[v4,perf,bpf,06/15] perf, bpf: save bpf_prog_info in a rbtree in perf_env
diff mbox series

Message ID 20190226002019.3748539-7-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. 26, 2019, 12:20 a.m. UTC
bpf_prog_info contains information necessary to annotate bpf programs.
This patch saves bpf_prog_info for bpf programs loaded in the system.

Signed-off-by: Song Liu <songliubraving@fb.com>
---
 tools/perf/util/bpf-event.c | 32 +++++++++++++-
 tools/perf/util/bpf-event.h |  7 ++-
 tools/perf/util/env.c       | 85 +++++++++++++++++++++++++++++++++++++
 tools/perf/util/env.h       | 17 ++++++++
 4 files changed, 139 insertions(+), 2 deletions(-)

Comments

Jiri Olsa Feb. 27, 2019, 1:21 p.m. UTC | #1
On Mon, Feb 25, 2019 at 04:20:10PM -0800, Song Liu wrote:
> bpf_prog_info contains information necessary to annotate bpf programs.
> This patch saves bpf_prog_info for bpf programs loaded in the system.
> 
> Signed-off-by: Song Liu <songliubraving@fb.com>
> ---
>  tools/perf/util/bpf-event.c | 32 +++++++++++++-
>  tools/perf/util/bpf-event.h |  7 ++-
>  tools/perf/util/env.c       | 85 +++++++++++++++++++++++++++++++++++++
>  tools/perf/util/env.h       | 17 ++++++++
>  4 files changed, 139 insertions(+), 2 deletions(-)
> 
> diff --git a/tools/perf/util/bpf-event.c b/tools/perf/util/bpf-event.c
> index ff7ee149ec46..ce81b2c43a51 100644
> --- a/tools/perf/util/bpf-event.c
> +++ b/tools/perf/util/bpf-event.c
> @@ -10,6 +10,7 @@
>  #include "debug.h"
>  #include "symbol.h"
>  #include "machine.h"
> +#include "env.h"
>  #include "session.h"
>  
>  #define ptr_to_u64(ptr)    ((__u64)(unsigned long)(ptr))
> @@ -54,17 +55,28 @@ static int perf_event__synthesize_one_bpf_prog(struct perf_session *session,
>  	struct bpf_event *bpf_event = &event->bpf_event;
>  	struct bpf_prog_info_linear *info_linear;
>  	struct perf_tool *tool = session->tool;
> +	struct bpf_prog_info_node *info_node;
>  	struct bpf_prog_info *info;
>  	struct btf *btf = NULL;
>  	bool has_btf = false;
> +	struct perf_env *env;
>  	u32 sub_prog_cnt, i;
>  	int err = 0;
>  	u64 arrays;
>  
> +	/*
> +	 * for perf-record and perf-report use header.env;
> +	 * otherwise, use global perf_env.
> +	 */
> +	env = session->data ? &session->header.env : &perf_env;
> +
>  	arrays = 1UL << BPF_PROG_INFO_JITED_KSYMS;
>  	arrays |= 1UL << BPF_PROG_INFO_JITED_FUNC_LENS;
>  	arrays |= 1UL << BPF_PROG_INFO_FUNC_INFO;
>  	arrays |= 1UL << BPF_PROG_INFO_PROG_TAGS;
> +	arrays |= 1UL << BPF_PROG_INFO_JITED_INSNS;
> +	arrays |= 1UL << BPF_PROG_INFO_LINE_INFO;
> +	arrays |= 1UL << BPF_PROG_INFO_JITED_LINE_INFO;
>  
>  	info_linear = bpf_program__get_prog_info_linear(fd, arrays);
>  	if (IS_ERR_OR_NULL(info_linear)) {
> @@ -153,8 +165,8 @@ static int perf_event__synthesize_one_bpf_prog(struct perf_session *session,
>  						     machine, process);
>  	}
>  
> -	/* Synthesize PERF_RECORD_BPF_EVENT */
>  	if (opts->bpf_event) {
> +		/* Synthesize PERF_RECORD_BPF_EVENT */
>  		*bpf_event = (struct bpf_event){
>  			.header = {
>  				.type = PERF_RECORD_BPF_EVENT,
> @@ -167,6 +179,24 @@ static int perf_event__synthesize_one_bpf_prog(struct perf_session *session,
>  		memcpy(bpf_event->tag, info->tag, BPF_TAG_SIZE);
>  		memset((void *)event + event->header.size, 0, machine->id_hdr_size);
>  		event->header.size += machine->id_hdr_size;
> +
> +		/* save bpf_prog_info to env */

