Re: [PATCH V7 05/25] perf record: Add basic AUX area tracing support

[Jiri Olsa <jolsa@redhat.com>]

On Tue, Mar 31, 2015 at 02:38:34PM +0300, Adrian Hunter wrote:
> Amend the perf record tool to read the
> AUX area tracing mmap and synthesize
> AUX area tracing events.
> 
> Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>

Acked-by: Jiri Olsa <jolsa@kernel.org>

> ---
>  tools/perf/builtin-record.c | 81 ++++++++++++++++++++++++++++++++++++++++++---
>  1 file changed, 77 insertions(+), 4 deletions(-)
> 
> diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
> index 18aad239..0de9432 100644
> --- a/tools/perf/builtin-record.c
> +++ b/tools/perf/builtin-record.c
> @@ -27,6 +27,7 @@
>  #include "util/cpumap.h"
>  #include "util/thread_map.h"
>  #include "util/data.h"
> +#include "util/auxtrace.h"
>  
>  #include <unistd.h>
>  #include <sched.h>
> @@ -38,6 +39,7 @@ struct record {
>  	struct record_opts	opts;
>  	u64			bytes_written;
>  	struct perf_data_file	file;
> +	struct auxtrace_record	*itr;
>  	struct perf_evlist	*evlist;
>  	struct perf_session	*session;
>  	const char		*progname;
> @@ -110,6 +112,44 @@ out:
>  	return rc;
>  }
>  
> +static int record__process_auxtrace(struct perf_tool *tool,
> +				    union perf_event *event, void *data1,
> +				    size_t len1, void *data2, size_t len2)
> +{
> +	struct record *rec = container_of(tool, struct record, tool);
> +	size_t padding;
> +	u8 pad[8] = {0};
> +
> +	/* event.auxtrace.size includes padding, see __auxtrace_mmap__read() */
> +	padding = (len1 + len2) & 7;
> +	if (padding)
> +		padding = 8 - padding;
> +
> +	record__write(rec, event, event->header.size);
> +	record__write(rec, data1, len1);
> +	if (len2)
> +		record__write(rec, data2, len2);
> +	record__write(rec, &pad, padding);
> +
> +	return 0;
> +}
> +
> +static int record__auxtrace_mmap_read(struct record *rec,
> +				      struct auxtrace_mmap *mm)
> +{
> +	int ret;
> +
> +	ret = auxtrace_mmap__read(mm, rec->itr, &rec->tool,
> +				  record__process_auxtrace);
> +	if (ret < 0)
> +		return ret;
> +
> +	if (ret)
> +		rec->samples++;
> +
> +	return 0;
> +}
> +
>  static volatile int done = 0;
>  static volatile int signr = -1;
>  static volatile int child_finished = 0;
> @@ -169,13 +209,15 @@ try_again:
>  		goto out;
>  	}
>  
> -	if (perf_evlist__mmap(evlist, opts->mmap_pages, false) < 0) {
> +	if (perf_evlist__mmap_ex(evlist, opts->mmap_pages, false,
> +				 opts->auxtrace_mmap_pages, false) < 0) {
>  		if (errno == EPERM) {
>  			pr_err("Permission error mapping pages.\n"
>  			       "Consider increasing "
>  			       "/proc/sys/kernel/perf_event_mlock_kb,\n"
>  			       "or try again with a smaller value of -m/--mmap_pages.\n"
> -			       "(current value: %u)\n", opts->mmap_pages);
> +			       "(current value: %u,%u)\n",
> +			       opts->mmap_pages, opts->auxtrace_mmap_pages);
>  			rc = -errno;
>  		} else {
>  			pr_err("failed to mmap with %d (%s)\n", errno,
> @@ -270,12 +312,20 @@ static int record__mmap_read_all(struct record *rec)
>  	int rc = 0;
>  
>  	for (i = 0; i < rec->evlist->nr_mmaps; i++) {
> +		struct auxtrace_mmap *mm = &rec->evlist->mmap[i].auxtrace_mmap;
> +
>  		if (rec->evlist->mmap[i].base) {
>  			if (record__mmap_read(rec, i) != 0) {
>  				rc = -1;
>  				goto out;
>  			}
>  		}
> +
> +		if (mm->base &&
> +		    record__auxtrace_mmap_read(rec, mm) != 0) {
> +			rc = -1;
> +			goto out;
> +		}
>  	}
>  
>  	/*
> @@ -305,6 +355,9 @@ static void record__init_features(struct record *rec)
>  
>  	if (!rec->opts.branch_stack)
>  		perf_header__clear_feat(&session->header, HEADER_BRANCH_STACK);
> +
> +	if (!rec->opts.full_auxtrace)
> +		perf_header__clear_feat(&session->header, HEADER_AUXTRACE);
>  }
>  
>  static volatile int workload_exec_errno;
> @@ -421,6 +474,13 @@ static int __cmd_record(struct record *rec, int argc, const char **argv)
>  		}
>  	}
>  
> +	if (rec->opts.full_auxtrace) {
> +		err = perf_event__synthesize_auxtrace_info(rec->itr, tool,
> +					session, process_synthesized_event);
> +		if (err)
> +			goto out_delete_session;
> +	}
> +
>  	err = perf_event__synthesize_kernel_mmap(tool, process_synthesized_event,
>  						 machine);
>  	if (err < 0)
> @@ -553,7 +613,7 @@ out_child:
>  	if (!err && !quiet) {
>  		char samples[128];
>  
> -		if (rec->samples)
> +		if (rec->samples && !rec->opts.full_auxtrace)
>  			scnprintf(samples, sizeof(samples),
>  				  " (%" PRIu64 " samples)", rec->samples);
>  		else
> @@ -849,7 +909,7 @@ struct option *record_options = __record_options;
>  
>  int cmd_record(int argc, const char **argv, const char *prefix __maybe_unused)
>  {
> -	int err = -ENOMEM;
> +	int err;
>  	struct record *rec = &record;
>  	char errbuf[BUFSIZ];
>  
> @@ -870,6 +930,14 @@ int cmd_record(int argc, const char **argv, const char *prefix __maybe_unused)
>  		usage_with_options(record_usage, record_options);
>  	}
>  
> +	if (!rec->itr) {
> +		rec->itr = auxtrace_record__init(rec->evlist, &err);
> +		if (err)
> +			return err;
> +	}
> +
> +	err = -ENOMEM;
> +
>  	symbol__init(NULL);
>  
>  	if (symbol_conf.kptr_restrict)
> @@ -915,6 +983,10 @@ int cmd_record(int argc, const char **argv, const char *prefix __maybe_unused)
>  	if (perf_evlist__create_maps(rec->evlist, &rec->opts.target) < 0)
>  		usage_with_options(record_usage, record_options);
>  
> +	err = auxtrace_record__options(rec->itr, rec->evlist, &rec->opts);
> +	if (err)
> +		goto out_symbol_exit;
> +
>  	if (record_opts__config(&rec->opts)) {
>  		err = -EINVAL;
>  		goto out_symbol_exit;
> @@ -924,5 +996,6 @@ int cmd_record(int argc, const char **argv, const char *prefix __maybe_unused)
>  out_symbol_exit:
>  	perf_evlist__delete(rec->evlist);
>  	symbol__exit();
> +	auxtrace_record__free(rec->itr);
>  	return err;
>  }
> -- 
> 1.9.1
>