Re: [PATCH v13 01/16] perf record: Introduce thread affinity and mmap masks

[Arnaldo Carvalho de Melo <acme@kernel.org>]

Em Mon, Jan 31, 2022 at 06:00:31PM -0300, Arnaldo Carvalho de Melo escreveu:
> Em Mon, Jan 17, 2022 at 09:34:21PM +0300, Alexey Bayduraev escreveu:
> > Introduce affinity and mmap thread masks. Thread affinity mask
> > defines CPUs that a thread is allowed to run on. Thread maps
> > mask defines mmap data buffers the thread serves to stream
> > profiling data from.
> > 
> > Acked-by: Andi Kleen <ak@linux.intel.com>
> > Acked-by: Namhyung Kim <namhyung@gmail.com>
> > Reviewed-by: Riccardo Mancini <rickyman7@gmail.com>
> > Tested-by: Riccardo Mancini <rickyman7@gmail.com>
> > Signed-off-by: Alexey Bayduraev <alexey.v.bayduraev@linux.intel.com>
> 
> Some simplifications I added here while reviewing this patchkit:
> 
> diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
> index 41998f2140cd5119..53b88c8600624237 100644
> --- a/tools/perf/builtin-record.c
> +++ b/tools/perf/builtin-record.c
> @@ -2213,35 +2213,33 @@ static int record__parse_affinity(const struct option *opt, const char *str, int
>  
>  static int record__mmap_cpu_mask_alloc(struct mmap_cpu_mask *mask, int nr_bits)
>  {
> -	mask->nbits = nr_bits;
>  	mask->bits = bitmap_zalloc(mask->nbits);
>  	if (!mask->bits)
>  		return -ENOMEM;
>  
> +	mask->nbits = nr_bits;
>  	return 0;


Interesting, building it at this point in the patchkit didn't uncover
the bug I introduced, only later when this gets used I got the compiler
error and applied this on top:

diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index 53b88c8600624237..6b0e506df20c002a 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -2213,7 +2213,7 @@ static int record__parse_affinity(const struct option *opt, const char *str, int
 
 static int record__mmap_cpu_mask_alloc(struct mmap_cpu_mask *mask, int nr_bits)
 {
-	mask->bits = bitmap_zalloc(mask->nbits);
+	mask->bits = bitmap_zalloc(nbits);
 	if (!mask->bits)
 		return -ENOMEM;
 

