From nobody Wed Apr 8 07:34:01 2026 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id D21CCC28D13 for ; Tue, 23 Aug 2022 02:59:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239464AbiHWC72 (ORCPT ); Mon, 22 Aug 2022 22:59:28 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52226 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239766AbiHWC7X (ORCPT ); Mon, 22 Aug 2022 22:59:23 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 50FAE3CBCD for ; Mon, 22 Aug 2022 19:59:22 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 868966125D for ; Tue, 23 Aug 2022 02:59:21 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id D5C34C433D6; Tue, 23 Aug 2022 02:59:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1661223561; bh=eVxcuH5ca3RnEh6lL1A4I8CCBLgAsX6Qf8tk1thKUkE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=e4A7Segh0gCQnI6Byvrv5yaWPQ036ANK2djxWZOJ/+4bYqoALpb4nz8rDGyhBIELA Dw5+5AUlh+rgS54weSswFCqaUfBiRz5ZaGBOLKGmQ1oW0NBij/SzbquaEibSTpTFtH wA4O8Ym/0hWfazj7XdmqULQXjI4WfqLGG1Ko/DgVhUQnqHXtEBlaiuCWQJUFA8JzbM XuHlhT10L3GxEnpKK6jjCJQdbounpyoIBajjxI0lBmnivjwYvn5n3FfbJ8irm/dXZj xd0svCPU/NpUOHxLXqIhvfMZGYwqF4L66Dc4e7eDiM59bNIMy38NPqqbOA2m6mhOzj ng4/Yi6IlJjUA== From: "Masami Hiramatsu (Google)" To: Steven Rostedt Cc: Tom Zanussi , Ingo Molnar , linux-kernel@vger.kernel.org Subject: [PATCH v3 2/3] tracing: Add .percent suffix option to histogram values Date: Tue, 23 Aug 2022 11:59:17 +0900 Message-Id: <166122355689.94548.10059318113254937350.stgit@devnote2> X-Mailer: git-send-email 2.25.1 In-Reply-To: <166122353724.94548.7395770385598120122.stgit@devnote2> References: <166122353724.94548.7395770385598120122.stgit@devnote2> User-Agent: StGit/0.19 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Masami Hiramatsu (Google) Add .percent suffix option to show the histogram values in percentage. This feature is useful when we need yo undersntand the overall trend for the histograms of large values. E.g. this shows the runtime percentage for each tasks. ------ # cd /sys/kernel/debug/tracing/ # echo hist:keys=3Dpid:vals=3Dhitcount,runtime.percent:sort=3Dpid > \ events/sched/sched_stat_runtime/trigger # sleep 10 # cat events/sched/sched_stat_runtime/hist # event histogram # # trigger info: hist:keys=3Dpid:vals=3Dhitcount,runtime.percent:sort=3Dpid= :size=3D2048 [active] # { pid: 8 } hitcount: 7 runtime (%): 4.14 { pid: 14 } hitcount: 5 runtime (%): 3.69 { pid: 16 } hitcount: 11 runtime (%): 3.41 { pid: 61 } hitcount: 41 runtime (%): 19.75 { pid: 65 } hitcount: 4 runtime (%): 1.48 { pid: 70 } hitcount: 6 runtime (%): 3.60 { pid: 72 } hitcount: 2 runtime (%): 1.10 { pid: 144 } hitcount: 10 runtime (%): 32.01 { pid: 151 } hitcount: 8 runtime (%): 22.66 { pid: 152 } hitcount: 2 runtime (%): 8.10 Totals: Hits: 96 Entries: 10 Dropped: 0 ----- Signed-off-by: Masami Hiramatsu (Google) --- Changes in v3: - Show "(%)" in the field name. - Return div0 error only if the value is not zero. - Simplify the print code with hist_trigger_print_val(). - Show hitcount percentage correctly. Changes in v2: - Use div64_*(). - Show an error when failing to calculate the percentage. --- kernel/trace/trace.c | 3 + kernel/trace/trace_events_hist.c | 107 ++++++++++++++++++++++++++++++++--= ---- 2 files changed, 92 insertions(+), 18 deletions(-) diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 27febd4ee33e..174c91ae957e 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -5700,7 +5700,8 @@ static const char readme_msg[] =3D "\t .syscall display a syscall id as a syscall name\n" "\t .log2 display log2 value rather than raw number\n" "\t .buckets=3Dsize display values in groups of size rather t= han raw number\n" - "\t .usecs display a common_timestamp in microseconds\n\n" + "\t .usecs display a common_timestamp in microseconds\n" + "\t .percent display a number of percentage value\n\n" "\t The 'pause' parameter can be used to pause an existing hist\n" "\t trigger or to start a hist trigger but not log any events\n" "\t until told to do so. 'continue' can be used to start or\n" diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_h= ist.c index fdf784620c28..d285a2d55f88 100644 --- a/kernel/trace/trace_events_hist.c +++ b/kernel/trace/trace_events_hist.c @@ -477,6 +477,7 @@ enum hist_field_flags { HIST_FIELD_FL_ALIAS =3D 1 << 16, HIST_FIELD_FL_BUCKET =3D 1 << 17, HIST_FIELD_FL_CONST =3D 1 << 18, + HIST_FIELD_FL_PERCENT =3D 1 << 19, }; =20 struct var_defs { @@ -1682,6 +1683,8 @@ static const char *get_hist_field_flags(struct hist_f= ield *hist_field) flags_str =3D "buckets"; else if (hist_field->flags & HIST_FIELD_FL_TIMESTAMP_USECS) flags_str =3D "usecs"; + else if (hist_field->flags & HIST_FIELD_FL_PERCENT) + flags_str =3D "percent"; =20 return flags_str; } @@ -2290,6 +2293,10 @@ parse_field(struct hist_trigger_data *hist_data, str= uct trace_event_file *file, if (ret || !(*buckets)) goto error; *flags |=3D HIST_FIELD_FL_BUCKET; + } else if (strncmp(modifier, "percent", 7) =3D=3D 0) { + if (*flags & (HIST_FIELD_FL_VAR | HIST_FIELD_FL_KEY)) + goto error; + *flags |=3D HIST_FIELD_FL_PERCENT; } else { error: hist_err(tr, HIST_ERR_BAD_FIELD_MODIFIER, errpos(modifier)); @@ -4254,8 +4261,13 @@ static int create_val_fields(struct hist_trigger_dat= a *hist_data, if (!field_str) break; =20 - if (strcmp(field_str, "hitcount") =3D=3D 0) + if (strncmp(field_str, "hitcount", 8) =3D=3D 0 && + (field_str[8] =3D=3D '.' || field_str[8] =3D=3D '\0')) { + if (strncmp(field_str + 8, ".percent", 8) =3D=3D 0) + hist_data->fields[HITCOUNT_IDX]->flags |=3D + HIST_FIELD_FL_PERCENT; continue; + } =20 ret =3D create_val_field(hist_data, j++, file, field_str); if (ret) @@ -5190,33 +5202,73 @@ static void hist_trigger_print_key(struct seq_file = *m, seq_puts(m, "}"); } =20 +/* Get the 100 times of the percentage of @val in @total */ +static inline unsigned int __get_percentage(u64 val, u64 total) +{ + if (!total) + goto div0; + + if (val < (U64_MAX / 10000)) + return (unsigned int)div64_ul(val * 10000, total); + + total =3D div64_u64(total, 10000); + if (!total) + goto div0; + + return (unsigned int)div64_ul(val, total); +div0: + return val ? UINT_MAX : 0; +} + +static void hist_trigger_print_val(struct seq_file *m, unsigned int idx, + const char *field_name, unsigned long flags, + u64 *totals, struct tracing_map_elt *elt) +{ + u64 val =3D tracing_map_read_sum(elt, idx); + unsigned int pc; + + if (flags & HIST_FIELD_FL_PERCENT) { + pc =3D __get_percentage(val, totals[idx]); + if (pc =3D=3D UINT_MAX) + seq_printf(m, " %s (%%):[ERROR]", field_name); + else + seq_printf(m, " %s (%%): %3u.