From nobody Wed Dec 17 12:45:06 2025 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 053EFC4167B for ; Mon, 27 Nov 2023 22:14:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234282AbjK0WN4 (ORCPT ); Mon, 27 Nov 2023 17:13:56 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44164 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233856AbjK0WNH (ORCPT ); Mon, 27 Nov 2023 17:13:07 -0500 Received: from mail-yw1-x114a.google.com (mail-yw1-x114a.google.com [IPv6:2607:f8b0:4864:20::114a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id ADAC91FD0 for ; Mon, 27 Nov 2023 14:10:47 -0800 (PST) Received: by mail-yw1-x114a.google.com with SMTP id 00721157ae682-5cfd2325a06so25319297b3.1 for ; Mon, 27 Nov 2023 14:10:47 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1701123046; x=1701727846; darn=vger.kernel.org; h=to:from:subject:references:mime-version:message-id:in-reply-to:date :from:to:cc:subject:date:message-id:reply-to; bh=yaMvGQIwm952jjWrCT4ml8Z5CScyNCbVZIlwZUsveHY=; b=ywACG4KMs88cV+79pEgY2uXws6Euw7Nivo1JVrOcvGlIKuI7FxhGkjWHa4qWY5jyL6 Dz/9S3/DzsRpb/uBVVBC4VIprncInyvdgZ9SwI9cZGx3C9qojpwe1JmbqhIWuxM0z4pf hRDyCJ5b1qcsV+I800vcHp2Qj9L138inb3OJJsCjwsLvp4BgUAk2y6HWCAcJQLF+CTc+ y4Rq1WWbAzAwhFHb0tt6q7OBJh7Dx4Wx1A58NMn7z9jSr5sf6hCzU0LDVija7igzjwSb NbpNNtLtbKhbQ8v/cUnSqGfbQUbGezECm+9OHiiR5cNpd47OGsMk4yHc9ZX+m+wtHvH6 pzAA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1701123046; x=1701727846; h=to:from:subject:references:mime-version:message-id:in-reply-to:date :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=yaMvGQIwm952jjWrCT4ml8Z5CScyNCbVZIlwZUsveHY=; b=Uq1XV0UTaR6x5BqnGeAK6CcfniJvdZFELvgSWUpzXnN+785tQA2Y34BaWVZvxXDBnZ rdEhaLSL6EY4UyPkvOQ+AtcgrpvVrhWrwDrHDCh4Ykt2kcchTXhLIRrgZmOihX86noxN 1TBow03ZJTtSVaBrmAV4VKTqUxluuJIPuP6qNZ1A9QE8vX43Mo4EjxQFQEe6bRUY2YbF OkhDQE8eqTIWX0KxDWULHPDQuLqdlP3Jht7DrSKo3v2qLdYQwUWcH1X/y8ZnisWRYO18 IH9san6kBfmqqaPF/uyyvnH5zofxziksH/odMHJjLacfMhJm5I55oRSWDyMmoGbRRgFJ R8gw== X-Gm-Message-State: AOJu0YyGJXgwYFLNPhmvXBv1ZFeNkn9JWplaH8BgQOABqw+nM1f93APQ 13R2CK1h+RuiGFstSsPmnpxSCUyWZucl X-Google-Smtp-Source: AGHT+IFAm1HXp+h/967s2xgHudQu1AnZOIoJDXbUhGY2ujJKKHQkk0EH9mNMrPYCM0Fvp72b885dHCsCa6Jp X-Received: from irogers.svl.corp.google.com ([2620:15c:2a3:200:829:6e77:9093:f39b]) (user=irogers job=sendgmr) by 2002:a05:690c:3301:b0:5c9:6d54:de9e with SMTP id fj1-20020a05690c330100b005c96d54de9emr400964ywb.10.1701123046429; Mon, 27 Nov 2023 14:10:46 -0800 (PST) Date: Mon, 27 Nov 2023 14:08:48 -0800 In-Reply-To: <20231127220902.1315692-1-irogers@google.com> Message-Id: <20231127220902.1315692-37-irogers@google.com> Mime-Version: 1.0 References: <20231127220902.1315692-1-irogers@google.com> X-Mailer: git-send-email 2.43.0.rc1.413.gea7ed67945-goog Subject: [PATCH v5 36/50] perf threads: Switch from rbtree to hashmap From: Ian Rogers To: Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Mark Rutland , Alexander Shishkin , Jiri Olsa , Namhyung Kim , Ian Rogers , Adrian Hunter , Nick Terrell , Kan Liang , Andi Kleen , Kajol Jain , Athira Rajeev , Huacai Chen , Masami Hiramatsu , Vincent Whitchurch , "Steinar H. Gunderson" , Liam Howlett , Miguel Ojeda , Colin Ian King , Dmitrii Dolgov <9erthalion6@gmail.com>, Yang Jihong , Ming Wang , James Clark , K Prateek Nayak , Sean Christopherson , Leo Yan , Ravi Bangoria , German Gomez , Changbin Du , Paolo Bonzini , Li Dong , Sandipan Das , liuwenyu , linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, Guilherme Amadio Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" The rbtree provides a sorting on entries but this is unused. Switch to using hashmap for O(1) rather than O(log n) find/insert/remove complexity. Signed-off-by: Ian Rogers --- tools/perf/util/threads.c | 146 ++++++++++++-------------------------- tools/perf/util/threads.h | 6 +- 2 files changed, 47 insertions(+), 105 deletions(-) diff --git a/tools/perf/util/threads.c b/tools/perf/util/threads.c index d984ec939c7b..55923be53180 100644 --- a/tools/perf/util/threads.c +++ b/tools/perf/util/threads.c @@ -3,25 +3,30 @@ #include "machine.h" #include "thread.h" =20 -struct thread_rb_node { - struct rb_node rb_node; - struct thread *thread; -}; - static struct threads_table_entry *threads__table(struct threads *threads,= pid_t tid) { /* Cast it to handle tid =3D=3D -1 */ return &threads->table[(unsigned int)tid % THREADS__TABLE_SIZE]; } =20 +static size_t key_hash(long key, void *ctx __maybe_unused) +{ + /* The table lookup removes low bit entropy, but this is just ignored her= e. */ + return key; +} + +static bool key_equal(long key1, long key2, void *ctx __maybe_unused) +{ + return key1 =3D=3D key2; +} + void threads__init(struct threads *threads) { for (int i =3D 0; i < THREADS__TABLE_SIZE; i++) { struct threads_table_entry *table =3D &threads->table[i]; =20 - table->entries =3D RB_ROOT_CACHED; + hashmap__init(&table->shard, key_hash, key_equal, NULL); init_rwsem(&table->lock); - table->nr =3D 0; table->last_match =3D NULL; } } @@ -32,6 +37,7 @@ void threads__exit(struct threads *threads) for (int i =3D 0; i < THREADS__TABLE_SIZE; i++) { struct threads_table_entry *table =3D &threads->table[i]; =20 + hashmap__clear(&table->shard); exit_rwsem(&table->lock); } } @@ -44,7 +50,7 @@ size_t threads__nr(struct threads *threads) struct threads_table_entry *table =3D &threads->table[i]; =20 down_read(&table->lock); - nr +=3D table->nr; + nr +=3D hashmap__size(&table->shard); up_read(&table->lock); } return nr; @@ -86,28 +92,13 @@ static void threads_table_entry__set_last_match(struct = threads_table_entry *tabl struct thread *threads__find(struct threads *threads, pid_t tid) { struct threads_table_entry *table =3D threads__table(threads, tid); - struct rb_node **p; - struct thread *res =3D NULL; + struct thread *res; =20 down_read(&table->lock); res =3D __threads_table_entry__get_last_match(table, tid); - if (res) - return res; - - p =3D &table->entries.rb_root.rb_node; - while (*p !=3D NULL) { - struct rb_node *parent =3D *p; - struct thread *th =3D rb_entry(parent, struct thread_rb_node, rb_node)->= thread; - - if (thread__tid(th) =3D=3D tid) { - res =3D thread__get(th); - break; - } - - if (tid < thread__tid(th)) - p =3D &(*p)->rb_left; - else - p =3D &(*p)->rb_right; + if (!res) { + if (hashmap__find(&table->shard, tid, &res)) + res =3D thread__get(res); } up_read(&table->lock); if (res) @@ -118,49 +109,25 @@ struct thread *threads__find(struct threads *threads,= pid_t tid) struct thread *threads__findnew(struct threads *threads, pid_t pid, pid_t = tid, bool *created) { struct threads_table_entry *table =3D threads__table(threads, tid); - struct rb_node **p; - struct rb_node *parent =3D NULL; struct thread *res =3D NULL; - struct thread_rb_node *nd; - bool leftmost =3D true; =20 *created =3D false; down_write(&table->lock); - p =3D &table->entries.rb_root.rb_node; - while (*p !=3D NULL) { - struct thread *th; - - parent =3D *p; - th =3D rb_entry(parent, struct thread_rb_node, rb_node)->thread; - - if (thread__tid(th) =3D=3D tid) { - __threads_table_entry__set_last_match(table, th); - res =3D thread__get(th); - goto out_unlock; - } - - if (tid < thread__tid(th)) - p =3D &(*p)->rb_left; - else { - leftmost =3D false; - p =3D &(*p)->rb_right; - } - } - nd =3D malloc(sizeof(*nd)); - if (nd =3D=3D NULL) - goto out_unlock; res =3D thread__new(pid, tid); - if (!res) - free(nd); - else { - *created =3D true; - nd->thread =3D