From nobody Mon Feb 9 03:11:15 2026 Received: from mail-yb1-f202.google.com (mail-yb1-f202.google.com [209.85.219.202]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 6C7C854737 for ; Fri, 1 Mar 2024 05:37:06 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.219.202 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709271428; cv=none; b=XeyjPkeYD/efwzHcsOMv3iFm4UtlnmfXAbuMCybNx0ZnzTR+FYCaz4b0n2KGlij0pLxhH1x+dx7ppD9FPahf/zRBQE+zdzyZwXP219vB8IuiIhpIxOxJdKHCenqrnLCyysiQsXOHonfbuPyL9KKdkRAbdF0fJGZPGN6Z0UqX/C0= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709271428; c=relaxed/simple; bh=SCdyCRIW2q68p5P5XIiezVRdNMVzHuD+AJIgIjGCWXw=; h=Date:In-Reply-To:Message-Id:Mime-Version:References:Subject:From: To:Content-Type; b=FiDmKpcYgUOYVhjPrqdKROaYDT9eI1I0haAH37pf5KGXZlWxxKqdWSjb9Z/r7E7ElvKuPqOQsU7Ig2U/zHvm1pwqZjxfTQQ01lVgDid+xvjMMHhewQA2efTMqYoo/kCuvT7ZeXjqXGO1cmb6XMhGZKSQ20hOrGkbaaN2s0B09jg= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--irogers.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=JsDqkn//; arc=none smtp.client-ip=209.85.219.202 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--irogers.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="JsDqkn//" Received: by mail-yb1-f202.google.com with SMTP id 3f1490d57ef6-dc693399655so3255764276.1 for ; Thu, 29 Feb 2024 21:37:06 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1709271425; x=1709876225; 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=G4IHp+rWZ6m2tdq1gZNE1l7uOaHQfZu8fsR6pOr+kRs=; b=JsDqkn//YlCBTmY+LxfyxyBNgms6u3MC0PQDXERBEVsj08UmXLaTdbQtXUGUmdumo7 Vg52LO9qSLQoE827beREGu8hvcMA8P1ZwPeETtwK2OQkojV0SWCgTg/5HZk/tOJhnnKt Nti+co1hamuw0ZuXhKmW6v7GBL2v8XewKtAugbbqbbDift03Pc0tAbub3FT+ucCgic5J 71AxLqXFjUFyJkHktTwvPplFw84LtEwKzuAkAceqmPA+V6WfXdhT5YrBBeHYVKlijzHU nIj4Kq8cQMpGsFdHtX7E4xzVTQYGx8DyK1s/3m6UVINGmd89OBRSqjyzrlWu1yrVa7aI YD8Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1709271425; x=1709876225; 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=G4IHp+rWZ6m2tdq1gZNE1l7uOaHQfZu8fsR6pOr+kRs=; b=S6hcSD1Bq+3/sE04rp+X05io6zgkbeikYqLf1izVvhMCOTDi43qIKgkjdUGGoJKEyB +yvWhPhNkvQQgsBpg6Y4/MjKs98+As+4iuLMWcX4Q6Ss1FwCp9E675bvc9afwLmV71Qc Fj2QUdJ1FN0nKX28izK4+80SvjL75g6GljwvyVt1C7cl3nqOiKqsn7rtrTYS8NImOdla z9eCDMFBwq/SDjgfoSlYRLfrTQUAC826rx9Sca29NnypMf2xrvDCvBwwpDz1pyE97Opt eXG+vYNQ5Ac5IMs5u+CkInT8bfThclqG/n4GCj5n6Dcjr1Ge5HqqJVrz2wNorsthtOTA XNDg== X-Forwarded-Encrypted: i=1; AJvYcCUn3U4bpoVuLv3A6NEnukiQnRh9VZq/ly/hxp7cAQNKnvddBUk/KJ4XLvqTTg+DlbXlPL+P1HppbtyHt1F9wSVqfN4iCMrlrJU5YPf0 X-Gm-Message-State: AOJu0YxEvhPne/vjS/Hl1Z8JdGNpKizTaH/IPVjvWuHqq0DQvcayt8p7 nRxNUs9QccsNSr9U1q7unp67P6QePGfMP2cjcVyzftC0/AUKD52WWvBYKKr2UvEGI3u30xXNs/S a/smWLg== X-Google-Smtp-Source: AGHT+IHDnJcerb+c7ZPfEF4j9tDeF/0/h6s4fjz+tv+cgtygpZuNEk0geTQ5pUO7WIcjdj5Uc3q5l8xOwCm2 X-Received: from irogers.svl.corp.google.com ([2620:15c:2a3:200:af4b:7fc1:b7be:fcb7]) (user=irogers job=sendgmr) by 2002:a05:6902:154d:b0:dcf:411d:67b9 with SMTP id r13-20020a056902154d00b00dcf411d67b9mr137956ybu.5.1709271425461; Thu, 29 Feb 2024 21:37:05 -0800 (PST) Date: Thu, 29 Feb 2024 21:36:44 -0800 In-Reply-To: <20240301053646.1449657-1-irogers@google.com> Message-Id: <20240301053646.1449657-7-irogers@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20240301053646.1449657-1-irogers@google.com> X-Mailer: git-send-email 2.44.0.278.ge034bb2e1d-goog Subject: [PATCH v4 6/7] perf threads: Switch from rbtree to hashmap From: Ian Rogers To: Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Namhyung Kim , Mark Rutland , Alexander Shishkin , Jiri Olsa , Ian Rogers , Adrian Hunter , Oliver Upton , Yang Jihong , linux-kernel@vger.kernel.org, linux-perf-users@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 db52d233c2de..ff2b169e0085 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 @@ -229,12 +171,12 @@ 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 down_read(&table->lock); - 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) { up_read(&table->lock); 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 2.44.0.278.ge034bb2e1d-goog