%02u", field_name, + pc / 100, pc % 100); + } else if (flags & HIST_FIELD_FL_HEX) { + seq_printf(m, " %s: %10llx", field_name, val); + } else { + seq_printf(m, " %s: %10llu", field_name, val); + } +} + static void hist_trigger_entry_print(struct seq_file *m, struct hist_trigger_data *hist_data, + u64 *totals, void *key, struct tracing_map_elt *elt) { const char *field_name; - unsigned int i; + unsigned int i =3D HITCOUNT_IDX; + unsigned long flags; =20 hist_trigger_print_key(m, hist_data, key, elt); =20 - seq_printf(m, " hitcount: %10llu", - tracing_map_read_sum(elt, HITCOUNT_IDX)); + hist_trigger_print_val(m, i, "hitcount", 0, totals, elt); + + flags =3D hist_data->fields[i]->flags; + if (flags & HIST_FIELD_FL_PERCENT) + hist_trigger_print_val(m, i, " hitcount", + HIST_FIELD_FL_PERCENT, totals, elt); =20 for (i =3D 1; i < hist_data->n_vals; i++) { field_name =3D hist_field_name(hist_data->fields[i], 0); + flags =3D hist_data->fields[i]->flags; =20 - if (hist_data->fields[i]->flags & HIST_FIELD_FL_VAR || - hist_data->fields[i]->flags & HIST_FIELD_FL_EXPR) + if (flags & HIST_FIELD_FL_VAR || flags & HIST_FIELD_FL_EXPR) continue; =20 - if (hist_data->fields[i]->flags & HIST_FIELD_FL_HEX) { - seq_printf(m, " %s: %10llx", field_name, - tracing_map_read_sum(elt, i)); - } else { - seq_printf(m, " %s: %10llu", field_name, - tracing_map_read_sum(elt, i)); - } + seq_puts(m, " "); + hist_trigger_print_val(m, i, field_name, flags, totals, elt); } =20 print_actions(m, hist_data, elt); @@ -5229,7 +5281,8 @@ static int print_entries(struct seq_file *m, { struct tracing_map_sort_entry **sort_entries =3D NULL; struct tracing_map *map =3D hist_data->map; - int i, n_entries; + int i, j, n_entries; + u64 *totals =3D NULL; =20 n_entries =3D tracing_map_sort_entries(map, hist_data->sort_keys, hist_data->n_sort_keys, @@ -5237,11 +5290,29 @@ static int print_entries(struct seq_file *m, if (n_entries < 0) return n_entries; =20 + for (j =3D 0; j < hist_data->n_vals; j++) { + if (!(hist_data->fields[j]->flags & HIST_FIELD_FL_PERCENT)) + continue; + if (!totals) { + totals =3D kcalloc(hist_data->n_vals, sizeof(u64), + GFP_KERNEL); + if (!totals) { + n_entries =3D -ENOMEM; + goto out; + } + } + for (i =3D 0; i < n_entries; i++) + totals[j] +=3D tracing_map_read_sum( + sort_entries[i]->elt, j); + } + for (i =3D 0; i < n_entries; i++) - hist_trigger_entry_print(m, hist_data, + hist_trigger_entry_print(m, hist_data, totals, sort_entries[i]->key, sort_entries[i]->elt); =20 + kfree(totals); +out: tracing_map_destroy_sort_entries(sort_entries, n_entries); =20 return n_entries; @@ -5661,9 +5732,11 @@ static int event_hist_trigger_print(struct seq_file = *m, continue; } =20 - if (i =3D=3D HITCOUNT_IDX) + if (i =3D=3D HITCOUNT_IDX) { seq_puts(m, "hitcount"); - else { + if (field->flags & HIST_FIELD_FL_PERCENT) + seq_puts(m, ",hitcount.percent"); + } else { seq_puts(m, ","); hist_field_print(m, field); }