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    SubjectRe: [PATCH v13 01/16] perf record: Introduce thread affinity and mmap masks
    Em Mon, Jan 31, 2022 at 07:03:12PM -0300, Arnaldo Carvalho de Melo escreveu:
    > 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);

    Make that nr_bits, sigh :-\

    > 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

    --

    - Arnaldo

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