From nobody Sat Feb 7 17:42:12 2026 Received: from mail-yw1-f201.google.com (mail-yw1-f201.google.com [209.85.128.201]) (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 C02B714F977 for ; Tue, 27 Feb 2024 22:02:04 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.128.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709071326; cv=none; b=V9mBPQvyDcQ+pT9r8z1IESbiGHQUQyS+fZ+89owxq2as6QoxtdQ7bRyQgm91J9pdu6mJaj8LnQqVxl8qea/Uee3tJ5rFPFwtULbvbwnkZ/7N9uIo2pogMsdr73IKk3b6XjumIxE539IO7tzALPTwMyheuh/+aMWzduvUoqEgspI= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709071326; c=relaxed/simple; bh=nTFh+P14cGkIRFzkw+qc36gkHJ8idZHW4bN9FUCsVm4=; h=Date:In-Reply-To:Message-Id:Mime-Version:References:Subject:From: To:Content-Type; b=qhHWhaflExa9XEUzRzi0hqeE9+3wj8pyJE6ClmFfSKHaNeRnxdwpLf8dUf7TGWP64CoEperFP+Hne5F/Q+VSAm61yGniBPDvDwyJXE+ESle6QtSunZDqOiA0/C01aQjPONPgYM5viyq++8EOj9hMJHjL4/+Pjw4De2n2b1erka4= 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=brll3dw1; arc=none smtp.client-ip=209.85.128.201 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="brll3dw1" Received: by mail-yw1-f201.google.com with SMTP id 00721157ae682-6093a9ac959so1944547b3.3 for ; Tue, 27 Feb 2024 14:02:04 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1709071324; x=1709676124; 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=dRoLrl9KAry3tzXaKgMohq640cu15+1EIz2ffen2L4E=; b=brll3dw12jnOsBJqsQvfqxcC8AKa8x1mU4Q2WGdSo5Gi1nrZnI+zmFiqXi4+gMFtOc ZdE/grxMh9CqzMnlVKtJZ3vSrhQ91h4NVBFxcxpu75SdfF7LYk6i/WOw5MftQ3ADqVvS WPhSM19CVnMlcveFBIv4jGAP+PF7fawKYIojh+b6MVCxdi/1QSfEUx3spST6qv8Z6aFj xlU0Wi1mZpDBGmZvpDhOmjzUs5DyjO181TqD781hrm2wUQP8j/6V3Grw7yRYX4K75Auy ZEWqP41RLYHKspkMfW30H0s0vCsAhtYOTj33agz2WMBJ+PQdlpUqbqPSUzZCBDVSwZNn vo6A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1709071324; x=1709676124; 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=dRoLrl9KAry3tzXaKgMohq640cu15+1EIz2ffen2L4E=; b=VVIjJQ9ocTPxLDDWAbAEuu3G00HVcp+SjqHL5V/Buj3niNdHnctLdeu2CHWCgETnbG FwmARNusOLIyARjI+Yk7pUQJSXXZHRJkmpVrdUxWgEs0+MyP2hYMcdewdcF0l9BD5Mbu YtYeHMYv+t1DwlKhnka4evyB49zVPV9OH0n7DVV8hr9ssSbCbHswfrV1VIzTSwhReq2s GB8hb0Yyr6bPXzC0v+yaG+ULmDPtXE6gPoxUTJPz9HKqpFes14GZnqqmwLwLwEWlmTAy pCB/JTL1S8257soKLeXzXIzSSfbVUpNUqb84g+dzy6nVm3HfVZmWN5+ONCnE7JHQlNPL ZAbw== X-Forwarded-Encrypted: i=1; AJvYcCXxu4H2covZPLwNnynmkzFjNJCeJyQT/GLMyCYJS4aAmTpWIurYnZSJkBTct9qp8VZRZx/5omihptPIlQOqvsd0YphYxyna+Gq+SuMV X-Gm-Message-State: AOJu0YyRKLKovctLNIL511ny+vHMkx1cVMAfF2tcYa/XYdOPVNlm0nls Mc1TxVn1iG7uB8I+cIp/hMwSBv39DLvy+w88PzDdy4jKQNymJj11n/osEvXTmCCg95Q0GDWturS G85+F+g== X-Google-Smtp-Source: AGHT+IFLGMh98iH0mZ6Yu29Ky3q/9XntDi0fiWAHIN9LZQ8Tgu6GUWndo9l+iJoKuyOa3tHwuW5iGfa1EY1d X-Received: from irogers.svl.corp.google.com ([2620:15c:2a3:200:4ff1:8af6:9e1a:6382]) (user=irogers job=sendgmr) by 2002:a25:b90b:0:b0:dc6:d890:1a97 with SMTP id x11-20020a25b90b000000b00dc6d8901a97mr32083ybj.9.1709071323863; Tue, 27 Feb 2024 14:02:03 -0800 (PST) Date: Tue, 27 Feb 2024 14:01:45 -0800 In-Reply-To: <20240227220150.3876198-1-irogers@google.com> Message-Id: <20240227220150.3876198-2-irogers@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20240227220150.3876198-1-irogers@google.com> X-Mailer: git-send-email 2.44.0.rc1.240.g4c46232300-goog Subject: [PATCH v2 1/6] perf report: Sort child tasks by tid From: Ian Rogers To: Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Namhyung Kim , Mark Rutland , Alexander Shishkin , Jiri Olsa , Ian Rogers , Adrian Hunter , Kan Liang , Oliver Upton , Yang Jihong , linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, bpf@vger.kernel.org Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Commit 91e467bc568f ("perf machine: Use hashtable for machine threads") made the iteration of thread tids unordered. The perf report --tasks output now shows child threads in an order determined by the hashing. For example, in this snippet tid 3 appears after tid 256 even though they have the same ppid 2: ``` $ perf report --tasks % pid tid ppid comm 0 0 -1 |swapper 2 2 0 | kthreadd 256 256 2 | kworker/12:1H-k 693761 693761 2 | kworker/10:1-mm 1301762 1301762 2 | kworker/1:1-mm_ 1302530 1302530 2 | kworker/u32:0-k 3 3 2 | rcu_gp ... ``` The output is easier to read if threads appear numerically increasing. To allow for this, read all threads into a list then sort with a comparator that orders by the child task's of the first common parent. The list creation and deletion are created as utilities on machine. The indentation is possible by counting the number of parents a child has. With this change the output for the same data file is now like: ``` $ perf report --tasks % pid tid ppid comm 0 0 -1 |swapper 1 1 0 | systemd 823 823 1 | systemd-journal 853 853 1 | systemd-udevd 3230 3230 1 | systemd-timesyn 3236 3236 1 | auditd 3239 3239 3236 | audisp-syslog 3321 3321 1 | accounts-daemon ... ``` Signed-off-by: Ian Rogers --- tools/perf/builtin-report.c | 217 +++++++++++++++++++++--------------- tools/perf/util/machine.c | 30 +++++ tools/perf/util/machine.h | 10 ++ 3 files changed, 168 insertions(+), 89 deletions(-) diff --git a/tools/perf/builtin-report.c b/tools/perf/builtin-report.c index 8e16fa261e6f..dcd93ee5fc24 100644 --- a/tools/perf/builtin-report.c +++ b/tools/perf/builtin-report.c @@ -59,6 +59,7 @@ #include #include #include +#include #include #include #include @@ -828,35 +829,6 @@ static void tasks_setup(struct report *rep) rep->tool.no_warn =3D true; } =20 -struct task { - struct thread *thread; - struct list_head list; - struct list_head children; -}; - -static struct task *tasks_list(struct task *task, struct machine *machine) -{ - struct thread *parent_thread, *thread =3D task->thread; - struct task *parent_task; - - /* Already listed. */ - if (!list_empty(&task->list)) - return NULL; - - /* Last one in the chain. */ - if (thread__ppid(thread) =3D=3D -1) - return task; - - parent_thread =3D machine__find_thread(machine, -1, thread__ppid(thread)); - if (!parent_thread) - return ERR_PTR(-ENOENT); - - parent_task =3D thread__priv(parent_thread); - thread__put(parent_thread); - list_add_tail(&task->list, &parent_task->children); - return tasks_list(parent_task, machine); -} - struct maps__fprintf_task_args { int indent; FILE *fp; @@ -900,89 +872,156 @@ static size_t maps__fprintf_task(struct maps *maps, = int indent, FILE *fp) return args.printed; } =20 -static void task__print_level(struct task *task, FILE *fp, int level) +static int thread_level(struct machine *machine, const struct thread *thre= ad) { - struct thread *thread =3D task->thread; - struct task *child; - int comm_indent =3D fprintf(fp, " %8d %8d %8d |%*s", - thread__pid(thread), thread__tid(thread), - thread__ppid(thread), level, ""); + struct thread *parent_thread; + int res; =20 - fprintf(fp, "%s\n", thread__comm_str(thread)); + if (thread__tid(thread) <=3D 0) + return 0; =20 - maps__fprintf_task(thread__maps(thread), comm_indent, fp); + if (thread__ppid(thread) <=3D 0) + return 1; =20 - if (!list_empty(&task->children)) { - list_for_each_entry(child, &task->children, list) - task__print_level(child, fp, level + 1); + parent_thread =3D machine__find_thread(machine, -1, thread__ppid(thread)); + if (!parent_thread) { + pr_err("Missing parent thread of %d\n", thread__tid(thread)); + return 0; } + res =3D 1 + thread_level(machine, parent_thread); + thread__put(parent_thread); + return res; } =20 -static int tasks_print(struct report *rep, FILE *fp) +static void task__print_level(struct machine *machine, struct thread *thre= ad, FILE *fp) { - struct perf_session *session =3D rep->session; - struct