why do we save this to perf_env in here? we just
synthesize the same data as event, so report and
top will read it and fill perf_env again, right?

could you please explain the whole flow of the
bpf events and its respective data in perf_env
and put it into the changelog

> +		info_node = malloc(sizeof(struct bpf_prog_info_node));
> +
> +		/*
> +		 * Do not bail out for !info_node, as we still want to
> +		 * call  perf_tool__process_synth_event()

well, we are out of memory, so I dont think perf_tool__process_synth_event
will get too far.. also the perf_env data would be inconsistent with what
you store as event.. how can that work?

thanks,
jirka

> +		 */
> +		if (info_node) {
> +			info_node->info_linear = info_linear;
> +			perf_env__insert_bpf_prog_info(env, info_node);
> +			info_linear = NULL;
> +		}
> +

SNIP
Jiri Olsa Feb. 27, 2019, 1:21 p.m. UTC | #2
On Mon, Feb 25, 2019 at 04:20:10PM -0800, Song Liu wrote:

SNIP

> @@ -38,6 +116,12 @@ void perf_env__exit(struct perf_env *env)
>  	zfree(&env->memory_nodes);
>  }
>  
> +static void init_bpf_rb_trees(struct perf_env *env)
> +{
> +	env->bpf_progs.prog_infos = RB_ROOT;
> +	init_rwsem(&env->bpf_progs.lock);
> +}
> +
>  int perf_env__set_cmdline(struct perf_env *env, int argc, const char *argv[])
>  {
>  	int i;
> @@ -59,6 +143,7 @@ int perf_env__set_cmdline(struct perf_env *env, int argc, const char *argv[])
>  
>  	env->nr_cmdline = argc;
>  
> +	init_bpf_rb_trees(env);

this souldn't be in perf_env__set_cmdline,
it's there to set the cmdline

struct bpf_progs is first in perf_env that
needs other than zero initialization, so
I think we need to add perf_env__init function,
that will do that for all the paths that uses
perf_env


jirka
Jiri Olsa Feb. 27, 2019, 1:21 p.m. UTC | #3
On Mon, Feb 25, 2019 at 04:20:10PM -0800, Song Liu wrote:

SNIP

> diff --git a/tools/perf/util/env.h b/tools/perf/util/env.h
> index d01b8355f4ca..33ef4b2d2a29 100644
> --- a/tools/perf/util/env.h
> +++ b/tools/perf/util/env.h
> @@ -3,7 +3,9 @@
>  #define __PERF_ENV_H
>  
>  #include <linux/types.h>
> +#include <linux/rbtree.h>
>  #include "cpumap.h"
> +#include "rwsem.h"
>  
>  struct cpu_topology_map {
>  	int	socket_id;
> @@ -64,8 +66,19 @@ struct perf_env {
>  	struct memory_node	*memory_nodes;
>  	unsigned long long	 memory_bsize;
>  	u64                     clockid_res_ns;
> +
> +	/*
> +	 * bpf_info_lock protects bpf rbtrees. This is needed because the
> +	 * trees are accessed by different threads in perf-top
> +	 */
> +	struct {
> +		struct rw_semaphore	lock;
> +		struct rb_root		prog_infos;

