra underscore). So IMO, multiplication string shouldn't be used.

>  	const char *ctf_reserved_words[] = {
>  		"align",
>  		"event",

> 2.48.1
  
David Marchand Feb. 11, 2025, 9:53 a.m. UTC | #2
On Tue, Feb 11, 2025 at 9:44 AM Sunil Kumar Kori <skori@marvell.com> wrote:
>
> > diff --git a/lib/eal/common/eal_common_trace_ctf.c
> > b/lib/eal/common/eal_common_trace_ctf.c
> > index 04c4f71462..3e4228ee7f 100644
> > --- a/lib/eal/common/eal_common_trace_ctf.c
> > +++ b/lib/eal/common/eal_common_trace_ctf.c
> > @@ -373,6 +373,11 @@ rte_trace_metadata_dump(FILE *f)
> >
> >  char *trace_metadata_fixup_field(const char *field)  {
> > +     static const char * const tokens[] = {
> > +             ".",
> > +             "->",
> > +             "*",
> > +     };
> As this patch is intended to support dereferencing operation but as a side effect it applies to multiplication operator too.

Support for multiplication helps with the next patch too, when passing
an array size as a blob length.

> Hence for A * B, field is generated like A___B (one extra underscore). So IMO, multiplication string shouldn't be used.

I am not following the consequence.. why should it be prevented?
  
Sunil Kumar Kori Feb. 12, 2025, 5:08 a.m. UTC | #3
> On Tue, Feb 11, 2025 at 9:44 AM Sunil Kumar Kori <skori@marvell.com>
> wrote:
> >
> > > diff --git a/lib/eal/common/eal_common_trace_ctf.c
> > > b/lib/eal/common/eal_common_trace_ctf.c
> > > index 04c4f71462..3e4228ee7f 100644
> > > --- a/lib/eal/common/eal_common_trace_ctf.c
> > > +++ b/lib/eal/common/eal_common_trace_ctf.c
> > > @@ -373,6 +373,11 @@ rte_trace_metadata_dump(FILE *f)
> > >
> > >  char *trace_metadata_fixup_field(const char *field)  {
> > > +     static const char * const tokens[] = {
> > > +             ".",
> > > +             "->",
> > > +             "*",
> > > +     };
> > As this patch is intended to support dereferencing operation but as a side
> effect it applies to multiplication operator too.
> 
> Support for multiplication helps with the next patch too, when passing an
> array size as a blob length.
> 
> > Hence for A * B, field is generated like A___B (one extra underscore). So
> IMO, multiplication string shouldn't be used.
> 
> I am not following the consequence.. why should it be prevented?
As such there is no consequence on functionality. It's just about readability.
For example, num_entries * size will result in num_entries___size which actually
not representing that this is used to size. Instead tot_size = num_entries * size and
then using tot_size clearly specifies that it is the total size of array. 
> 
> 
> --
> David Marchand
  

Patch

diff --git a/lib/dmadev/rte_dmadev_trace_fp.h b/lib/dmadev/rte_dmadev_trace_fp.h
index f5b96838bc..4950f58cd2 100644
--- a/lib/dmadev/rte_dmadev_trace_fp.h
+++ b/lib/dmadev/rte_dmadev_trace_fp.h
@@ -37,10 +37,9 @@  RTE_TRACE_POINT_FP(
 	enum rte_dma_vchan_status __status = 0;
 	status = &__status;
 #endif /* _RTE_TRACE_POINT_REGISTER_H_ */
-	int vchan_status = *status;
 	rte_trace_point_emit_i16(dev_id);
 	rte_trace_point_emit_u16(vchan);
-	rte_trace_point_emit_int(vchan_status);
+	rte_trace_point_emit_int(*status);
 	rte_trace_point_emit_int(ret);
 )
 
@@ -107,13 +106,11 @@  RTE_TRACE_POINT_FP(
 	last_idx = &__last_idx;
 	has_error = &__has_error;
 #endif /* _RTE_TRACE_POINT_REGISTER_H_ */
-	int has_error_val = *has_error;
-	int last_idx_val = *last_idx;
 	rte_trace_point_emit_i16(dev_id);
 	rte_trace_point_emit_u16(vchan);
 	rte_trace_point_emit_u16(nb_cpls);
-	rte_trace_point_emit_int(last_idx_val);
-	rte_trace_point_emit_int(has_error_val);
+	rte_trace_point_emit_u16(*last_idx);
+	rte_trace_point_emit_u8(*has_error);
 	rte_trace_point_emit_u16(ret);
 )
 
@@ -126,11 +123,10 @@  RTE_TRACE_POINT_FP(
 	uint16_t __last_idx = 0;
 	last_idx = &__last_idx;
 #endif /* _RTE_TRACE_POINT_REGISTER_H_ */
-	int last_idx_val = *last_idx;
 	rte_trace_point_emit_i16(dev_id);
 	rte_trace_point_emit_u16(vchan);
 	rte_trace_point_emit_u16(nb_cpls);
-	rte_trace_point_emit_int(last_idx_val);
+	rte_trace_point_emit_u16(*last_idx);
 	rte_trace_point_emit_ptr(status);
 	rte_trace_point_emit_u16(ret);
 )
diff --git a/lib/eal/common/eal_common_trace_ctf.c b/lib/eal/common/eal_common_trace_ctf.c
index 04c4f71462..3e4228ee7f 100644
--- a/lib/eal/common/eal_common_trace_ctf.c
+++ b/lib/eal/common/eal_common_trace_ctf.c
@@ -373,6 +373,11 @@  rte_trace_metadata_dump(FILE *f)
 
 char *trace_metadata_fixup_field(const char *field)
 {
+	static const char * const tokens[] = {
+		".",
+		"->",
+		"*",
+	};
 	const char *ctf_reserved_words[] = {
 		"align",
 		"event",
@@ -390,23 +395,29 @@  char *trace_metadata_fixup_field(const char *field)
 		return out;
 	}
 
+	for (i = 0; i < RTE_DIM(tokens); i++) {
+		if (strstr(field, tokens[i]) == NULL)
+			continue;
+		goto fixup;
+	}
+
 	/* nothing to replace, return early */
-	if (strstr(field, ".") == NULL && strstr(field, "->") == NULL)
-		return NULL;
+	return NULL;
 
+fixup:
 	out = strdup(field);
 	if (out == NULL)
 		return NULL;
-	p = out;
-	while ((p = strstr(p, ".")) != NULL) {
-		p[0] = '_';
-		p++;
-	}
-	p = out;
-	while ((p = strstr(p, "->")) != NULL) {
-		p[0] = '_';
-		p++;
-		memmove(p, p + 1, strlen(p));
+	for (i = 0; i < RTE_DIM(tokens); i++) {
+		p = out;
+		while ((p = strstr(p, tokens[i])) != NULL) {
+			p[0] = '_';
+			p++;
+			if (strlen(tokens[i]) != 1) {
+				memmove(p, p + (strlen(tokens[i]) - 1),
+					strlen(p) - (strlen(tokens[i]) - 2));
+			}
+		}
 	}
 	return out;
 }