machine *machine =3D &session->machines.host; - struct task *tasks, *task; - unsigned int nr =3D 0, itask =3D 0, i; - struct rb_node *nd; - LIST_HEAD(list); + int level =3D thread_level(machine, thread); + int comm_indent =3D fprintf(fp, " %8d %8d %8d |%*s", + thread__pid(thread), thread__tid(thread), + thread__ppid(thread), level, ""); =20 - /* - * No locking needed while accessing machine->threads, - * because --tasks is single threaded command. - */ + fprintf(fp, "%s\n", thread__comm_str(thread)); =20 - /* Count all the threads. */ - for (i =3D 0; i < THREADS__TABLE_SIZE; i++) - nr +=3D machine->threads[i].nr; + maps__fprintf_task(thread__maps(thread), comm_indent, fp); +} =20 - tasks =3D malloc(sizeof(*tasks) * nr); - if (!tasks) - return -ENOMEM; +/* + * Sort two thread list nodes such that they form a tree. The first node i= s the + * root of the tree, its children are ordered numerically after it. If a c= hild + * has children itself then they appear immediately after their parent. For + * example, the 4 threads in the order they'd appear in the list: + * - init with a TID 1 and a parent of 0 + * - systemd with a TID 3000 and a parent of init/1 + * - systemd child thread with TID 4000, the parent is 3000 + * - NetworkManager is a child of init with a TID of 3500. + */ +static int task_list_cmp(void *priv, const struct list_head *la, const str= uct list_head *lb) +{ + struct machine *machine =3D priv; + struct thread_list *task_a =3D list_entry(la, struct thread_list, list); + struct thread_list *task_b =3D list_entry(lb, struct thread_list, list); + struct thread *a =3D task_a->thread; + struct thread *b =3D task_b->thread; + int level_a, level_b, res; + + /* Same thread? */ + if (thread__tid(a) =3D=3D thread__tid(b)) + return 0; =20 - for (i =3D 0; i < THREADS__TABLE_SIZE; i++) { - struct threads *threads =3D &machine->threads[i]; + /* Compare a and b to root. */ + if (thread__tid(a) =3D=3D 0) + return -1; =20 - for (nd =3D rb_first_cached(&threads->entries); nd; - nd =3D rb_next(nd)) { - task =3D tasks + itask++; + if (thread__tid(b) =3D=3D 0) + return 1; =20 - task->thread =3D rb_entry(nd, struct thread_rb_node, rb_node)->thread; - INIT_LIST_HEAD(&task->children); - INIT_LIST_HEAD(&task->list); - thread__set_priv(task->thread, task); - } - } + /* If parents match sort by tid. */ + if (thread__ppid(a) =3D=3D thread__ppid(b)) + return thread__tid(a) < thread__tid(b) ? -1 : 1; =20 /* - * Iterate every task down to the unprocessed parent - * and link all in task children list. Task with no - * parent is added into 'list'. + * Find a and b such that if they are a child of each other a and b's + * tid's match, otherwise a and b have a common parent and distinct + * tid's to sort by. First make the depths of the threads match. */ - for (itask =3D 0; itask < nr; itask++) { - task =3D tasks + itask; - - if (!list_empty(&task->list)) - continue; - - task =3D tasks_list(task, machine); - if (IS_ERR(task)) { - pr_err("Error: failed to process tasks\n"); - free(tasks); - return PTR_ERR(task); + level_a =3D thread_level(machine, a); + level_b =3D thread_level(machine, b); + a =3D thread__get(a); + b =3D thread__get(b); + for (int i =3D level_a; i > level_b; i--) { + struct thread *parent =3D machine__find_thread(machine, -1, thread__ppid= (a)); + + thread__put(a); + if (!parent) { + pr_err("Missing parent thread of %d\n", thread__tid(a)); + thread__put(b); + return -1; } + a =3D parent; + } + for (int i =3D level_b; i > level_a; i--) { + struct thread *parent =3D machine__find_thread(machine, -1, thread__ppid= (b)); =20 - if (task) - list_add_tail(&task->list, &list); + thread__put(b); + if (!parent) { + pr_err("Missing parent thread of %d\n", thread__tid(b)); + thread__put(a); + return 1; + } + b =3D parent; + } + /* Search up to a common parent. */ + while (thread__ppid(a) !=3D thread__ppid(b)) { + struct thread *parent; + + parent =3D machine__find_thread(machine, -1, thread__ppid(a)); + thread__put(a); + if (!parent) + pr_err("Missing parent thread of %d\n", thread__tid(a)); + a =3D parent; + parent =3D machine__find_thread(machine, -1, thread__ppid(b)); + thread__put(b); + if (!parent) + pr_err("Missing parent thread of %d\n", thread__tid(b)); + b =3D parent; + if (!a || !b) { + /* Handle missing parent (unexpected) with some sanity. */ + thread__put(a); + thread__put(b); + return !a && !b ? 0 : (!a ? -1 : 1); + } + } + if (thread__tid(a) =3D=3D thread__tid(b)) { + /* a is a child of b or vice-versa, deeper levels appear later. */ + res =3D level_a < level_b ? -1 : (level_a > level_b ? 1 : 0); + } else { + /* Sort by tid now the parent is the same. */ + res =3D thread__tid(a) < thread__tid(b) ? -1 : 1; } + thread__put(a); + thread__put(b); + return res; +} =20 - fprintf(fp, "# %8s %8s %8s %s\n", "pid", "tid", "ppid", "comm"); +static int tasks_print(struct report *rep, FILE *fp) +{ + struct machine *machine =3D &rep->session->machines.host; + LIST_HEAD(tasks); + int ret; =20 - list_for_each_entry(task, &list, list) - task__print_level(task, fp, 0); + ret =3D machine__thread_list(machine, &tasks); + if (!ret) { + struct thread_list *task; =20 - free(tasks); - return 0; + list_sort(machine, &tasks, task_list_cmp); + + fprintf(fp, "# %8s %8s %8s %s\n", "pid", "tid", "ppid", "comm"); + + list_for_each_entry(task, &tasks, list) + task__print_level(machine, task->thread, fp); + } + thread_list__delete(&tasks); + return ret; } =20 static int __cmd_report(struct report *rep) diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c index 3da92f18814a..7872ce92c9fc 100644 --- a/tools/perf/util/machine.c +++ b/tools/perf/util/machine.c @@ -3261,6 +3261,36 @@ int machines__for_each_thread(struct machines *machi= nes, return rc; } =20 + +static int thread_list_cb(struct thread *thread, void *data) +{ + struct list_head *list =3D data; + struct thread_list *entry =3D malloc(sizeof(*entry)); + + if (!entry) + return -ENOMEM; + + entry->thread =3D thread__get(thread); + list_add_tail(&entry->list, list); + return 0; +} + +int machine__thread_list(struct machine *machine, struct list_head *list) +{ + return machine__for_each_thread(machine, thread_list_cb, list); +} + +void thread_list__delete(struct list_head *list) +{ + struct thread_list *pos, *next; + + list_for_each_entry_safe(pos, next, list, list) { + thread__zput(pos->thread); + list_del(&pos->list); + free(pos); + } +} + pid_t machine__get_current_tid(struct machine *machine, int cpu) { if (cpu < 0 || (size_t)cpu >=3D machine->current_tid_sz) diff --git a/tools/perf/util/machine.h b/tools/perf/util/machine.h index 1279acda6a8a..b738ce84817b 100644 --- a/tools/perf/util/machine.h +++ b/tools/perf/util/machine.h @@ -280,6 +280,16 @@ int machines__for_each_thread(struct machines *machine= s, int (*fn)(struct thread *thread, void *p), void *priv); =20 +struct thread_list { + struct list_head list; + struct thread *thread; +}; + +/* Make a list of struct thread_list based on threads in the machine. */ +int machine__thread_list(struct machine *machine, struct list_head *list); +/* Free up the nodes within the thread_list list. */ +void thread_list__delete(struct list_head *list); + pid_t machine__get_current_tid(struct machine *machine, int cpu); int machine__set_current_tid(struct machine *machine, int cpu, pid_t pid, pid_t tid); --=20 2.44.0.rc1.240.g4c46232300-goog From nobody Sat Feb 7 17:42:12 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 006C8151CD9 for ; Tue, 27 Feb 2024 22:02:06 +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=1709071328; cv=none; b=KQiNNqCEjICtn4Pz9ff/j/DFEcVtcL1gLSNFnIWLWcvmEEzCE52e1qbAG10T3WlE4U3xKDt4Hg+mK6BAWtMwmcjDaXNMgwd8vFZItLJ3IdF2tr4m6PDJmUibeKR5cgMwkm6T9xgsJpgjoIs2++VhQXHzFe0PvFMTGR7mr1ZEwXo= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709071328; c=relaxed/simple; bh=louA5ITf0PB9gTEbmjxtVgELJEkk9dAW1fzHeRrbwTQ=; h=Date:In-Reply-To:Message-Id:Mime-Version:References:Subject:From: To:Content-Type; b=J3nS7AHnbYs4nGVEwpuFL/5+ViUMdl8/tMuy1L6A3Zxf3yTY7KVAT29AJ0KAhwDzB6SyPqMxgAypU6ZYn0ebEtaeywfohUHEM/Q1Icoy5FESoQcdQqtv06i36ZGh+iRN6wAJow3d0CcrB8J7oqCy2PGZS4wLwNeaKosKecEdY68= 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=2+ezsV03; 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="2+ezsV03" Received: by mail-yb1-f202.google.com with SMTP id 3f1490d57ef6-dcf22e5b70bso8605973276.1 for ; Tue, 27 Feb 2024 14:02:06 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1709071326; x=1709676126; 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=/FMLMbsrzbdkn9O9XsKWx3S12UuVwdsAjVLGeB/eBZI=; b=2+ezsV035YYGdi1fQZHX7QXaKBcwAriZoTOm1Sw5aUUGe11VbnONJEpYnrxzRBBpMI 7XnFs5/BAIKzXCWsVn0eGJd+XMsXToE666mzs7qrh2LvC75PUwEqEDOschKvFabrIwVw jxEXQe/4v763Le9x3rOLQirCC1CZzYKcYNum2o0SOEYRo77jGnEAMHGhP3dETMKEeifx wgXhasDLkcqJde9u5QKillgECiqwXCsabDYG/3BoETwLijhHQvLL2A6g9g8tsGZA8ciV I5JLi8SAN25d9vBP/m+kQh/+XxV+Vm66FEslpn8lo/GQJcm0iih/jKtsAhnIMbs5Dgkr 0W4g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1709071326; x=1709676126; 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=/FMLMbsrzbdkn9O9XsKWx3S12UuVwdsAjVLGeB/eBZI=; b=OKEHgZvZZ6tsgClrVipgT1b+DppbMcnx2zfmpuepx9+9HWXE3pDejg6L/Lq4jj5ZXQ jzf+4Sp3fo/E+P2P5pf0dvNPGRVK2fGTJdTdkKwmRqBozJ7eq04qhbv8LGogLFq/L/8T qUVc4cq4/QyzZ8A+NR4hYGwc69SwL/gTa/QBTzFUhHD36jXhUnTnvTm82pvkZw41Wtku BfWa9A5hIKJqdFtpycW+VVOfXED1aDjbly9XqmIFpgbq/r/0zJ7kZaEhIDTUJvTUyKSD nR81OjFy2h/7QPcC39K7RyHD91an9wdNec+s8ejhsQiHhGC2noRXzR2vH1PqErRaEJa2 ChTg== X-Forwarded-Encrypted: i=1; AJvYcCUiKVt9jeu4bZHyAsMZDlCAPd6YQYV+xJfv9UADWnG3tIS+7ZcfzSE+EZkBhcobFrB9c+bPFqLCHa0n9e9qBaDa5vka0QynpZtT+rxy X-Gm-Message-State: AOJu0Yx3ca20WTyVUq315RaZX0VCgLJm2+Oso6rztZNBmBolOKN5DFzM pToj4TOP2P0R7RrXHguXmzFGtdiegeYOkdjGTvrsmYW3+YLAG/M+57KzI86c3ebV2QvjaH5ltsV EgRwYvQ== X-Google-Smtp-Source: AGHT+IGtgwaXt2Ye5Ot4T80iOqTZS9VHVj3XpgeYVsVpc6gFFqbM+RpqUmaenndL8w6+NNw6P+6xudzHiI8e X-Received: from irogers.svl.corp.google.com ([2620:15c:2a3:200:4ff1:8af6:9e1a:6382]) (user=irogers job=sendgmr) by 2002:a05:6902:150a:b0:dc6:d9eb:6422 with SMTP id q10-20020a056902150a00b00dc6d9eb6422mr32279ybu.10.1709071326081; Tue, 27 Feb 2024 14:02:06 -0800 (PST) Date: Tue, 27 Feb 2024 14:01:46 -0800 In-Reply-To: <20240227220150.3876198-1-irogers@google.com> Message-Id: <20240227220150.3876198-3-irogers@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20240227220150.3876198-1-irogers@google.com> X-Mailer: git-send-email 2.44.0.rc1.240.g4c46232300-goog Subject: [PATCH v2 2/6] perf trace: Ignore thread hashing in summary From: Ian Rogers To: Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Namhyung Kim , Mark Rutland , Alexander Shishkin , Jiri Olsa , Ian Rogers , Adrian Hunter , Kan Liang , Oliver Upton , Yang Jihong , linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, bpf@vger.kernel.org Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Commit 91e467bc568f ("perf machine: Use hashtable for machine threads") made the iteration of thread tids unordered. The perf trace --summary output sorts and prints each hash bucket, rather than all threads globally. Change this behavior by turn all threads into a list, sort the list by number of trace events then by tids, finally print the list. This also allows the rbtree in threads to be not accessed outside of machine. Signed-off-by: Ian Rogers --- tools/perf/builtin-trace.c | 41 +++++++++++++++++++++---------------- tools/perf/util/rb_resort.h | 5 ----- 2 files changed, 23 insertions(+), 23 deletions(-) diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c index 109b8e64fe69..90eaff8c0f6e 100644 --- a/tools/perf/builtin-trace.c +++ b/tools/perf/builtin-trace.c @@ -74,6 +74,7 @@ #include #include #include +#include #include #include #include @@ -4312,34 +4313,38 @@ static unsigned long thread__nr_events(struct threa= d_trace *ttrace) return ttrace ? ttrace->nr_events : 0; } =20 -DEFINE_RESORT_RB(threads, - (thread__nr_events(thread__priv(a->thread)) < - thread__nr_events(thread__priv(b->thread))), - struct thread *thread; -) +static int trace_nr_events_cmp(void *priv __maybe_unused, + const struct list_head *la, + const struct list_head *lb) { - entry->thread =3D rb_entry(nd, struct thread_rb_node, rb_node)->thread; + struct thread_list *a =3D list_entry(la, struct thread_list, list); + struct thread_list *b =3D list_entry(lb, struct thread_list, list); + unsigned long a_nr_events =3D thread__nr_events(thread__priv(a->thread)); + unsigned long b_nr_events =3D thread__nr_events(thread__priv(b->thread)); + + if (a_nr_events !=3D b_nr_events) + return a_nr_events < b_nr_events ? -1 : 1; + + /* Identical number of threads, place smaller tids first. */ + return thread__tid(a->thread) < thread__tid(b->thread) + ? -1 + : (thread__tid(a->thread) > thread__tid(b->thread) ? 1 : 0); } =20 static size_t trace__fprintf_thread_summary(struct trace *trace, FILE *fp) { size_t printed =3D trace__fprintf_threads_header(fp); - struct rb_node *nd; - int i; - - for (i =3D 0; i < THREADS__TABLE_SIZE; i++) { - DECLARE_RESORT_RB_MACHINE_THREADS(threads, trace->host, i); + LIST_HEAD(threads); =20 - if (threads =3D=3D NULL) { - fprintf(fp, "%s", "Error sorting output by nr_events!\n"); - return 0; - } + if (machine__thread_list(trace->host, &threads) =3D=3D 0) { + struct thread_list *pos; =20 - resort_rb__for_each_entry(nd, threads) - printed +=3D trace__fprintf_thread(fp, threads_entry->thread, trace); + list_sort(NULL, &threads, trace_nr_events_cmp); =20 - resort_rb__delete(threads); + list_for_each_entry(pos, &threads, list) + printed +=3D trace__fprintf_thread(fp, pos->thread, trace); } + thread_list__delete(&threads); return printed; } =20 diff --git a/tools/perf/util/rb_resort.h b/tools/perf/util/rb_resort.h index 376e86cb4c3c..d927a0d25052 100644 --- a/tools/perf/util/rb_resort.h +++ b/tools/perf/util/rb_resort.h @@ -143,9 +143,4 @@ struct __name##_sorted *__name =3D __name##_sorted__new DECLARE_RESORT_RB(__name)(&__ilist->rblist.entries.rb_root, \ __ilist->rblist.nr_entries) =20 -/* For 'struct machine->threads' */ -#define DECLARE_RESORT_RB_MACHINE_THREADS(__name, __machine, hash_bucket) = \ - DECLARE_RESORT_RB(__name)(&__machine->threads[hash_bucket].entries.rb_roo= t, \ - __machine->threads[hash_bucket].nr) - #endif /* _PERF_RESORT_RB_H_ */ --=20 2.44.0.rc1.240.g4c46232300-goog From nobody Sat Feb 7 17:42:12 2026 Received: from mail-yw1-f201.google.com (mail-yw1-f201.google.com [209.85.128.201]) (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 A7AA4153BCD for ; Tue, 27 Feb 2024 22:02:09 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.128.