could be just 'infos'                   ^^^^ is already in struct name


> +	} bpf_progs;
>  };
>  


jirka
Song Liu Feb. 27, 2019, 5:38 p.m. UTC | #4
> On Feb 27, 2019, at 5:21 AM, Jiri Olsa <jolsa@redhat.com> wrote:
> 
> On Mon, Feb 25, 2019 at 04:20:10PM -0800, Song Liu wrote:
>> bpf_prog_info contains information necessary to annotate bpf programs.
>> This patch saves bpf_prog_info for bpf programs loaded in the system.
>> 
>> Signed-off-by: Song Liu <songliubraving@fb.com>
>> ---
>> tools/perf/util/bpf-event.c | 32 +++++++++++++-
>> tools/perf/util/bpf-event.h |  7 ++-
>> tools/perf/util/env.c       | 85 +++++++++++++++++++++++++++++++++++++
>> tools/perf/util/env.h       | 17 ++++++++
>> 4 files changed, 139 insertions(+), 2 deletions(-)
>> 
>> diff --git a/tools/perf/util/bpf-event.c b/tools/perf/util/bpf-event.c
>> index ff7ee149ec46..ce81b2c43a51 100644
>> --- a/tools/perf/util/bpf-event.c
>> +++ b/tools/perf/util/bpf-event.c
>> @@ -10,6 +10,7 @@
>> #include "debug.h"
>> #include "symbol.h"
>> #include "machine.h"
>> +#include "env.h"
>> #include "session.h"
>> 
>> #define ptr_to_u64(ptr)    ((__u64)(unsigned long)(ptr))
>> @@ -54,17 +55,28 @@ static int perf_event__synthesize_one_bpf_prog(struct perf_session *session,
>> 	struct bpf_event *bpf_event = &event->bpf_event;
>> 	struct bpf_prog_info_linear *info_linear;
>> 	struct perf_tool *tool = session->tool;
>> +	struct bpf_prog_info_node *info_node;
>> 	struct bpf_prog_info *info;
>> 	struct btf *btf = NULL;
>> 	bool has_btf = false;
>> +	struct perf_env *env;
>> 	u32 sub_prog_cnt, i;
>> 	int err = 0;
>> 	u64 arrays;
>> 
>> +	/*
>> +	 * for perf-record and perf-report use header.env;
>> +	 * otherwise, use global perf_env.
>> +	 */
>> +	env = session->data ? &session->header.env : &perf_env;
>> +
>> 	arrays = 1UL << BPF_PROG_INFO_JITED_KSYMS;
>> 	arrays |= 1UL << BPF_PROG_INFO_JITED_FUNC_LENS;
>> 	arrays |= 1UL << BPF_PROG_INFO_FUNC_INFO;
>> 	arrays |= 1UL << BPF_PROG_INFO_PROG_TAGS;
>> +	arrays |= 1UL << BPF_PROG_INFO_JITED_INSNS;
>> +	arrays |= 1UL << BPF_PROG_INFO_LINE_INFO;
>> +	arrays |= 1UL << BPF_PROG_INFO_JITED_LINE_INFO;
>> 
>> 	info_linear = bpf_program__get_prog_info_linear(fd, arrays);
>> 	if (IS_ERR_OR_NULL(info_linear)) {
>> @@ -153,8 +165,8 @@ static int perf_event__synthesize_one_bpf_prog(struct perf_session *session,
>> 						     machine, process);
>> 	}
>> 
>> -	/* Synthesize PERF_RECORD_BPF_EVENT */
>> 	if (opts->bpf_event) {
>> +		/* Synthesize PERF_RECORD_BPF_EVENT */
>> 		*bpf_event = (struct bpf_event){
>> 			.header = {
>> 				.type = PERF_RECORD_BPF_EVENT,
>> @@ -167,6 +179,24 @@ static int perf_event__synthesize_one_bpf_prog(struct perf_session *session,
>> 		memcpy(bpf_event->tag, info->tag, BPF_TAG_SIZE);
>> 		memset((void *)event + event->header.size, 0, machine->id_hdr_size);
>> 		event->header.size += machine->id_hdr_size;
>> +
>> +		/* save bpf_prog_info to env */
> 
> why do we save this to perf_env in here? we just
> synthesize the same data as event, so report and
> top will read it and fill perf_env again, right?

