Re: [PATCH v2 1/2] perf hist: Deduplicate cmp/sort/collapse code

Namhyung Kim
2025-01-15T01:07:04Z

On Mon, Jan 13, 2025 at 02:34:14PM +0100, Dmitry Vyukov wrote:
> Application of cmp/sort/collapse fmt callbacks is duplicated 6 times.
> Factor it into a common helper function. NFC.
>
> Signed-off-by: Dmitry Vyukov <dvyukov@google.com>
> Cc: Namhyung Kim <namhyung@kernel.org>
> Cc: Ian Rogers <irogers@google.com>
> Cc: linux-perf-users@vger.kernel.org
> Cc: linux-kernel@vger.kernel.org
>
> ---
>
> Changes in v2:
> - add perf_hpp_fmt_cmp_t typedef to util/hist.h
> - use the typedef for perf_hpp_fmt::{cmp,collapse,sort}
> ---
> tools/perf/util/hist.c | 103 +++++++++++++++++------------------------
> tools/perf/util/hist.h | 14 +++---
> 2 files changed, 49 insertions(+), 68 deletions(-)
>
> diff --git a/tools/perf/util/hist.c b/tools/perf/util/hist.c
> index fff1345658016..a4b8ec3805565 100644
> --- a/tools/perf/util/hist.c
> +++ b/tools/perf/util/hist.c
> @@ -32,6 +32,9 @@
> #include <linux/time64.h>
> #include <linux/zalloc.h>
>
> +static int64_t hist_entry__cmp(struct hist_entry *left, struct hist_entry *right);
> +static int64_t hist_entry__collapse(struct hist_entry *left, struct hist_entry *right);
> +
> static bool hists__filter_entry_by_dso(struct hists *hists,
> struct hist_entry *he);
> static bool hists__filter_entry_by_thread(struct hists *hists,
> @@ -1292,19 +1295,26 @@ int hist_entry_iter__add(struct hist_entry_iter *iter, struct addr_location *al,
> return err;
> }
>
> -int64_t
> -hist_entry__cmp(struct hist_entry *left, struct hist_entry *right)
> +static int64_t
> +hist_entry__cmp_impl(struct perf_hpp_list *hpp_list, struct hist_entry *left,
> + struct hist_entry *right, unsigned long fn_offset,
> + bool ignore_dynamic, bool ignore_skipped)

Maybe it's a matter of tastes, but I think it could be simpler like
below.

> {
> struct hists *hists = left->hists;
> struct perf_hpp_fmt *fmt;
> int64_t cmp = 0;
> + perf_hpp_fmt_cmp_t fn;

perf_hpp_fmt_cmp_t *fn;

>
> - hists__for_each_sort_list(hists, fmt) {
> - if (perf_hpp__is_dynamic_entry(fmt) &&
> + perf_hpp_list__for_each_sort_list(hpp_list, fmt) {
> + if (ignore_dynamic && perf_hpp__is_dynamic_entry(fmt) &&
> !perf_hpp__defined_dynamic_entry(fmt, hists))
> continue;
>
> - cmp = fmt->cmp(fmt, left, right);
> + if (ignore_skipped && perf_hpp__should_skip(fmt, hists))
> + continue;
> +
> + fn = *(perf_hpp_fmt_cmp_t *)(((char *)fmt) + fn_offset);
> + cmp = fn(fmt, left, right);

fn = (void *)fmt + fn_offset;
cmp = (*fn)(fmt, left, right);

Otherwise, looks good to me.

