Re: [PATCH 4/4] perf session: Keep pointers to the vmlinux maps

[Masami Hiramatsu <mhiramat@redhat.com>]

Arnaldo Carvalho de Melo wrote:
> From: Arnaldo Carvalho de Melo <acme@redhat.com>
> 
> So that tools such as 'perf probe' don't have to lookup '[kernel.kallsyms]' but
> instead access them directly after perf_session__create_kernel_maps or
> map_groups__create_kernel_maps.


Looks good for me:-) Thanks.

Acked-by: Masami Hiramatsu <mhiramat@redhat.com>

> 
> Cc: Masami Hiramatsu <mhiramat@redhat.com>
> Cc: Frédéric Weisbecker <fweisbec@gmail.com>
> Cc: Mike Galbraith <efault@gmx.de>
> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
> Cc: Paul Mackerras <paulus@samba.org>
> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
> ---
>  tools/perf/builtin-probe.c |    4 +---
>  tools/perf/util/session.h  |    1 +
>  tools/perf/util/symbol.c   |   29 +++++++++++++----------------
>  3 files changed, 15 insertions(+), 19 deletions(-)
> 
> diff --git a/tools/perf/builtin-probe.c b/tools/perf/builtin-probe.c
> index c1e6774..ffdd3fe 100644
> --- a/tools/perf/builtin-probe.c
> +++ b/tools/perf/builtin-probe.c
> @@ -235,9 +235,7 @@ int cmd_probe(int argc, const char **argv, const char *prefix __used)
>  	session.psession = perf_session__new(NULL, O_WRONLY, false);
>  	if (session.psession == NULL)
>  		die("Failed to init perf_session.");
> -	session.kmap = map_groups__find_by_name(&session.psession->kmaps,
> -						MAP__FUNCTION,
> -						"[kernel.kallsyms]");
> +	session.kmap = session.psession->vmlinux_maps[MAP__FUNCTION];
>  	if (!session.kmap)
>  		die("Could not find kernel map.\n");
>  
> diff --git a/tools/perf/util/session.h b/tools/perf/util/session.h
> index 77c5ee2..8db37bb 100644
> --- a/tools/perf/util/session.h
> +++ b/tools/perf/util/session.h
> @@ -18,6 +18,7 @@ struct perf_session {
>  	struct map_groups	kmaps;
>  	struct rb_root		threads;
>  	struct thread		*last_match;
> +	struct map		*vmlinux_maps[MAP__NR_TYPES];
>  	struct events_stats	events_stats;
>  	unsigned long		event_total[PERF_RECORD_MAX];
>  	unsigned long		unknown_events;
> diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
> index 5dffcd1..e290429 100644
> --- a/tools/perf/util/symbol.c
> +++ b/tools/perf/util/symbol.c
> @@ -1662,7 +1662,7 @@ size_t dsos__fprintf_buildid(FILE *fp)
>  		__dsos__fprintf_buildid(&dsos__user, fp));
>  }
>  
> -static struct dso *dsos__create_kernel( const char *vmlinux)
> +static struct dso *dsos__create_kernel(const char *vmlinux)
>  {
>  	struct dso *kernel = dso__new(vmlinux ?: "[kernel.kallsyms]");
>  
> @@ -1691,29 +1691,26 @@ out_delete_kernel_dso:
>  	return NULL;
>  }
>  
> -static int map_groups__create_kernel_maps(struct map_groups *self, const char *vmlinux)
> +static int map_groups__create_kernel_maps(struct map_groups *self,
> +					  struct map *vmlinux_maps[MAP__NR_TYPES],
> +					  const char *vmlinux)
>  {
> -	struct map *functions, *variables;
>  	struct dso *kernel = dsos__create_kernel(vmlinux);
> +	enum map_type type;
>  
>  	if (kernel == NULL)
>  		return -1;
>  
> -	functions = map__new2(0, kernel, MAP__FUNCTION);
> -	if (functions == NULL)
> -		return -1;
> +	for (type = 0; type < MAP__NR_TYPES; ++type) {
> +		vmlinux_maps[type] = map__new2(0, kernel, type);
> +		if (vmlinux_maps[type] == NULL)
> +			return -1;
>  
> -	variables = map__new2(0, kernel, MAP__VARIABLE);
> -	if (variables == NULL) {
> -		map__delete(functions);
> -		return -1;
> +		vmlinux_maps[type]->map_ip =
> +			vmlinux_maps[type]->unmap_ip = identity__map_ip;
> +		map_groups__insert(self, vmlinux_maps[type]);
>  	}
>  
> -	functions->map_ip = functions->unmap_ip =
> -		variables->map_ip = variables->unmap_ip = identity__map_ip;
> -	map_groups__insert(self, functions);
> -	map_groups__insert(self, variables);
> -
>  	return 0;
>  }
>  
> @@ -1824,7 +1821,7 @@ out_free_comm_list:
>  
>  int perf_session__create_kernel_maps(struct perf_session *self)
>  {
> -	if (map_groups__create_kernel_maps(&self->kmaps,
> +	if (map_groups__create_kernel_maps(&self->kmaps, self->vmlinux_maps,
>  					   symbol_conf.vmlinux_name) < 0)
>  		return -1;
>  

-- 
Masami Hiramatsu

Software Engineer
Hitachi Computer Products (America), Inc.
Software Solutions Division

e-mail: mhiramat@redhat.com