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709071332; cv=none; b=HeFDIi/eDCln2Hid5BZ2qG+nivS8ZG18iYQstb+yiALw5DrUywk88CWNfEewC2lsuz1nULwPzjWLRwyriatzxSvfZ6BY1yJuH4/pKm25/OC59fuotg1Vv2XvfR70vw2OTOa2Bz/5m0vvNtB0T1kN9d/btAqjo4CKl0IzA2CUQTE= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709071332; c=relaxed/simple; bh=/yGeJM1MC3xrnGlw+YrOzjUeVSCpkNh+lS2W25QBImY=; h=Date:In-Reply-To:Message-Id:Mime-Version:References:Subject:From: To:Content-Type; b=D64A8+mMkY3LzB25EwDAQWyaazk5RJo7v9vlKS6i+vAlVnyscg5Ge3RHv9lOLH0+q+5lk00G6jGmDDbuQRJoPqlohJ3e75I+d1RgHGBi6kNQmmXNVvi6YNvB/XmEX1dHfPfT1SPEmsFr/TynYB/ZFHZzsSs8LIM2+6VY4M77lFk= 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=4dleXVlg; arc=none smtp.client-ip=209.85.128.201 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="4dleXVlg" Received: by mail-yw1-f201.google.com with SMTP id 00721157ae682-608ad239f8fso82021337b3.0 for ; Tue, 27 Feb 2024 14:02:09 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1709071329; x=1709676129; 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=LLvFhK5uL/QCeGE47QDYifrDggRxdFdeVaa+ektv4Ks=; b=4dleXVlggqGls83VLDgVmaAYqUTq7J/uiSL0iJc+KNyKLNICbsipEW97LvJweK32Hv XCGViPHcDRN0RZ9MzTlYCKWgog99NebLaguxMTvpcQJxNJf/Nwo7FWdzlMiE0VSMyvut RcNvasddobo2cv9jO/pwsLSS5swYhqMc1N/EhvgjCp7YmAyg/nkN8JGo82rYbHN+EKGa H3sdYTUZPFJdYf0nJOi8GloAulR6WFLIo114Gm1Ovwt5e7K6/iXsHgXSbm+N2VpDXrkN Sa0jJEbxXjdsnmU0bpuECXAJkR0DYXJT+5lKwsBNkRRtJ+Qo5Aq7NXTALOoh0FZxcOHH 2stA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1709071329; x=1709676129; 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=LLvFhK5uL/QCeGE47QDYifrDggRxdFdeVaa+ektv4Ks=; b=UchK9s/7rOwtSBbuy32P9LElPH4slwQdYwGl1EpjARRq2CASkUzIBhXLOiBYkDmcIm EQbJAXU36MUesYOZZIoja7d8hd3qqeq4uqF9kb8/D8xEBP+pxGeIbGVzC6y7IUrqq/5z TsNrPNwcXwULEB6XZhNnPV5jUIZ5ZxNplzX0zZ8C1of4sNZPvJ9L13LRxXxBFYe8WAwx PsrgqAYc6mRXz8TudcWJvdCMtipmcdBQlVNSpdPqymZrX0jiMUJ58dyLkDMymQvOtpV7 amJ9wa7EDE1isrHES1TbYEVDAl4NFRQIT8KgZtW12DrjbUGuk6ztp4TgrzNaW2sWOJ3N BjeA== X-Forwarded-Encrypted: i=1; AJvYcCVmCLFl7BqQowC3P0Pvw47Fi4ZYn1MLrr1u35EAnbeXolhK54WRzflyScP0dKq/TZBgWp/WXncYojP7AdP90TdtarwCpWAeIiLcIKdX X-Gm-Message-State: AOJu0YwSHi8AHnCZKlbxfIveBTlDa4KGbMJlGLI8EXWESCENHVT0kyw9 veHBioEvmCzReQX4JL6y27f2E1RBfAd9RhHD6ZbSmSRHjDbTyNdHm2A3btm13QimhLTTrIb9Uw/ rxeidjg== X-Google-Smtp-Source: AGHT+IGZSMnaIsAQtX/ldCpU/7po8oMpdQxnfEczmc5sne5RHle1yvyEtqmQ/soBLtduA34btzf9Vr/IMJAe X-Received: from irogers.svl.corp.google.com ([2620:15c:2a3:200:4ff1:8af6:9e1a:6382]) (user=irogers job=sendgmr) by 2002:a81:a08f:0:b0:608:e711:5a5a with SMTP id x137-20020a81a08f000000b00608e7115a5amr807524ywg.1.1709071328756; Tue, 27 Feb 2024 14:02:08 -0800 (PST) Date: Tue, 27 Feb 2024 14:01:47 -0800 In-Reply-To: <20240227220150.3876198-1-irogers@google.com> Message-Id: <20240227220150.3876198-4-irogers@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20240227220150.3876198-1-irogers@google.com> X-Mailer: git-send-email 2.44.0.rc1.240.g4c46232300-goog Subject: [PATCH v2 3/6] perf machine: Move fprintf to for_each loop and a callback From: Ian Rogers To: Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Namhyung Kim , Mark Rutland , Alexander Shishkin , Jiri Olsa , Ian Rogers , Adrian Hunter , Kan Liang , Oliver Upton , Yang Jihong , linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, bpf@vger.kernel.org Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Avoid exposing the threads data structure by switching to the callback machine__for_each_thread approach. machine__fprintf is only used in tests and verbose >3 output so don't turn to list and sort. Add machine__threads_nr to be refactored later. Note, all existing *_fprintf routines ignore fprintf errors. Signed-off-by: Ian Rogers --- tools/perf/util/machine.c | 43 ++++++++++++++++++++++++--------------- 1 file changed, 27 insertions(+), 16 deletions(-) diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c index 7872ce92c9fc..e072b2115b64 100644 --- a/tools/perf/util/machine.c +++ b/tools/perf/util/machine.c @@ -1113,29 +1113,40 @@ size_t machine__fprintf_vmlinux_path(struct machine= *machine, FILE *fp) return printed; } =20 -size_t machine__fprintf(struct machine *machine, FILE *fp) +struct machine_fprintf_cb_args { + FILE *fp; + size_t printed; +}; + +static int machine_fprintf_cb(struct thread *thread, void *data) { - struct rb_node *nd; - size_t ret; - int i; + struct machine_fprintf_cb_args *args =3D data; =20 - for (i =3D 0; i < THREADS__TABLE_SIZE; i++) { - struct threads *threads =3D &machine->threads[i]; + /* TODO: handle fprintf errors. */ + args->printed +=3D thread__fprintf(thread, args->fp); + return 0; +} =20 - down_read(&threads->lock); +static size_t machine__threads_nr(const struct machine *machine) +{ + size_t nr =3D 0; =20 - ret =3D fprintf(fp, "Threads: %u\n", threads->nr); + for (int i =3D 0; i < THREADS__TABLE_SIZE; i++) + nr +=3D machine->threads[i].nr; =20 - for (nd =3D rb_first_cached(&threads->entries); nd; - nd =3D rb_next(nd)) { - struct thread *pos =3D rb_entry(nd, struct thread_rb_node, rb_node)->th= read; + return nr; +} =20 - ret +=3D thread__fprintf(pos, fp); - } +size_t machine__fprintf(struct machine *machine, FILE *fp) +{ + struct machine_fprintf_cb_args args =3D { + .fp =3D fp, + .printed =3D 0, + }; + size_t ret =3D fprintf(fp, "Threads: %zu\n", machine__threads_nr(machine)= ); =20 - up_read(&threads->lock); - } - return ret; + machine__for_each_thread(machine, machine_fprintf_cb, &args); + return ret + args.printed; } =20 static struct dso *machine__get_kernel(struct machine *machine) --=20 2.44.0.rc1.240.g4c46232300-goog From nobody Sat Feb 7 17:42:12 2026 Received: from mail-yw1-f202.google.com (mail-yw1-f202.google.com [209.85.128.202]) (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 16396156963 for ; Tue, 27 Feb 2024 22:02:11 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.128.202 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709071334; cv=none; b=gLXB0F9j7hyhREZjlbuRvlhwgqmkvBilk467MwMsdwq4N5YZieY7XR5o083+iYV4lV7wdqagU6cJeK+t/p3lWSqhjwUb/xnZlRlvJyJKoMutOaYOjHvr4fTnB9Y9NpyqoPZqc1updrfnZWQcaM7MsmLDFhgTpznOeCFL7sVqO7Q= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709071334; c=relaxed/simple; bh=BwcV35MQ9IkUkXfZ67mXHHWsr4b/gkiZgBHtVuRfRT8=; h=Date:In-Reply-To:Message-Id:Mime-Version:References:Subject:From: To:Content-Type; b=d5OZocfkhKYTVFNptfVEJ4V0xGsisxnFnqAzUIvUkn8XywswYJDR5DEKi1uXa+RLDIUy2l9UUCAfJCuOzF6O++uhhs/KUjzyNky7Mg4a3VxkBo4JgYT/QIVMi3v7RKCb/RdtOz26F7p+QK0DrB04qe+dMEL0QM0b6II3pppevn8= 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=RL532pKU; arc=none smtp.client-ip=209.85.128.202 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="RL532pKU" Received: by mail-yw1-f202.google.com with SMTP id 00721157ae682-607cd6c11d7so75668517b3.0 for ; Tue, 27 Feb 2024 14:02:11 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1709071331; x=1709676131; 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=ImEDViDBOcqCHKqHKXmTVraxu3CYSvL5VkrRz+GpsCo=; b=RL532pKU8yYvYtM1DYrnK0nqiCSzXF4pq4zwV9m63odZJJxR3dnA8GCuF/eUvGdjUT xP1e02aH+ZlyhkWkJQz5wt+QqPIQibrJ9O7ZmqE10XiwMxbRE679X5aMXdeaxBX1fN4S hMQxQy0dZJEpmO2dH9lxXPmRr3M46BBmvHyKBpEgnu4wMpM3+0/rRftg6IoXEONpMmiV Pe/l0uddR2ST0stQ03jQCDtKULMX9bHJgcBTCwzkbLO1mKM3oVMLCVlUsJ5Yo8KCXibY iyGBNns5NLyjD0kwPt9ttOjyjOxqy6KYsUmhno9ToCWgZ22yUBgWJRDgelJ4nsmad2ZK s9tA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1709071331; x=1709676131; 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=ImEDViDBOcqCHKqHKXmTVraxu3CYSvL5VkrRz+GpsCo=; b=Kf326XqIomuik85iAjzUEEgzraJqZ8ieRxz8pV0oh+11EfjRV7wcTxcKUn0WZrX8lM pOPbmbzUVUtC+POTfWpzziH8isDs0zNMwj5S7GzqceOQL0BvzF9bjyTp9gyAQwz3aOr9 4OaX/jKa5wv0GRpDXWADzjfBF2ygIN1N8FMEaQX6jb+5/2rrCLkNu9XSNSVmc1qUdIzh HRhXWOezOwY+DaNpr3S/qtCBnrWVAuOHJFuSfFID52q9Uh1Y/AYPH9lpRs59+vatKx4t 0UQAKN/SDRTzHEwkMgxMLmKjh8MJF+jJn2nDXmDTAJxqlofaC6TAKH4ubNo+7Nwi5Ji7 v2Dw== X-Forwarded-Encrypted: i=1; AJvYcCUNXm21yWjLkvr0QnDOe1a18tUDgMHEz9EToUdDn+Uwz4aX5zlCt7OiD48SQij6YIY9MAJsl/EU8LW9wzkGomxi33gF0hQ+NMqAenW1 X-Gm-Message-State: AOJu0Yyt4ZJ2Qq3/Utziu7LLcvkRuE0caxCrctg7ITrooA3NnzaPtlfV LhtbL0TQTr9InZN9HiRS79sUlOl/BlCqePoViunw4G4BMhEKa1rxoerbVfa0JSZLad16cux3kTM