>  }
>  
>  static void record__mmap_cpu_mask_free(struct mmap_cpu_mask *mask)
>  {
>  	bitmap_free(mask->bits);
> +	mask->bits = NULL;
>  	mask->nbits = 0;
>  }
>  
>  static int record__thread_mask_alloc(struct thread_mask *mask, int nr_bits)
>  {
> -	int ret;
> +	int ret = record__mmap_cpu_mask_alloc(&mask->maps, nr_bits);
>  
> -	ret = record__mmap_cpu_mask_alloc(&mask->maps, nr_bits);
>  	if (ret) {
>  		mask->affinity.bits = NULL;
>  		return ret;
>  	}
>  
>  	ret = record__mmap_cpu_mask_alloc(&mask->affinity, nr_bits);
> -	if (ret) {
> +	if (ret)
>  		record__mmap_cpu_mask_free(&mask->maps);
> -		mask->maps.bits = NULL;
> -	}
>  
>  	return ret;
>  }
> @@ -2733,18 +2731,14 @@ struct option *record_options = __record_options;
>  
>  static void record__mmap_cpu_mask_init(struct mmap_cpu_mask *mask, struct perf_cpu_map *cpus)
>  {
> -	int c;
> -
> -	for (c = 0; c < cpus->nr; c++)
> +	for (int c = 0; c < cpus->nr; c++)
>  		set_bit(cpus->map[c].cpu, mask->bits);
>  }
>  
>  static void record__free_thread_masks(struct record *rec, int nr_threads)
>  {
> -	int t;
> -
>  	if (rec->thread_masks)
> -		for (t = 0; t < nr_threads; t++)
> +		for (int t = 0; t < nr_threads; t++)
>  			record__thread_mask_free(&rec->thread_masks[t]);
>  
>  	zfree(&rec->thread_masks);
> @@ -2752,7 +2746,7 @@ static void record__free_thread_masks(struct record *rec, int nr_threads)
>  
>  static int record__alloc_thread_masks(struct record *rec, int nr_threads, int nr_bits)
>  {
> -	int t, ret;
> +	int ret;
>  
>  	rec->thread_masks = zalloc(nr_threads * sizeof(*(rec->thread_masks)));
>  	if (!rec->thread_masks) {
> @@ -2760,7 +2754,7 @@ static int record__alloc_thread_masks(struct record *rec, int nr_threads, int nr
>  		return -ENOMEM;
>  	}
>  
> -	for (t = 0; t < nr_threads; t++) {
> +	for (int t = 0; t < nr_threads; t++) {
>  		ret = record__thread_mask_alloc(&rec->thread_masks[t], nr_bits);
>  		if (ret) {
>  			pr_err("Failed to allocate thread masks[%d]\n", t);
> @@ -2778,9 +2772,7 @@ static int record__alloc_thread_masks(struct record *rec, int nr_threads, int nr
>  
>  static int record__init_thread_default_masks(struct record *rec, struct perf_cpu_map *cpus)
>  {
> -	int ret;
> -
> -	ret = record__alloc_thread_masks(rec, 1, cpu__max_cpu().cpu);
> +	int ret = record__alloc_thread_masks(rec, 1, cpu__max_cpu().cpu);
>  	if (ret)
>  		return ret;
>  
> 
> 
> > ---
> >  tools/perf/builtin-record.c | 123 ++++++++++++++++++++++++++++++++++++
> >  1 file changed, 123 insertions(+)
> > 
> > diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
> > index bb716c953d02..41998f2140cd 100644
> > --- a/tools/perf/builtin-record.c
> > +++ b/tools/perf/builtin-record.c
> > @@ -87,6 +87,11 @@ struct switch_output {
> >  	int		 cur_file;
> >  };
> >  
> > +struct thread_mask {
> > +	struct mmap_cpu_mask	maps;
> > +	struct mmap_cpu_mask	affinity;
> > +};
> > +
> >  struct record {
> >  	struct perf_tool	tool;
> >  	struct record_opts	opts;
> > @@ -112,6 +117,8 @@ struct record {
> >  	struct mmap_cpu_mask	affinity_mask;
> >  	unsigned long		output_max_size;	/* = 0: unlimited */
> >  	struct perf_debuginfod	debuginfod;
> > +	int			nr_threads;
> > +	struct thread_mask	*thread_masks;
> >  };
> >  
> >  static volatile int done;
> > @@ -2204,6 +2211,47 @@ static int record__parse_affinity(const struct option *opt, const char *str, int
> >  	return 0;
> >  }
> >  
> > +static int record__mmap_cpu_mask_alloc(struct mmap_cpu_mask *mask, int nr_bits)
> > +{
> > +	mask->nbits = nr_bits;
> > +	mask->bits = bitmap_zalloc(mask->nbits);
> > +	if (!mask->bits)
> > +		return -ENOMEM;
> > +
> > +	return 0;
> > +}
> > +