The synthesized events are same as PERF_RECORD_BPF_EVENT
PROG_LOAD. We need to process them and fill perf_env as
soon as we get PROG_LOAD. Otherwise, the program might 
unload before we process them. 

> 
> could you please explain the whole flow of the
> bpf events and its respective data in perf_env
> and put it into the changelog

I will add more information to the change log. 

> 
>> +		info_node = malloc(sizeof(struct bpf_prog_info_node));
>> +
>> +		/*
>> +		 * Do not bail out for !info_node, as we still want to
>> +		 * call  perf_tool__process_synth_event()
> 
> well, we are out of memory, so I dont think perf_tool__process_synth_event
> will get too far.. also the perf_env data would be inconsistent with what
> you store as event.. how can that work?

It is OK we have PERF_RECORD_BPF_EVENT but not related
bpf_prog_info and btf. The perf.data file will show 
a BPF program was loaded, but we won't be able to do 
annotation. Does this make sense?

Thanks,
Song

> 
> thanks,
> jirka
> 
>> +		 */
>> +		if (info_node) {
>> +			info_node->info_linear = info_linear;
>> +			perf_env__insert_bpf_prog_info(env, info_node);
>> +			info_linear = NULL;
>> +		}
>> +
> 
> SNIP

Patch
diff mbox series

diff --git a/tools/perf/util/bpf-event.c b/tools/perf/util/bpf-event.c
index ff7ee149ec46..ce81b2c43a51 100644
--- a/tools/perf/util/bpf-event.c
+++ b/tools/perf/util/bpf-event.c
@@ -10,6 +10,7 @@ 
 #include "debug.h"
 #include "symbol.h"
 #include "machine.h"
+#include "env.h"
 #include "session.h"
 
 #define ptr_to_u64(ptr)    ((__u64)(unsigned long)(ptr))
@@ -54,17 +55,28 @@  static int perf_event__synthesize_one_bpf_prog(struct perf_session *session,
 	struct bpf_event *bpf_event = &event->bpf_event;
 	struct bpf_prog_info_linear *info_linear;
 	struct perf_tool *tool = session->tool;
+	struct bpf_prog_info_node *info_node;
 	struct bpf_prog_info *info;
 	struct btf *btf = NULL;
 	bool has_btf = false;
+	struct perf_env *env;
 	u32 sub_prog_cnt, i;
 	int err = 0;
 	u64 arrays;
 
+	/*
+	 * for perf-record and perf-report use header.env;
+	 * otherwise, use global perf_env.
+	 */
+	env = session->data ? &session->header.env : &perf_env;
+
 	arrays = 1UL << BPF_PROG_INFO_JITED_KSYMS;
 	arrays |= 1UL << BPF_PROG_INFO_JITED_FUNC_LENS;
 	arrays |= 1UL << BPF_PROG_INFO_FUNC_INFO;
 	arrays |= 1UL << BPF_PROG_INFO_PROG_TAGS;
+	arrays |= 1UL << BPF_PROG_INFO_JITED_INSNS;
+	arrays |= 1UL << BPF_PROG_INFO_LINE_INFO;
+	arrays |= 1UL << BPF_PROG_INFO_JITED_LINE_INFO;
 
 	info_linear = bpf_program__get_prog_info_linear(fd, arrays);
 	if (IS_ERR_OR_NULL(info_linear)) {
@@ -153,8 +165,8 @@  static int perf_event__synthesize_one_bpf_prog(struct perf_session *session,
 						     machine, process);
 	}
 