thread__get(res); - rb_link_node(&nd->rb_node, parent, p); - rb_insert_color_cached(&nd->rb_node, &table->entries, leftmost); - ++table->nr; - __threads_table_entry__set_last_match(table, res); + if (res) { + if (hashmap__add(&table->shard, tid, res)) { + /* Add failed. Assume a race so find other entry. */ + thread__put(res); + res =3D NULL; + if (hashmap__find(&table->shard, tid, &res)) + res =3D thread__get(res); + } else { + res =3D thread__get(res); + *created =3D true; + } + if (res) + __threads_table_entry__set_last_match(table, res); } -out_unlock: up_write(&table->lock); return res; } @@ -169,57 +136,32 @@ void threads__remove_all_threads(struct threads *thre= ads) { for (int i =3D 0; i < THREADS__TABLE_SIZE; i++) { struct threads_table_entry *table =3D &threads->table[i]; - struct rb_node *nd; + struct hashmap_entry *cur, *tmp; + size_t bkt; =20 down_write(&table->lock); __threads_table_entry__set_last_match(table, NULL); - nd =3D rb_first_cached(&table->entries); - while (nd) { - struct thread_rb_node *trb =3D rb_entry(nd, struct thread_rb_node, rb_n= ode); - - nd =3D rb_next(nd); - thread__put(trb->thread); - rb_erase_cached(&trb->rb_node, &table->entries); - RB_CLEAR_NODE(&trb->rb_node); - --table->nr; + hashmap__for_each_entry_safe((&table->shard), cur, tmp, bkt) { + struct thread *old_value; =20 - free(trb); + hashmap__delete(&table->shard, cur->key, /*old_key=3D*/NULL, &old_value= ); + thread__put(old_value); } - assert(table->nr =3D=3D 0); up_write(&table->lock); } } =20 void threads__remove(struct threads *threads, struct thread *thread) { - struct rb_node **p; struct threads_table_entry *table =3D threads__table(threads, thread__ti= d(thread)); - pid_t tid =3D thread__tid(thread); + struct thread *old_value; =20 down_write(&table->lock); if (table->last_match && RC_CHK_EQUAL(table->last_match, thread)) __threads_table_entry__set_last_match(table, NULL); =20 - p =3D &table->entries.rb_root.rb_node; - while (*p !=3D NULL) { - struct rb_node *parent =3D *p; - struct thread_rb_node *nd =3D rb_entry(parent, struct thread_rb_node, rb= _node); - struct thread *th =3D nd->thread; - - if (RC_CHK_EQUAL(th, thread)) { - thread__put(nd->thread); - rb_erase_cached(&nd->rb_node, &table->entries); - RB_CLEAR_NODE(&nd->rb_node); - --table->nr; - free(nd); - break; - } - - if (tid < thread__tid(th)) - p =3D &(*p)->rb_left; - else - p =3D &(*p)->rb_right; - } + hashmap__delete(&table->shard, thread__tid(thread), /*old_key=3D*/NULL, &= old_value); + thread__put(old_value); up_write(&table->lock); } =20 @@ -229,11 +171,11 @@ int threads__for_each_thread(struct threads *threads, { for (int i =3D 0; i < THREADS__TABLE_SIZE; i++) { struct threads_table_entry *table =3D &threads->table[i]; - struct rb_node *nd; + struct hashmap_entry *cur; + size_t bkt; =20 - for (nd =3D rb_first_cached(&table->entries); nd; nd =3D rb_next(nd)) { - struct thread_rb_node *trb =3D rb_entry(nd, struct thread_rb_node, rb_n= ode); - int rc =3D fn(trb->thread, data); + hashmap__for_each_entry((&table->shard), cur, bkt) { + int rc =3D fn((struct thread *)cur->pvalue, data); =20 if (rc !=3D 0) return rc; diff --git a/tools/perf/util/threads.h b/tools/perf/util/threads.h index ed67de627578..d03bd91a7769 100644 --- a/tools/perf/util/threads.h +++ b/tools/perf/util/threads.h @@ -2,7 +2,7 @@ #ifndef __PERF_THREADS_H #define __PERF_THREADS_H =20 -#include +#include "hashmap.h" #include "rwsem.h" =20 struct thread; @@ -11,9 +11,9 @@ struct thread; #define THREADS__TABLE_SIZE (1 << THREADS__TABLE_BITS) =20 struct threads_table_entry { - struct rb_root_cached entries; + /* Key is tid, value is struct thread. */ + struct hashmap shard; struct rw_semaphore lock; - unsigned int nr; struct thread *last_match; }; =20 --=20 2.43.0.rc1.413.gea7ed67945-goog