[v3,perf,bpf,08/11] perf, bpf: save btf information as headers to perf.data
diff mbox series

Message ID 20190215215354.3114006-9-songliubraving@fb.com
State Changes Requested
Delegated to: BPF Maintainers
Headers show
Series
  • perf annotation of BPF programs
Related show

Commit Message

Song Liu Feb. 15, 2019, 9:53 p.m. UTC
This patch enables perf-record to save btf information as headers to
perf.data A new header type HEADER_BTF is introduced for this data.

Signed-off-by: Song Liu <songliubraving@fb.com>
---
 tools/perf/util/header.c | 99 +++++++++++++++++++++++++++++++++++++++-
 tools/perf/util/header.h |  1 +
 2 files changed, 99 insertions(+), 1 deletion(-)

Comments

Namhyung Kim Feb. 17, 2019, 2:58 p.m. UTC | #1
Hi,

On Sat, Feb 16, 2019 at 6:55 AM Song Liu <songliubraving@fb.com> wrote:
>
> This patch enables perf-record to save btf information as headers to
> perf.data A new header type HEADER_BTF is introduced for this data.
>
> Signed-off-by: Song Liu <songliubraving@fb.com>
> ---

[SNIP]
> +static void print_btf(struct feat_fd *ff, FILE *fp)
> +{
> +       struct perf_env *env = &ff->ph->env;
> +       struct rb_root *root;
> +       struct rb_node *next;
> +
> +       down_read(&env->bpf_progs.bpf_info_lock);
> +
> +       root = &env->bpf_progs.btfs;
> +       next = rb_first(root);
> +
> +       while (next) {
> +               struct btf_node *node;
> +
> +               node = rb_entry(next, struct btf_node, rb_node);
> +               next = rb_next(&node->rb_node);
> +               fprintf(fp, "# bpf_prog_info of id %u\n", node->id);

How about saying it's "btf" info?

Thanks,
Namhyung


> +       }
> +
> +       up_read(&env->bpf_progs.bpf_info_lock);
> +}
Jiri Olsa Feb. 17, 2019, 11:05 p.m. UTC | #2
On Fri, Feb 15, 2019 at 01:53:51PM -0800, Song Liu wrote:

SNIP

>  struct header_print_data {
> diff --git a/tools/perf/util/header.h b/tools/perf/util/header.h
> index 0785c91b4c3a..ba51d8e43c53 100644
> --- a/tools/perf/util/header.h
> +++ b/tools/perf/util/header.h
> @@ -40,6 +40,7 @@ enum {
>  	HEADER_MEM_TOPOLOGY,
>  	HEADER_CLOCKID,
>  	HEADER_BPF_PROG_INFO,
> +	HEADER_BTF,

hu, could we maybe prefix all the bpf related features with BPF_ ?

jirka

>  	HEADER_LAST_FEATURE,
>  	HEADER_FEAT_BITS	= 256,
>  };
> -- 
> 2.17.1
>
Jiri Olsa Feb. 17, 2019, 11:06 p.m. UTC | #3
On Fri, Feb 15, 2019 at 01:53:51PM -0800, Song Liu wrote:
> This patch enables perf-record to save btf information as headers to
> perf.data A new header type HEADER_BTF is introduced for this data.
> 
> Signed-off-by: Song Liu <songliubraving@fb.com>
> ---
>  tools/perf/util/header.c | 99 +++++++++++++++++++++++++++++++++++++++-
>  tools/perf/util/header.h |  1 +
>  2 files changed, 99 insertions(+), 1 deletion(-)
> 
> diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c
> index 0889ad797940..2de4f4e9b590 100644
> --- a/tools/perf/util/header.c
> +++ b/tools/perf/util/header.c
> @@ -1127,6 +1127,45 @@ static int write_bpf_prog_info(struct feat_fd *ff,
>  	return ret;
>  }
>  
> +static int write_btf(struct feat_fd *ff,
> +		     struct perf_evlist *evlist __maybe_unused)
> +{
> +	struct perf_env *env = &ff->ph->env;
> +	struct rb_root *root;
> +	struct rb_node *next;
> +	u32 count = 0;
> +	int ret;
> +
> +	down_read(&env->bpf_progs.bpf_info_lock);
> +
> +	root = &env->bpf_progs.btfs;
> +	next = rb_first(root);
> +	while (next) {
> +		++count;
> +		next = rb_next(next);
> +	}
> +
> +	ret = do_write(ff, &count, sizeof(count));
> +
> +	if (ret < 0)
> +		goto out;
> +
> +	next = rb_first(root);
> +	while (next) {
> +		struct btf_node *node;
> +
> +		node = rb_entry(next, struct btf_node, rb_node);
> +		next = rb_next(&node->rb_node);
> +		ret = do_write(ff, node,
> +			       sizeof(struct btf_node) + node->data_size);