-	/* Synthesize PERF_RECORD_BPF_EVENT */
 	if (opts->bpf_event) {
+		/* Synthesize PERF_RECORD_BPF_EVENT */
 		*bpf_event = (struct bpf_event){
 			.header = {
 				.type = PERF_RECORD_BPF_EVENT,
@@ -167,6 +179,24 @@  static int perf_event__synthesize_one_bpf_prog(struct perf_session *session,
 		memcpy(bpf_event->tag, info->tag, BPF_TAG_SIZE);
 		memset((void *)event + event->header.size, 0, machine->id_hdr_size);
 		event->header.size += machine->id_hdr_size;
+
+		/* save bpf_prog_info to env */
+		info_node = malloc(sizeof(struct bpf_prog_info_node));
+
+		/*
+		 * Do not bail out for !info_node, as we still want to
+		 * call  perf_tool__process_synth_event()
+		 */
+		if (info_node) {
+			info_node->info_linear = info_linear;
+			perf_env__insert_bpf_prog_info(env, info_node);
+			info_linear = NULL;
+		}
+
+		/*
+		 * process after saving bpf_prog_info to env, so that
+		 * required information is ready for look up
+		 */
 		err = perf_tool__process_synth_event(tool, event,
 						     machine, process);
 	}
diff --git a/tools/perf/util/bpf-event.h b/tools/perf/util/bpf-event.h
index 6698683612a7..fad932f7404f 100644
--- a/tools/perf/util/bpf-event.h
+++ b/tools/perf/util/bpf-event.h
@@ -3,14 +3,19 @@ 
 #define __PERF_BPF_EVENT_H
 
 #include <linux/compiler.h>
+#include <linux/rbtree.h>
 #include "event.h"
 
 struct machine;
 union perf_event;
 struct perf_sample;
-struct perf_tool;
 struct record_opts;
 
+struct bpf_prog_info_node {
+	struct bpf_prog_info_linear	*info_linear;
+	struct rb_node			rb_node;
+};
+
 #ifdef HAVE_LIBBPF_SUPPORT
 int machine__process_bpf_event(struct machine *machine, union perf_event *event,
 			       struct perf_sample *sample);
diff --git a/tools/perf/util/env.c b/tools/perf/util/env.c
index 4c23779e271a..650c14ad7e9b 100644
--- a/tools/perf/util/env.c
+++ b/tools/perf/util/env.c
@@ -3,15 +3,93 @@ 
 #include "env.h"
 #include "sane_ctype.h"
 #include "util.h"
+#include "bpf-event.h"
 #include <errno.h>
 #include <sys/utsname.h>
+#include <bpf/libbpf.h>
 
 struct perf_env perf_env;
 
