Re: [PATCH v7 perf,bpf 07/15] perf, bpf: save bpf_prog_info information as headers to perf.data

[Song Liu]

> On Mar 11, 2019, at 10:56 AM, Jiri Olsa <jolsa@xxxxxxxxxx> wrote:
> 
> On Thu, Mar 07, 2019 at 09:58:02AM -0800, Song Liu wrote:
>> This patch enables perf-record to save bpf_prog_info information as
>> headers to perf.data. A new header type HEADER_BPF_PROG_INFO is
>> introduced for this data.
>> 
>> Signed-off-by: Song Liu <songliubraving@xxxxxx>
>> ---
>> tools/perf/util/header.c | 145 ++++++++++++++++++++++++++++++++++++++-
>> tools/perf/util/header.h |   1 +
>> 2 files changed, 145 insertions(+), 1 deletion(-)
>> 
>> diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c
>> index 4b88de5e9192..f0708188211e 100644
>> --- a/tools/perf/util/header.c
>> +++ b/tools/perf/util/header.c
>> @@ -18,6 +18,7 @@
>> #include <sys/utsname.h>
>> #include <linux/time64.h>
>> #include <dirent.h>
>> +#include <bpf/libbpf.h>
>> 
>> #include "evlist.h"
>> #include "evsel.h"
>> @@ -39,6 +40,7 @@
>> #include "tool.h"
>> #include "time-utils.h"
>> #include "units.h"
>> +#include "bpf-event.h"
>> 
>> #include "sane_ctype.h"
>> 
>> @@ -1074,6 +1076,54 @@ static int write_clockid(struct feat_fd *ff,
>> 			sizeof(ff->ph->env.clockid_res_ns));
>> }
>> 
>> +static int write_bpf_prog_info(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.lock);
>> +
>> +	root = &env->bpf_progs.infos;
>> +	next = rb_first(root);
>> +	while (next) {
>> +		++count;
>> +		next = rb_next(next);
>> +	}
> 
> sry I did not se this before, but why you don't keep program count
> in perf_env::bpf_progs::infos_cnt ?
> 
> jirka

Good idea... I didn't think about this carefully. Will fix in next 
version. 

Thanks,
Song