hm, you write the whole struct btf_node with struct rb_node? why?

thanks,
jirka
Jiri Olsa Feb. 17, 2019, 11:06 p.m. UTC | #4
On Fri, Feb 15, 2019 at 01:53:51PM -0800, Song Liu wrote:

SNIP

> +static int process_btf(struct feat_fd *ff, void *data __maybe_unused)
> +{
> +	struct perf_env *env = &ff->ph->env;
> +	u32 count, i;
> +
> +	if (do_read_u32(ff, &count))
> +		return -1;
> +
> +	down_write(&env->bpf_progs.bpf_info_lock);
> +
> +	for (i = 0; i < count; ++i) {
> +		struct btf_node btf_node;
> +		struct btf_node *node;
> +
> +		if (__do_read(ff, &btf_node, sizeof(struct btf_node)))
> +			return -1;
> +
> +		node = malloc(sizeof(struct btf_node) + btf_node.data_size);
> +		if (!node)
> +			return -1;
> +
> +		node->id = btf_node.id;
> +		node->data_size = btf_node.data_size;
> +
> +		if (__do_read(ff, node->data, btf_node.data_size)) {
> +			free(node);
> +			return -1;
> +		}

hows endianity swap handled got struct btf_node and data in here?

thanks,
jirka
Song Liu Feb. 19, 2019, 5:48 a.m. UTC | #5
> On Feb 17, 2019, at 3:06 PM, Jiri Olsa <jolsa@redhat.com> wrote:
> 
> On Fri, Feb 15, 2019 at 01:53:51PM -0800, Song Liu wrote:
> 
> SNIP
> 
>> +static int process_btf(struct feat_fd *ff, void *data __maybe_unused)
>> +{
>> +	struct perf_env *env = &ff->ph->env;
>> +	u32 count, i;
>> +
>> +	if (do_read_u32(ff, &count))
>> +		return -1;
>> +
>> +	down_write(&env->bpf_progs.bpf_info_lock);
>> +
>> +	for (i = 0; i < count; ++i) {
>> +		struct btf_node btf_node;
>> +		struct btf_node *node;
>> +
>> +		if (__do_read(ff, &btf_node, sizeof(struct btf_node)))
>> +			return -1;
>> +
>> +		node = malloc(sizeof(struct btf_node) + btf_node.data_size);
>> +		if (!node)
>> +			return -1;
>> +
>> +		node->id = btf_node.id;
>> +		node->data_size = btf_node.data_size;
>> +
>> +		if (__do_read(ff, node->data, btf_node.data_size)) {
>> +			free(node);
>> +			return -1;
>> +		}
> 
> hows endianity swap handled got struct btf_node and data in here?
> 
> thanks,
> jirka

I thought about endianity at some point, but forgot about it. Let 
me see how to fix it. 

Thanks,
Song

Patch
diff mbox series

diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c
index 0889ad797940..2de4f4e9b590 100644
--- a/tools/perf/util/header.c
+++ b/tools/perf/util/header.c
@@ -1127,6 +1127,45 @@  static int write_bpf_prog_info(struct feat_fd *ff,
 	return ret;
 }
 