> > +static void record__mmap_cpu_mask_free(struct mmap_cpu_mask *mask)
> > +{
> > +	bitmap_free(mask->bits);
> > +	mask->nbits = 0;
> > +}
> > +
> > +static int record__thread_mask_alloc(struct thread_mask *mask, int nr_bits)
> > +{
> > +	int ret;
> > +
> > +	ret = record__mmap_cpu_mask_alloc(&mask->maps, nr_bits);
> > +	if (ret) {
> > +		mask->affinity.bits = NULL;
> > +		return ret;
> > +	}
> > +
> > +	ret = record__mmap_cpu_mask_alloc(&mask->affinity, nr_bits);
> > +	if (ret) {
> > +		record__mmap_cpu_mask_free(&mask->maps);
> > +		mask->maps.bits = NULL;
> > +	}
> > +
> > +	return ret;
> > +}
> > +
> > +static void record__thread_mask_free(struct thread_mask *mask)
> > +{
> > +	record__mmap_cpu_mask_free(&mask->maps);
> > +	record__mmap_cpu_mask_free(&mask->affinity);
> > +}
> > +
> >  static int parse_output_max_size(const struct option *opt,
> >  				 const char *str, int unset)
> >  {
> > @@ -2683,6 +2731,73 @@ static struct option __record_options[] = {
> >  
> >  struct option *record_options = __record_options;
> >  
> > +static void record__mmap_cpu_mask_init(struct mmap_cpu_mask *mask, struct perf_cpu_map *cpus)
> > +{
> > +	int c;
> > +
> > +	for (c = 0; c < cpus->nr; c++)
> > +		set_bit(cpus->map[c].cpu, mask->bits);
> > +}
> > +
> > +static void record__free_thread_masks(struct record *rec, int nr_threads)
> > +{
> > +	int t;
> > +
> > +	if (rec->thread_masks)
> > +		for (t = 0; t < nr_threads; t++)
> > +			record__thread_mask_free(&rec->thread_masks[t]);
> > +
> > +	zfree(&rec->thread_masks);
> > +}
> > +
> > +static int record__alloc_thread_masks(struct record *rec, int nr_threads, int nr_bits)
> > +{
> > +	int t, ret;
> > +
> > +	rec->thread_masks = zalloc(nr_threads * sizeof(*(rec->thread_masks)));
> > +	if (!rec->thread_masks) {
> > +		pr_err("Failed to allocate thread masks\n");
> > +		return -ENOMEM;
> > +	}
> > +
> > +	for (t = 0; t < nr_threads; t++) {
> > +		ret = record__thread_mask_alloc(&rec->thread_masks[t], nr_bits);
> > +		if (ret) {
> > +			pr_err("Failed to allocate thread masks[%d]\n", t);
> > +			goto out_free;
> > +		}
> > +	}
> > +
> > +	return 0;
> > +
> > +out_free:
> > +	record__free_thread_masks(rec, nr_threads);
> > +
> > +	return ret;
> > +}
> > +
> > +static int record__init_thread_default_masks(struct record *rec, struct perf_cpu_map *cpus)
> > +{
> > +	int ret;
> > +
> > +	ret = record__alloc_thread_masks(rec, 1, cpu__max_cpu().cpu);
> > +	if (ret)
> > +		return ret;
> > +
> > +	record__mmap_cpu_mask_init(&rec->thread_masks->maps, cpus);
> > +
> > +	rec->nr_threads = 1;
> > +
> > +	return 0;
> > +}
> > +
> > +static int record__init_thread_masks(struct record *rec)
> > +{
> > +	struct perf_cpu_map *cpus = rec->evlist->core.cpus;
> > +
> > +	return record__init_thread_default_masks(rec, cpus);
> > +}
> > +
> >  int cmd_record(int argc, const char **argv)
> >  {
> >  	int err;
> > @@ -2948,6 +3063,12 @@ int cmd_record(int argc, const char **argv)
> >  		goto out;
> >  	}
> >  
> > +	err = record__init_thread_masks(rec);
> > +	if (err) {
> > +		pr_err("Failed to initialize parallel data streaming masks\n");
> > +		goto out;
> > +	}
> > +
> >  	if (rec->opts.nr_cblocks > nr_cblocks_max)
> >  		rec->opts.nr_cblocks = nr_cblocks_max;
> >  	pr_debug("nr_cblocks: %d\n", rec->opts.nr_cblocks);
> > @@ -2966,6 +3087,8 @@ int cmd_record(int argc, const char **argv)
> >  	symbol__exit();
> >  	auxtrace_record__free(rec->itr);
> >  out_opts:
> > +	record__free_thread_masks(rec, rec->nr_threads);
> > +	rec->nr_threads = 0;
> >  	evlist__close_control(rec->opts.ctl_fd, rec->opts.ctl_fd_ack, &rec->opts.ctl_fd_close);
> >  	return err;
> >  }
> > -- 
> > 2.19.0
> 
> -- 
> 
> - Arnaldo

-- 

- Arnaldo