qA2hw1g== X-Google-Smtp-Source: AGHT+IEkU3Paxse6i6srVQ9LQV039G6k1vXfGWkkJhO4+paQjo06nXXo066vGFP40z3JgTRNAHccZpZIqlk0 X-Received: from irogers.svl.corp.google.com ([2620:15c:2a3:200:4ff1:8af6:9e1a:6382]) (user=irogers job=sendgmr) by 2002:a25:d8d3:0:b0:dcc:4785:b51e with SMTP id p202-20020a25d8d3000000b00dcc4785b51emr54008ybg.12.1709071331258; Tue, 27 Feb 2024 14:02:11 -0800 (PST) Date: Tue, 27 Feb 2024 14:01:48 -0800 In-Reply-To: <20240227220150.3876198-1-irogers@google.com> Message-Id: <20240227220150.3876198-5-irogers@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20240227220150.3876198-1-irogers@google.com> X-Mailer: git-send-email 2.44.0.rc1.240.g4c46232300-goog Subject: [PATCH v2 4/6] perf threads: Move threads to its own files From: Ian Rogers To: Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Namhyung Kim , Mark Rutland , Alexander Shishkin , Jiri Olsa , Ian Rogers , Adrian Hunter , Kan Liang , Oliver Upton , Yang Jihong , linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, bpf@vger.kernel.org Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Move threads out of machine and move thread_rb_node into the C file. This hides the implementation of threads from the rest of the code allowing for it to be refactored. Note, the implementation here is removed in the next patch in the series which moves to a hashtable. Locking discipline is tightened up in this change. When a function is added to threads.c care is taken that the threads lock is held appropriately. This replaces somewhat adhoc use of the lock in machine, and adds the lock in places it was missed primarily threads__nr. In the previous code it was the caller's responsibility to hold the right lock before calling an internal "__" version of the function. As the lock is now encapsulated in threads, the findnew function requires holding it (as it already did in machine). Rather than do conditionals with locks based on whether the thread should be created (which could potentially be error prone with a read lock match with a write unlock), have a separate threads__find that won't create the thread and only holds the read lock. This effectively duplicates the findnew logic, with the existing findnew logic only operating under a write lock assuming creation is necessary as a previous find failed. The creation may still fail with the write lock due to another thread. The duplication is removed in the next patch that delegates the implementation to hashtable. Signed-off-by: Ian Rogers --- tools/perf/util/Build | 1 + tools/perf/util/bpf_lock_contention.c | 8 +- tools/perf/util/machine.c | 287 ++++---------------------- tools/perf/util/machine.h | 20 +- tools/perf/util/thread.c | 2 +- tools/perf/util/thread.h | 6 - tools/perf/util/threads.c | 244 ++++++++++++++++++++++ tools/perf/util/threads.h | 35 ++++ 8 files changed, 325 insertions(+), 278 deletions(-) create mode 100644 tools/perf/util/threads.c create mode 100644 tools/perf/util/threads.h diff --git a/tools/perf/util/Build b/tools/perf/util/Build index 2cbeeb79b6ef..e0a723e24503 100644 --- a/tools/perf/util/Build +++ b/tools/perf/util/Build @@ -72,6 +72,7 @@ perf-y +=3D ordered-events.o perf-y +=3D namespaces.o perf-y +=3D comm.o perf-y +=3D thread.o +perf-y +=3D threads.o perf-y +=3D thread_map.o perf-y +=3D parse-events-flex.o perf-y +=3D parse-events-bison.o diff --git a/tools/perf/util/bpf_lock_contention.c b/tools/perf/util/bpf_lo= ck_contention.c index 31ff19afc20c..3992c8a9fd96 100644 --- a/tools/perf/util/bpf_lock_contention.c +++ b/tools/perf/util/bpf_lock_contention.c @@ -210,7 +210,7 @@ static const char *lock_contention_get_name(struct lock= _contention *con, =20 /* do not update idle comm which contains CPU number */ if (pid) { - struct thread *t =3D __machine__findnew_thread(machine, /*pid=3D*/-1, p= id); + struct thread *t =3D machine__findnew_thread(machine, /*pid=3D*/-1, pid= ); =20 if (t =3D=3D NULL) return name; @@ -302,9 +302,9 @@ int lock_contention_read(struct lock_contention *con) return -1; =20 if (con->aggr_mode =3D=3D LOCK_AGGR_TASK) { - struct thread *idle =3D __machine__findnew_thread(machine, - /*pid=3D*/0, - /*tid=3D*/0); + struct thread *idle =3D machine__findnew_thread(machine, + /*pid=3D*/0, + /*tid=3D*/0); thread__set_comm(idle, "swapper", /*timestamp=3D*/0); } =20 diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c index e072b2115b64..e668a97255f8 100644 --- a/tools/perf/util/machine.c +++ b/tools/perf/util/machine.c @@ -43,9 +43,6 @@ #include #include =20 -static void __machine__remove_thread(struct machine *machine, struct threa= d_rb_node *nd, - struct thread *th, bool lock); - static struct dso *machine__kernel_dso(struct machine *machine) { return map__dso(machine->vmlinux_map); @@ -58,35 +55,6 @@ static void dsos__init(struct dsos *dsos) init_rwsem(&dsos->lock); } =20 -static void machine__threads_init(struct machine *machine) -{ - int i; - - for (i =3D 0; i < THREADS__TABLE_SIZE; i++) { - struct threads *threads =3D &machine->threads[i]; - threads->entries =3D RB_ROOT_CACHED; - init_rwsem(&threads->lock); - threads->nr =3D 0; - threads->last_match =3D NULL; - } -} - -static int thread_rb_node__cmp_tid(const void *key, const struct rb_node *= nd) -{ - int to_find =3D (int) *((pid_t *)key); - - return to_find - (int)thread__tid(rb_entry(nd, struct thread_rb_node, rb_= node)->thread); -} - -static struct thread_rb_node *thread_rb_node__find(const struct thread *th, - struct rb_root *tree) -{ - pid_t to_find =3D thread__tid(th); - struct rb_node *nd =3D rb_find(&to_find, tree, thread_rb_node__cmp_tid); - - return rb_entry(nd, struct thread_rb_node, rb_node); -} - static int machine__set_mmap_name(struct machine *machine) { if (machine__is_host(machine)) @@ -120,7 +88,7 @@ int machine__init(struct machine *machine, const char *r= oot_dir, pid_t pid) RB_CLEAR_NODE(&machine->rb_node); dsos__init(&machine->dsos); =20 - machine__threads_init(machine); + threads__init(&machine->threads); =20 machine->vdso_info =3D NULL; machine->env =3D NULL; @@ -221,27 +189,11 @@ static void dsos__exit(struct dsos *dsos) =20 void machine__delete_threads(struct machine *machine) { - struct rb_node *nd; - int i; - - for (i =3D 0; i < THREADS__TABLE_SIZE; i++) { - struct threads *threads =3D &machine->threads[i]; - down_write(&threads->lock); - nd =3D rb_first_cached(&threads->entries); - while (nd) { - struct thread_rb_node *trb =3D rb_entry(nd, struct thread_rb_node, rb_n= ode); - - nd =3D rb_next(nd); - __machine__remove_thread(machine, trb, trb->thread, false); - } - up_write(&threads->lock); - } + threads__remove_all_threads(&machine->threads); } =20 void machine__exit(struct machine *machine) { - int i; - if (machine =3D=3D NULL) return; =20 @@ -254,12 +206,7 @@ void machine__exit(struct machine *machine) zfree(&machine->current_tid); zfree(&machine->kallsyms_filename); =20 - machine__delete_threads(machine); - for (i =3D 0; i < THREADS__TABLE_SIZE; i++) { - struct threads *threads =3D &machine->threads[i]; - - exit_rwsem(&threads->lock); - } + threads__exit(&machine->threads); } =20 void machine__delete(struct machine *machine) @@ -526,7 +473,7 @@ static void machine__update_thread_pid(struct machine *= machine, if (thread__pid(th) =3D=3D thread__tid(th)) return; =20 - leader =3D __machine__findnew_thread(machine, thread__pid(th), thread__pi= d(th)); + leader =3D machine__findnew_thread(machine, thread__pid(th), thread__pid(= th)); if (!leader) goto out_err; =20 @@ -560,160 +507,55 @@ static void machine__update_thread_pid(struct machin= e *machine, goto out_put; } =20 -/* - * Front-end cache - TID lookups come in blocks, - * so most of the time we dont have to look up - * the full rbtree: - */ -static struct thread* -__threads__get_last_match(struct threads *threads, struct machine *machine, - int pid, int tid) -{ - struct thread *th; - - th =3D threads->last_match; - if (th !