Thanks,
Namhyung

> if (cmp)
> break;
> }
> @@ -1313,23 +1323,33 @@ hist_entry__cmp(struct hist_entry *left, struct hist_entry *right)
> }
>
> int64_t
> -hist_entry__collapse(struct hist_entry *left, struct hist_entry *right)
> +hist_entry__cmp(struct hist_entry *left, struct hist_entry *right)
> {
> - struct hists *hists = left->hists;
> - struct perf_hpp_fmt *fmt;
> - int64_t cmp = 0;
> + return hist_entry__cmp_impl(left->hists->hpp_list, left, right,
> + offsetof(struct perf_hpp_fmt, cmp), true, false);
> +}
>
> - hists__for_each_sort_list(hists, fmt) {
> - if (perf_hpp__is_dynamic_entry(fmt) &&
> - !perf_hpp__defined_dynamic_entry(fmt, hists))
> - continue;
> +static int64_t
> +hist_entry__sort(struct hist_entry *left, struct hist_entry *right)
> +{
> + return hist_entry__cmp_impl(left->hists->hpp_list, left, right,
> + offsetof(struct perf_hpp_fmt, sort), false, true);
> +}
>
> - cmp = fmt->collapse(fmt, left, right);
> - if (cmp)
> - break;
> - }
> +int64_t
> +hist_entry__collapse(struct hist_entry *left, struct hist_entry *right)
> +{
> + return hist_entry__cmp_impl(left->hists->hpp_list, left, right,
> + offsetof(struct perf_hpp_fmt, collapse), true, false);
> +}
>
> - return cmp;
> +static int64_t
> +hist_entry__collapse_hierarchy(struct perf_hpp_list *hpp_list,
> + struct hist_entry *left,
> + struct hist_entry *right)
> +{
> + return hist_entry__cmp_impl(hpp_list, left, right,
> + offsetof(struct perf_hpp_fmt, collapse), false, false);
> }
>
> void hist_entry__delete(struct hist_entry *he)
> @@ -1503,14 +1523,7 @@ static struct hist_entry *hierarchy_insert_entry(struct hists *hists,
> while (*p != NULL) {
> parent = *p;
> iter = rb_entry(parent, struct hist_entry, rb_node_in);
> -
> - cmp = 0;
> - perf_hpp_list__for_each_sort_list(hpp_list, fmt) {
> - cmp = fmt->collapse(fmt, iter, he);
> - if (cmp)
> - break;
> - }
> -
> + cmp = hist_entry__collapse_hierarchy(hpp_list, iter, he);
> if (!cmp) {
> he_stat__add_stat(&iter->stat, &he->stat);
> return iter;
> @@ -1730,24 +1743,6 @@ int hists__collapse_resort(struct hists *hists, struct ui_progress *prog)
> return 0;
> }
>
> -static int64_t hist_entry__sort(struct hist_entry *a, struct hist_entry *b)
> -{
> - struct hists *hists = a->hists;
> - struct perf_hpp_fmt *fmt;
> - int64_t cmp = 0;
> -
> - hists__for_each_sort_list(hists, fmt) {
> - if (perf_hpp__should_skip(fmt, a->hists))
> - continue;
> -
> - cmp = fmt->sort(fmt, a, b);
> - if (cmp)
> - break;
> - }
> -
> - return cmp;
> -}
> -
> static void hists__reset_filter_stats(struct hists *hists)
> {
> hists->nr_non_filtered_entries = 0;
> @@ -2449,21 +2444,15 @@ static struct hist_entry *add_dummy_hierarchy_entry(struct hists *hists,
> struct rb_node **p;
> struct rb_node *parent = NULL;
> struct hist_entry *he;
> - struct perf_hpp_fmt *fmt;
> bool leftmost = true;
>
> p = &root->rb_root.rb_node;
> while (*p != NULL) {
> - int64_t cmp = 0;
> + int64_t cmp;
>
> parent = *p;
> he = rb_entry(parent, struct hist_entry, rb_node_in);
> -
> - perf_hpp_list__for_each_sort_list(he->hpp_list, fmt) {
> - cmp = fmt->collapse(fmt, he, pair);
> - if (cmp)
> - break;
> - }
> + cmp = hist_entry__collapse_hierarchy(he->hpp_list, he, pair);
> if (!cmp)
> goto out;
>
> @@ -2521,16 +2510,10 @@ static struct hist_entry *hists__find_hierarchy_entry(struct rb_root_cached *roo
>
> while (n) {
> struct hist_entry *iter;
> - struct perf_hpp_fmt *fmt;
> - int64_t cmp = 0;
> + int64_t cmp;
>
> iter = rb_entry(n, struct hist_entry, rb_node_in);
> - perf_hpp_list__for_each_sort_list(he->hpp_list, fmt) {
> - cmp = fmt->collapse(fmt, iter, he);
> - if (cmp)
> - break;
> - }
> -
> + cmp = hist_entry__collapse_hierarchy(he->hpp_list, iter, he);
> if (cmp < 0)
> n = n->rb_left;
> else if (cmp > 0)
> diff --git a/tools/perf/util/hist.h b/tools/perf/util/hist.h
> index 1131056924d9c..46c8373e31465 100644
> --- a/tools/perf/util/hist.h
> +++ b/tools/perf/util/hist.h
> @@ -342,8 +342,6 @@ int hist_entry_iter__add(struct hist_entry_iter *iter, struct addr_location *al,
> struct perf_hpp;
> struct perf_hpp_fmt;
>
> -int64_t hist_entry__cmp(struct hist_entry *left, struct hist_entry *right);
> -int64_t hist_entry__collapse(struct hist_entry *left, struct hist_entry *right);
> int hist_entry__transaction_len(void);
> int hist_entry__sort_snprintf(struct hist_entry *he, char *bf, size_t size,
> struct hists *hists);
> @@ -452,6 +450,9 @@ struct perf_hpp {
> bool skip;
> };
>
> +typedef int64_t (*perf_hpp_fmt_cmp_t)(
> + struct perf_hpp_fmt *, struct hist_entry *, struct hist_entry *);
> +
> struct perf_hpp_fmt {
> const char *name;
> int (*header)(struct perf_hpp_fmt *fmt, struct perf_hpp *hpp,
> @@ -463,12 +464,9 @@ struct perf_hpp_fmt {
> struct hist_entry *he);
> int (*entry)(struct perf_hpp_fmt *fmt, struct perf_hpp *hpp,
> struct hist_entry *he);
> - int64_t (*cmp)(struct perf_hpp_fmt *fmt,
> - struct hist_entry *a, struct hist_entry *b);
> - int64_t (*collapse)(struct perf_hpp_fmt *fmt,
> - struct hist_entry *a, struct hist_entry *b);
> - int64_t (*sort)(struct perf_hpp_fmt *fmt,
> - struct hist_entry *a, struct hist_entry *b);
> + perf_hpp_fmt_cmp_t cmp;
> + perf_hpp_fmt_cmp_t collapse;
> + perf_hpp_fmt_cmp_t sort;
> bool (*equal)(struct perf_hpp_fmt *a, struct perf_hpp_fmt *b);
> void (*free)(struct perf_hpp_fmt *fmt);
>
> --
> 2.47.1.688.g23fc6f90ad-goog
>