+void perf_env__insert_bpf_prog_info(struct perf_env *env,
+				    struct bpf_prog_info_node *info_node)
+{
+	__u32 prog_id = info_node->info_linear->info.id;
+	struct bpf_prog_info_node *node;
+	struct rb_node *parent = NULL;
+	struct rb_node **p;
+
+	down_write(&env->bpf_progs.lock);
+	p = &env->bpf_progs.prog_infos.rb_node;
+
+	while (*p != NULL) {
+		parent = *p;
+		node = rb_entry(parent, struct bpf_prog_info_node, rb_node);
+		if (prog_id < node->info_linear->info.id) {
+			p = &(*p)->rb_left;
+		} else if (prog_id > node->info_linear->info.id) {
+			p = &(*p)->rb_right;
+		} else {
+			pr_debug("duplicated bpf prog info %u\n", prog_id);
+			goto out;
+		}
+	}
+
+	rb_link_node(&info_node->rb_node, parent, p);
+	rb_insert_color(&info_node->rb_node, &env->bpf_progs.prog_infos);
+out:
+	up_write(&env->bpf_progs.lock);
+}
+
+struct bpf_prog_info_node *perf_env__find_bpf_prog_info(struct perf_env *env,
+							__u32 prog_id)
+{
+	struct bpf_prog_info_node *node = NULL;
+	struct rb_node *n;
+
+	down_read(&env->bpf_progs.lock);
+	n = env->bpf_progs.prog_infos.rb_node;
+
+	while (n) {
+		node = rb_entry(n, struct bpf_prog_info_node, rb_node);
+		if (prog_id < node->info_linear->info.id)
+			n = n->rb_left;
+		else if (prog_id > node->info_linear->info.id)
+			n = n->rb_right;
+		else
+			break;
+	}
+
+	up_read(&env->bpf_progs.lock);
+	return node;
+}
+
+/* purge data in bpf_prog_infos tree */
+static void perf_env__purge_bpf(struct perf_env *env)
+{
+	struct rb_root *root;
+	struct rb_node *next;
+
+	down_write(&env->bpf_progs.lock);
+
+	root = &env->bpf_progs.prog_infos;
+	next = rb_first(root);
+
+	while (next) {
+		struct bpf_prog_info_node *node;
+
+		node = rb_entry(next, struct bpf_prog_info_node, rb_node);
+		next = rb_next(&node->rb_node);
+		rb_erase_init(&node->rb_node, root);
+		free(node);
+	}
+	up_write(&env->bpf_progs.lock);
+}
+
 void perf_env__exit(struct perf_env *env)
 {
 	int i;
 
+	perf_env__purge_bpf(env);
 	zfree(&env->hostname);
 	zfree(&env->os_release);
 	zfree(&env->version);
@@ -38,6 +116,12 @@  void perf_env__exit(struct perf_env *env)
 	zfree(&env->memory_nodes);
 }
 
+static void init_bpf_rb_trees(struct perf_env *env)
+{
+	env->bpf_progs.prog_infos = RB_ROOT;
+	init_rwsem(&env->bpf_progs.lock);
+}
+
 int perf_env__set_cmdline(struct perf_env *env, int argc, const char *argv[])
 {
 	int i;
@@ -59,6 +143,7 @@  int perf_env__set_cmdline(struct perf_env *env, int argc, const char *argv[])
 
 	env->nr_cmdline = argc;
 
+	init_bpf_rb_trees(env);
 	return 0;
 out_free:
 	zfree(&env->cmdline_argv);
diff --git a/tools/perf/util/env.h b/tools/perf/util/env.h
index d01b8355f4ca..33ef4b2d2a29 100644
--- a/tools/perf/util/env.h
+++ b/tools/perf/util/env.h
@@ -3,7 +3,9 @@ 
 #define __PERF_ENV_H
 
 #include <linux/types.h>
+#include <linux/rbtree.h>
 #include "cpumap.h"
+#include "rwsem.h"
 
 struct cpu_topology_map {
 	int	socket_id;
@@ -64,8 +66,19 @@  struct perf_env {
 	struct memory_node	*memory_nodes;
 	unsigned long long	 memory_bsize;
 	u64                     clockid_res_ns;
+
+	/*
+	 * bpf_info_lock protects bpf rbtrees. This is needed because the
+	 * trees are accessed by different threads in perf-top
+	 */
+	struct {
+		struct rw_semaphore	lock;
+		struct rb_root		prog_infos;
+	} bpf_progs;
 };
 
+struct bpf_prog_info_node;
+
 extern struct perf_env perf_env;
 
 void perf_env__exit(struct perf_env *env);
@@ -80,4 +93,8 @@  const char *perf_env__arch(struct perf_env *env);
 const char *perf_env__raw_arch(struct perf_env *env);
 int perf_env__nr_cpus_avail(struct perf_env *env);
 
+void perf_env__insert_bpf_prog_info(struct perf_env *env,
+				    struct bpf_prog_info_node *info_node);
+struct bpf_prog_info_node *perf_env__find_bpf_prog_info(struct perf_env *env,
+							__u32 prog_id);
 #endif /* __PERF_ENV_H */