=3D NULL) { - if (thread__tid(th) =3D=3D tid) { - machine__update_thread_pid(machine, th, pid); - return thread__get(th); - } - thread__put(threads->last_match); - threads->last_match =3D NULL; - } - - return NULL; -} - -static struct thread* -threads__get_last_match(struct threads *threads, struct machine *machine, - int pid, int tid) -{ - struct thread *th =3D NULL; - - if (perf_singlethreaded) - th =3D __threads__get_last_match(threads, machine, pid, tid); - - return th; -} - -static void -__threads__set_last_match(struct threads *threads, struct thread *th) -{ - thread__put(threads->last_match); - threads->last_match =3D thread__get(th); -} - -static void -threads__set_last_match(struct threads *threads, struct thread *th) -{ - if (perf_singlethreaded) - __threads__set_last_match(threads, th); -} - /* * Caller must eventually drop thread->refcnt returned with a successful * lookup/new thread inserted. */ -static struct thread *____machine__findnew_thread(struct machine *machine, - struct threads *threads, - pid_t pid, pid_t tid, - bool create) +static struct thread *__machine__findnew_thread(struct machine *machine, + pid_t pid, + pid_t tid, + bool create) { - struct rb_node **p =3D &threads->entries.rb_root.rb_node; - struct rb_node *parent =3D NULL; - struct thread *th; - struct thread_rb_node *nd; - bool leftmost =3D true; + struct thread *th =3D threads__find(&machine->threads, tid); + bool created; =20 - th =3D threads__get_last_match(threads, machine, pid, tid); - if (th) + if (th) { + machine__update_thread_pid(machine, th, pid); return th; - - while (*p !=3D NULL) { - parent =3D *p; - th =3D rb_entry(parent, struct thread_rb_node, rb_node)->thread; - - if (thread__tid(th) =3D=3D tid) { - threads__set_last_match(threads, th); - machine__update_thread_pid(machine, th, pid); - return thread__get(th); - } - - if (tid < thread__tid(th)) - p =3D &(*p)->rb_left; - else { - p =3D &(*p)->rb_right; - leftmost =3D false; - } } - if (!create) return NULL; =20 - th =3D thread__new(pid, tid); - if (th =3D=3D NULL) - return NULL; - - nd =3D malloc(sizeof(*nd)); - if (nd =3D=3D NULL) { - thread__put(th); - return NULL; - } - nd->thread =3D th; - - rb_link_node(&nd->rb_node, parent, p); - rb_insert_color_cached(&nd->rb_node, &threads->entries, leftmost); - /* - * We have to initialize maps separately after rb tree is updated. - * - * The reason is that we call machine__findnew_thread within - * thread__init_maps to find the thread leader and that would screwed - * the rb tree. - */ - if (thread__init_maps(th, machine)) { - pr_err("Thread init failed thread %d\n", pid); - rb_erase_cached(&nd->rb_node, &threads->entries); - RB_CLEAR_NODE(&nd->rb_node); - free(nd); - thread__put(th); - return NULL; - } - /* - * It is now in the rbtree, get a ref - */ - threads__set_last_match(threads, th); - ++threads->nr; - - return thread__get(th); -} + th =3D threads__findnew(&machine->threads, pid, tid, &created); + if (created) { + /* + * We have to initialize maps separately after rb tree is + * updated. + * + * The reason is that we call machine__findnew_thread within + * thread__init_maps to find the thread leader and that would + * screwed the rb tree. + */ + if (thread__init_maps(th, machine)) { + pr_err("Thread init failed thread %d\n", pid); + threads__remove(&machine->threads, th); + thread__put(th); + return NULL; + } + } else + machine__update_thread_pid(machine, th, pid); =20 -struct thread *__machine__findnew_thread(struct machine *machine, pid_t pi= d, pid_t tid) -{ - return ____machine__findnew_thread(machine, machine__threads(machine, tid= ), pid, tid, true); + return th; } =20 -struct thread *machine__findnew_thread(struct machine *machine, pid_t pid, - pid_t tid) +struct thread *machine__findnew_thread(struct machine *machine, pid_t pid,= pid_t tid) { - struct threads *threads =3D machine__threads(machine, tid); - struct thread *th; - - down_write(&threads->lock); - th =3D __machine__findnew_thread(machine, pid, tid); - up_write(&threads->lock); - return th; + return __machine__findnew_thread(machine, pid, tid, /*create=3D*/true); } =20 -struct thread *machine__find_thread(struct machine *machine, pid_t pid, - pid_t tid) +struct thread *machine__find_thread(struct machine *machine, pid_t pid, pi= d_t tid) { - struct threads *threads =3D machine__threads(machine, tid); - struct thread *th; - - down_read(&threads->lock); - th =3D ____machine__findnew_thread(machine, threads, pid, tid, false); - up_read(&threads->lock); - return th; + return __machine__findnew_thread(machine, pid, tid, /*create=3D*/false); } =20 /* @@ -1127,23 +969,13 @@ static int machine_fprintf_cb(struct thread *thread,= void *data) return 0; } =20 -static size_t machine__threads_nr(const struct machine *machine) -{ - size_t nr =3D 0; - - for (int i =3D 0; i < THREADS__TABLE_SIZE; i++) - nr +=3D machine->threads[i].nr; - - return nr; -} - size_t machine__fprintf(struct machine *machine, FILE *fp) { struct machine_fprintf_cb_args args =3D { .fp =3D fp, .printed =3D 0, }; - size_t ret =3D fprintf(fp, "Threads: %zu\n", machine__threads_nr(machine)= ); + size_t ret =3D fprintf(fp, "Threads: %zu\n", threads__nr(&machine->thread= s)); =20 machine__for_each_thread(machine, machine_fprintf_cb, &args); return ret + args.printed; @@ -2069,36 +1901,9 @@ int machine__process_mmap_event(struct machine *mach= ine, union perf_event *event return 0; } =20 -static void __machine__remove_thread(struct machine *machine, struct threa= d_rb_node *nd, - struct thread *th, bool lock) -{ - struct threads *threads =3D machine__threads(machine, thread__tid(th)); - - if (!nd) - nd =3D thread_rb_node__find(th, &threads->entries.rb_root); - - if (threads->last_match && RC_CHK_EQUAL(threads->last_match, th)) - threads__set_last_match(threads, NULL); - - if (lock) - down_write(&threads->lock); - - BUG_ON(refcount_read(thread__refcnt(th)) =3D=3D 0); - - thread__put(nd->thread); - rb_erase_cached(&nd->rb_node, &threads->entries); - RB_CLEAR_NODE(&nd->rb_node); - --threads->nr; - - free(nd); - - if (lock) - up_write(&threads->lock); -} - void machine__remove_thread(struct machine *machine, struct thread *th) { - return __machine__remove_thread(machine, NULL, th, true); + return threads__remove(&machine->threads, th); } =20 int machine__process_fork_event(struct machine *machine, union perf_event = *event, @@ -3232,23 +3037,7 @@ int machine__for_each_thread(struct machine *machine, int (*fn)(struct thread *thread, void *p), void *priv) { - struct threads *threads; - struct rb_node *nd; - int rc =3D 0; - int i; - - for (i =3D 0; i < THREADS__TABLE_SIZE; i++) { - threads =3D &machine->threads[i]; - for (nd =3D rb_first_cached(&threads->entries); nd; - nd =3D rb_next(nd)) { - struct thread_rb_node *trb =3D rb_entry(nd, struct thread_rb_node, rb_n= ode); - - rc =3D fn(trb->thread, priv); - if (rc !