+static int write_btf(struct feat_fd *ff,
+		     struct perf_evlist *evlist __maybe_unused)
+{
+	struct perf_env *env = &ff->ph->env;
+	struct rb_root *root;
+	struct rb_node *next;
+	u32 count = 0;
+	int ret;
+
+	down_read(&env->bpf_progs.bpf_info_lock);
+
+	root = &env->bpf_progs.btfs;
+	next = rb_first(root);
+	while (next) {
+		++count;
+		next = rb_next(next);
+	}
+
+	ret = do_write(ff, &count, sizeof(count));
+
+	if (ret < 0)
+		goto out;
+
+	next = rb_first(root);
+	while (next) {
+		struct btf_node *node;
+
+		node = rb_entry(next, struct btf_node, rb_node);
+		next = rb_next(&node->rb_node);
+		ret = do_write(ff, node,
+			       sizeof(struct btf_node) + node->data_size);
+		if (ret < 0)
+			goto out;
+	}
+out:
+	up_read(&env->bpf_progs.bpf_info_lock);
+	return ret;
+}
+
 static int cpu_cache_level__sort(const void *a, const void *b)
 {
 	struct cpu_cache_level *cache_a = (struct cpu_cache_level *)a;
@@ -1630,6 +1669,28 @@  static void print_bpf_prog_info(struct feat_fd *ff, FILE *fp)
 	up_read(&env->bpf_progs.bpf_info_lock);
 }
 
+static void print_btf(struct feat_fd *ff, FILE *fp)
+{
+	struct perf_env *env = &ff->ph->env;
+	struct rb_root *root;
+	struct rb_node *next;
+
+	down_read(&env->bpf_progs.bpf_info_lock);
+
+	root = &env->bpf_progs.btfs;
+	next = rb_first(root);
+
+	while (next) {
+		struct btf_node *node;
+
+		node = rb_entry(next, struct btf_node, rb_node);
+		next = rb_next(&node->rb_node);
+		fprintf(fp, "# bpf_prog_info of id %u\n", node->id);
+	}
+
+	up_read(&env->bpf_progs.bpf_info_lock);
+}
+
 static void free_event_desc(struct perf_evsel *events)
 {
 	struct perf_evsel *evsel;
@@ -2725,6 +2786,41 @@  static int process_bpf_prog_info(struct feat_fd *ff,
 	return err;
 }
 
+static int process_btf(struct feat_fd *ff, void *data __maybe_unused)
+{
+	struct perf_env *env = &ff->ph->env;
+	u32 count, i;
+
+	if (do_read_u32(ff, &count))
+		return -1;
+
+	down_write(&env->bpf_progs.bpf_info_lock);
+
+	for (i = 0; i < count; ++i) {
+		struct btf_node btf_node;
+		struct btf_node *node;
+
+		if (__do_read(ff, &btf_node, sizeof(struct btf_node)))
+			return -1;
+
+		node = malloc(sizeof(struct btf_node) + btf_node.data_size);
+		if (!node)
+			return -1;
+
+		node->id = btf_node.id;
+		node->data_size = btf_node.data_size;
+
+		if (__do_read(ff, node->data, btf_node.data_size)) {
+			free(node);
+			return -1;
+		}
+		perf_env__insert_btf(env, node);
+	}
+
+	up_write(&env->bpf_progs.bpf_info_lock);
+	return 0;
+}
+
 struct feature_ops {
 	int (*write)(struct feat_fd *ff, struct perf_evlist *evlist);
 	void (*print)(struct feat_fd *ff, FILE *fp);
@@ -2785,7 +2881,8 @@  static const struct feature_ops feat_ops[HEADER_LAST_FEATURE] = {
 	FEAT_OPR(SAMPLE_TIME,	sample_time,	false),
 	FEAT_OPR(MEM_TOPOLOGY,	mem_topology,	true),
 	FEAT_OPR(CLOCKID,       clockid,        false),
-	FEAT_OPR(BPF_PROG_INFO, bpf_prog_info,  false)
+	FEAT_OPR(BPF_PROG_INFO, bpf_prog_info,  false),
+	FEAT_OPR(BTF,           btf,            false)
 };
 
 struct header_print_data {
diff --git a/tools/perf/util/header.h b/tools/perf/util/header.h
index 0785c91b4c3a..ba51d8e43c53 100644
--- a/tools/perf/util/header.h
+++ b/tools/perf/util/header.h
@@ -40,6 +40,7 @@  enum {
 	HEADER_MEM_TOPOLOGY,
 	HEADER_CLOCKID,
 	HEADER_BPF_PROG_INFO,
+	HEADER_BTF,
 	HEADER_LAST_FEATURE,
 	HEADER_FEAT_BITS	= 256,
 };