=3D 0) - return rc; - } - } - return rc; + return threads__for_each_thread(&machine->threads, fn, priv); } =20 int machines__for_each_thread(struct machines *machines, diff --git a/tools/perf/util/machine.h b/tools/perf/util/machine.h index b738ce84817b..e28c787616fe 100644 --- a/tools/perf/util/machine.h +++ b/tools/perf/util/machine.h @@ -7,6 +7,7 @@ #include "maps.h" #include "dsos.h" #include "rwsem.h" +#include "threads.h" =20 struct addr_location; struct branch_stack; @@ -28,16 +29,6 @@ extern const char *ref_reloc_sym_names[]; =20 struct vdso_info; =20 -#define THREADS__TABLE_BITS 8 -#define THREADS__TABLE_SIZE (1 << THREADS__TABLE_BITS) - -struct threads { - struct rb_root_cached entries; - struct rw_semaphore lock; - unsigned int nr; - struct thread *last_match; -}; - struct machine { struct rb_node rb_node; pid_t pid; @@ -48,7 +39,7 @@ struct machine { char *root_dir; char *mmap_name; char *kallsyms_filename; - struct threads threads[THREADS__TABLE_SIZE]; + struct threads threads; struct vdso_info *vdso_info; struct perf_env *env; struct dsos dsos; @@ -69,12 +60,6 @@ struct machine { bool trampolines_mapped; }; =20 -static inline struct threads *machine__threads(struct machine *machine, pi= d_t tid) -{ - /* Cast it to handle tid =3D=3D -1 */ - return &machine->threads[(unsigned int)tid % THREADS__TABLE_SIZE]; -} - /* * The main kernel (vmlinux) map */ @@ -220,7 +205,6 @@ bool machine__is(struct machine *machine, const char *a= rch); bool machine__normalized_is(struct machine *machine, const char *arch); int machine__nr_cpus_avail(struct machine *machine); =20 -struct thread *__machine__findnew_thread(struct machine *machine, pid_t pi= d, pid_t tid); struct thread *machine__findnew_thread(struct machine *machine, pid_t pid,= pid_t tid); =20 struct dso *machine__findnew_dso_id(struct machine *machine, const char *f= ilename, struct dso_id *id); diff --git a/tools/perf/util/thread.c b/tools/perf/util/thread.c index c59ab4d79163..1aa8962dcf52 100644 --- a/tools/perf/util/thread.c +++ b/tools/perf/util/thread.c @@ -26,7 +26,7 @@ int thread__init_maps(struct thread *thread, struct machi= ne *machine) if (pid =3D=3D thread__tid(thread) || pid =3D=3D -1) { thread__set_maps(thread, maps__new(machine)); } else { - struct thread *leader =3D __machine__findnew_thread(machine, pid, pid); + struct thread *leader =3D machine__findnew_thread(machine, pid, pid); =20 if (leader) { thread__set_maps(thread, maps__get(thread__maps(leader))); diff --git a/tools/perf/util/thread.h b/tools/perf/util/thread.h index df344262eaee..8b4a3c69bad1 100644 --- a/tools/perf/util/thread.h +++ b/tools/perf/util/thread.h @@ -3,7 +3,6 @@ #define __PERF_THREAD_H =20 #include -#include #include #include #include @@ -29,11 +28,6 @@ struct lbr_stitch { struct callchain_cursor_node *prev_lbr_cursor; }; =20 -struct thread_rb_node { - struct rb_node rb_node; - struct thread *thread; -}; - DECLARE_RC_STRUCT(thread) { /** @maps: mmaps associated with this thread. */ struct maps *maps; diff --git a/tools/perf/util/threads.c b/tools/perf/util/threads.c new file mode 100644 index 000000000000..d984ec939c7b --- /dev/null +++ b/tools/perf/util/threads.c @@ -0,0 +1,244 @@ +// SPDX-License-Identifier: GPL-2.0 +#include "threads.h" +#include "machine.h" +#include "thread.h" + +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]; +} + +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]; + + table->entries =3D RB_ROOT_CACHED; + init_rwsem(&table->lock); + table->nr =3D 0; + table->last_match =3D NULL; + } +} + +void threads__exit(struct threads *threads) +{ + threads__remove_all_threads(threads); + for (int i =3D 0; i < THREADS__TABLE_SIZE; i++) { + struct threads_table_entry *table =3D &threads->table[i]; + + exit_rwsem(&table->lock); + } +} + +size_t threads__nr(struct threads *threads) +{ + size_t nr =3D 0; + + for (int i =3D 0; i < THREADS__TABLE_SIZE; i++) { + struct threads_table_entry *table =3D &threads->table[i]; + + down_read(&table->lock); + nr +=3D table->nr; + up_read(&table->lock); + } + return nr; +} + +/* + * Front-end cache - TID lookups come in blocks, + * so most of the time we dont have to look up + * the full rbtree: + */ +static struct thread *__threads_table_entry__get_last_match(struct threads= _table_entry *table, + pid_t tid) +{ + struct thread *th, *res =3D NULL; + + th =3D table->last_match; + if (th !=3D NULL) { + if (thread__tid(th) =3D=3D tid) + res =3D thread__get(th); + } + return res; +} + +static void __threads_table_entry__set_last_match(struct threads_table_ent= ry *table, + struct thread *th) +{ + thread__put(table->last_match); + table->last_match =3D thread__get(th); +} + +static void threads_table_entry__set_last_match(struct threads_table_entry= *table, + struct thread *th) +{ + down_write(&table->lock); + __threads_table_entry__set_last_match(table, th); + up_write(&table->lock); +} + +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; + + 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; + } + up_read(&table->lock); + if (res) + threads_table_entry__set_last_match(table, res); + return res; +} + +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; + + *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); + } +out_unlock: + up_write(&table->lock); + return res; +} + +void threads__remove_all_threads(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; + + 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; + + free(trb); + } + assert(table->nr =3D=3D 0); + up_write(&table->lock); + } +} + +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); + + down_write(&table->lock); + if (table->last_match && RC_CHK_EQUAL(table->last_match, thread)) + __threads_table_entry__set_last_match(table, NULL); + + 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; + } + up_write(&table->lock); +} + +int threads__for_each_thread(struct threads *threads, + int (*fn)(struct thread *thread, void *data), + void *data) +{ + for (int i =3D 0; i < THREADS__TABLE_SIZE; i++) { + struct threads_table_entry *table =3D &threads->table[i]; + struct rb_node *nd; + + 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); + + if (rc !=3D 0) + return rc; + } + } + return 0; + +} diff --git a/tools/perf/util/threads.h b/tools/perf/util/threads.h new file mode 100644 index 000000000000..ed67de627578 --- /dev/null +++ b/tools/perf/util/threads.h @@ -0,0 +1,35 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef __PERF_THREADS_H +#define __PERF_THREADS_H + +#include +#include "rwsem.h" + +struct thread; + +#define THREADS__TABLE_BITS 8 +#define THREADS__TABLE_SIZE (1 << THREADS__TABLE_BITS) + +struct threads_table_entry { + struct rb_root_cached entries; + struct rw_semaphore lock; + unsigned int nr; + struct thread *last_match; +}; + +struct threads { + struct threads_table_entry table[THREADS__TABLE_SIZE]; +}; + +void threads__init(struct threads *threads); +void threads__exit(struct threads *threads); +size_t threads__nr(struct threads *threads); +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); +void threads__remove_all_threads(struct threads *threads); +void threads__remove(struct threads *threads, struct thread *thread); +int threads__for_each_thread(struct threads *threads, + int (*fn)(struct thread *thread, void *data), + void *data); + +#endif /* __PERF_THREADS_H */ --=20 2.44.0.rc1.240.g4c46232300-goog From nobody Sat Feb 7 17:42:12 2026 Received: from mail-yw1-f202.google.com (mail-yw1-f202.google.com [209.85.128.202]) (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 4CFD4157E65 for ; Tue, 27 Feb 2024 22:02:14 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.128.202 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709071338; cv=none; b=lvBCPy6LOtkiIKApHm3/+EO+5vX3+aEg0K2s2Jlhh+18x2T01/nYt67qSFDkiVmYQMIyaSrSPOZdI3rI1kxA1UrSd2hKnICV78CcevLeVAI9B+RgzhpM9hqtjFaY7MTAHO/YgZvKEggPfYwM95dEZ24Drbc1YnzC690+BhwH2so= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709071338; c=relaxed/simple; bh=8uQDXFmaIiRJ6Hg6w6jtncylaSx91Lkrl/drWddSSDA=; h=Date:In-Reply-To:Message-Id:Mime-Version:References:Subject:From: To:Content-Type; b=QYdjyO4yj/oPwRKxavFuCnrjj8dfXiQAJLHDnj6XnKmbGvmQlbP7xyXXKKiO4oBComBJAb8icv081mz/Obew9uMwiPB7WosgG4g+ggTcmz4YLZ7pKz7HYjB7dGYVy+4OtYyTwUqBzSyZzmI6e5wlxRcqsFtOqkuqbxgBZuDBc5M= 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=GVYTn6Tx; arc=none smtp.client-ip=209.85.128.202 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="GVYTn6Tx" Received: by mail-yw1-f202.google.com with SMTP id 00721157ae682-608b648044fso88532087b3.3 for ; Tue, 27 Feb 2024 14:02:14 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1709071333; x=1709676133; 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=wba+QvoL7K11DwHxYWfqulLAN6tkIyxzlgcJ5v9C6VE=; b=GVYTn6TxJEypgiw8cYUM50IdLB0JV+gqF6e3HhFkS6L8+C1MR/h0xe1zfanAkOhtej /RKnakt//SLyy41x1YK/XOkYUP0Y5UQm6gOqIwL7r6jt0u1dXyFli6kENjVnjDTUmcQz 6tov3X9oh+Jn+N3XfWdZg3DorBO8oFSadTK4L6pQ7dFaFwBkwHW40astGgPXLqHDzaQE qSiGmpFNd8A1tBq3yjzG20eJ4nKmtpvjdTty4iR1zy8OmnYotXCKRi4IRFgyMTg+JXP3 VbrOmtHR+6gqVlnlDJuugOuqYixjYrJ4uvHei3NF3Pq6fe0STYgG6agjeMH2pDN3wJ71 Tg7w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1709071333; x=1709676133; 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=wba+QvoL7K11DwHxYWfqulLAN6tkIyxzlgcJ5v9C6VE=; b=xKbKOt2Cl4PDBttCHjkYr/EorVkqAuTlm+U54yfyPuAED/q0+CEu9IR+SDCaK+6cML zj0DyTXPCQnXHYxKUAaREV48lknazUHCggDC5rbUIOSvaxeRvC1Kbpo4ho8Dk9J0WZRA 1ChwlPSm4iTOBqsg3/zIgB0m/UYbN2sdQ6y5ZBdfM1Y6ICfqr42IAOjhlXuVjFm+nERh 0Zr8oV5Urc85Qe8h6J3WmYfpfuhJAbCop3TMtJF+/O/rgGFqxuzZY99k5CyrtduDImTs PHNhtt0V3rwl8bePjiU7sWPxCbqSZ2umsQuiOQtosuH2whg779VrTTkqs3apVzH3VQZC 5+WA== X-Forwarded-Encrypted: i=1; AJvYcCWOFA3M7oRwg9gkTs/rDedynwAkD9tb0HpEcVqVp7AG6AxPG8OPDK7f9G3lrP/86U2G0a9e6tq+ssz/NrD78M092cE552xFVY1znLSW X-Gm-Message-State: AOJu0YzzBohq0yzOdn9irMdL8zZywj7W8z4TK2A5xVwjWRhTk30afiRh iihD1WdrtHHxw+9VPkqbHO22X8+5eEZBhRYF2Ax7e+tlT0xTTpOLBHTM591uLad68qA2hpbUS/N TZWhPsg== X-Google-Smtp-Source: AGHT+IG9T4R1x96rOSc+GuB8pVQ5WbQDpSUg8dTL0ZQ9ABn75erJ4LVziuD94ezEy2HRtYqUZJ3pa5OA7Cpe X-Received: from irogers.svl.corp.google.com ([2620:15c:2a3:200:4ff1:8af6:9e1a:6382]) (user=irogers job=sendgmr) by 2002:a81:6c56:0:b0:608:ba07:3093 with SMTP id h83-20020a816c56000000b00608ba073093mr780129ywc.1.1709071333554; Tue, 27 Feb 2024 14:02:13 -0800 (PST) Date: Tue, 27 Feb 2024 14:01:49 -0800 In-Reply-To: <20240227220150.3876198-1-irogers@google.com> Message-Id: <20240227220150.3876198-6-irogers@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20240227220150.3876198-1-irogers@google.com> X-Mailer: git-send-email 2.44.0.rc1.240.g4c46232300-goog Subject: [PATCH v2 5/6] 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 , Kan Liang , Oliver Upton , Yang Jihong , linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, bpf@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 2.44.0.rc1.240.g4c46232300-goog From nobody Sat Feb 7 17:42:12 2026 Received: from mail-yb1-f201.google.com (mail-yb1-f201.google.com [209.85.219.201]) (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 E2A421586D8 for ; Tue, 27 Feb 2024 22:02:16 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.219.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709071338; cv=none; b=lBKbvWSwESAOEvOaZtGEY4uhbbEtwudtfcPm2UrfdDdA7CzPB3BBBzPbzRje+T343GNSzHukU2madJN8cgJkf53+1VRL024+/dS5oIc6blsGBP7lgVOEEITjyIqbFeb84r61Rwszzmijxc5/rMclk7eeFn0PBrBgWNTkDrpEpYc= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709071338; c=relaxed/simple; bh=upLg+yhe8A2OZg6p8OFlrhH2yLDrE7BI//l8P1Vylms=; h=Date:In-Reply-To:Message-Id:Mime-Version:References:Subject:From: To:Content-Type; b=pqyLHTrrjGbQ00RchUxraYd6c6gAvL0DBjILF6gWxAlW2psDGK3kutau1ZdVPGmOTyE62sY5kb5IXMu8o1QdYrPhjhR8id/bYvWAzAnY5xqFxiZKiMDRvXpR+NCUT/lS+9sXL5r0O6PAUbhBqWHq3nBnvvM1Ae134HZ24IwzDCg= 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=s9gcvNa9; arc=none smtp.client-ip=209.85.219.201 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="s9gcvNa9" Received: by mail-yb1-f201.google.com with SMTP id 3f1490d57ef6-dc6b26ce0bbso9048506276.1 for ; Tue, 27 Feb 2024 14:02:16 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1709071336; x=1709676136; 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=vCV6R+NKRLMYoVC59mA+bYuzdEe0EtrTOitlrlnnMsA=; b=s9gcvNa9lW/PIzWihQTBqJP0VhTkZpQ2bDTsbEkPcpPLqGv6NTqfIF9gX+jC0MYySl osPkLoPBNizf3K41BZSSLigRaSaGT1Qgn9qYm59CQODGL5LG0zYf6iSoQuyc1c5XWaTT TGaQukHZ1EJmX6+JatByB8EPKyCCGxF/6W4NW2krDMsZyfSS0Puzq9ziNCM9koeX4+bd a3m6oPYQDeFKyHAykaE2jJN3Ub+EOmpJqxC+j5xjSvgVUIi+U8m0pv6MByvY5wiwAWxH thikawX9Nj/Nm83tyMYSPhDXLrrW1TrwDhQ0TjXJs84drugGC6t1l/sekw811eMQguc/ ZjEw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1709071336; x=1709676136; 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=vCV6R+NKRLMYoVC59mA+bYuzdEe0EtrTOitlrlnnMsA=; b=TuCGVLZGBMMjIzrwm5aTz8fvWfUzCGFDtb1tkLAQlyNJ9RgUitKxkxEFzhZ0zj8Zjb sW5hmNOJFx4PntZBuNqKFTSdg4G1TNDjFxqoGty2rjjo5gizHGiaizj+PJrMD8cLInjK C610vH0gbGU8cOxhPlZCjBbnbbdXCx5g3hVSejI2zVy1C7liUcpASJf4z40MiXVvUra8 nYETtHvchs1eL2ZjAJHO49SrG4TzA/eqnYL4qDMrdsu9+P0cWA8AjHQZGdlt26uTGJgI DDnvTq63LoQ2pVO0H2bxtGhUNJxVdBA76kQwZ8HceZm4P2S7LeZLsFndPOwx3MaAos/E RaSQ== X-Forwarded-Encrypted: i=1; AJvYcCXWGOFdr6iIIcn9SkUvWRCkzR7cn4SYo/p7nEDmG1QouUEADxUQMSPCqCLTEKIYKM1LKjekI34vBA85UpmrU1yniVp7/jNqO1zto6u3 X-Gm-Message-State: AOJu0YwXcQaVN8i6kAmF3TsrYyukjn3Pgnf8Nyy18E+r3cfU3k4uYtzC +xuOjoISYUNIfHiUAJVJ3UCoDrn9ty/PimqSK5NhcPYO5L3uJ963OqZS15mm+zM1BIK/k2PIW3j yO9ECGA== X-Google-Smtp-Source: AGHT+IGEhA+c0sAKulaM8RvsHp0DR9xq8SYgR2yBjBN+6kuK+8Tuz+x8EH8gmVr1C3hn6lBPKxh3uS12sCNZ X-Received: from irogers.svl.corp.google.com ([2620:15c:2a3:200:4ff1:8af6:9e1a:6382]) (user=irogers job=sendgmr) by 2002:a05:6902:1204:b0:dc6:cd85:bcd7 with SMTP id s4-20020a056902120400b00dc6cd85bcd7mr220673ybu.3.1709071335967; Tue, 27 Feb 2024 14:02:15 -0800 (PST) Date: Tue, 27 Feb 2024 14:01:50 -0800 In-Reply-To: <20240227220150.3876198-1-irogers@google.com> Message-Id: <20240227220150.3876198-7-irogers@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20240227220150.3876198-1-irogers@google.com> X-Mailer: git-send-email 2.44.0.rc1.240.g4c46232300-goog Subject: [PATCH v2 6/6] perf threads: Reduce table size from 256 to 8 From: Ian Rogers To: Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Namhyung Kim , Mark Rutland , Alexander Shishkin , Jiri Olsa , Ian Rogers , Adrian Hunter , Kan Liang , Oliver Upton , Yang Jihong , linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, bpf@vger.kernel.org Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" The threads data structure is an array of hashmaps, previously rbtrees. The two levels allows for a fixed outer array where access is guarded by rw_semaphores. Commit 91e467bc568f ("perf machine: Use hashtable for machine threads") sized the outer table at 256 entries to avoid future scalability problems, however, this means the threads struct is sized at 30,720 bytes. As the hashmaps allow O(1) access for the common find/insert/remove operations, lower the number of entries to 8. This reduces the size overhead to 960 bytes. Signed-off-by: Ian Rogers --- tools/perf/util/threads.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tools/perf/util/threads.h b/tools/perf/util/threads.h index d03bd91a7769..da68d2223f18 100644 --- a/tools/perf/util/threads.h +++ b/tools/perf/util/threads.h @@ -7,7 +7,7 @@ =20 struct thread; =20 -#define THREADS__TABLE_BITS 8 +#define THREADS__TABLE_BITS 3 #define THREADS__TABLE_SIZE (1 << THREADS__TABLE_BITS) =20 struct threads_table_entry { --=20 2.44.0.rc1.240.g4c46232300-goog