From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.4 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 64049C433DF for ; Sun, 24 May 2020 10:21:48 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 298F22077D for ; Sun, 24 May 2020 10:21:48 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="KeSNC3yN" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 298F22077D Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:36280 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jcnlL-0005Vk-Al for qemu-devel@archiver.kernel.org; Sun, 24 May 2020 06:21:47 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:54678) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1jcnkl-000551-HT for qemu-devel@nongnu.org; Sun, 24 May 2020 06:21:11 -0400 Received: from us-smtp-delivery-1.mimecast.com ([207.211.31.120]:38249 helo=us-smtp-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1jcnkg-0001c1-MD for qemu-devel@nongnu.org; Sun, 24 May 2020 06:21:10 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1590315664; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:autocrypt:autocrypt; bh=AvnijKzGXQOW5GBXx+hJrxkJ7cEgN2jA8BnHoZAskOg=; b=KeSNC3yNNxzCAII1B6+ClqepA+Bp4nCCiCnLueBO/6zZQV2yY5qo7kd26vazZ3F2lCbe4k a8PvUDf62UgButjeav+0/SJ8F4C6M82zepgrxV31VksJ5S8q3BjnIF604vqNIr2xljW15r 7JtCF9h/aLbW79/L7LtREoRsk1jkK5Q= Received: from mail-wr1-f71.google.com (mail-wr1-f71.google.com [209.85.221.71]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-325-ngTVa8qVM1yBrDNcpegCjw-1; Sun, 24 May 2020 06:21:02 -0400 X-MC-Unique: ngTVa8qVM1yBrDNcpegCjw-1 Received: by mail-wr1-f71.google.com with SMTP id w4so1111174wrl.13 for ; Sun, 24 May 2020 03:21:02 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:autocrypt :message-id:date:user-agent:mime-version:in-reply-to :content-language:content-transfer-encoding; bh=AvnijKzGXQOW5GBXx+hJrxkJ7cEgN2jA8BnHoZAskOg=; b=PNDSJZUMMXbuBMjCigivzs1uqHyok5VH4yAILnxEDfmaJReF+K8nBi+8Ky2pnENktR T12W2CKdmv7+Zqw1TOK/yAtJx+mCk04K6l/5QQSIwZlOBNIpw69hry0Woenq181s+/G+ j4URczWp/OwXxxoAZ6p/mticMexmZENNF7O2nHjXRHsyylEJ2bVhg/9R4Cq6THRtZpMI u9xqSeCs6J/LtwKuzGcFpmbB6QbT4c3vmKF+x+WJnf4jgym4pDGbGKu98ufW742W7ThP kJh4pXi+R7iIWBxHh/4r+AcCljwdjvSfFvPo7KD3E4Spz9sIcaRxqICSefcq2LsRmtGL EhBw== X-Gm-Message-State: AOAM532qSf15P5Z9AdyJHzlvBjusTU7TLnBUAQlRuAswebuPTa0mVwOI NBFOwoAti1kun5N41L1uzy8uBYScdubZEIb2EhSk0zCgnWKRzb4iH+MST0HapWrSv9hJmTztCDI h5RzV4ApSRUU5oV4= X-Received: by 2002:a1c:22d7:: with SMTP id i206mr40836wmi.186.1590315661619; Sun, 24 May 2020 03:21:01 -0700 (PDT) X-Google-Smtp-Source: ABdhPJxF/dJegdiFcOF9B1TwSrG+vP41ME+XZPve1mpQBF4Imo6T+F3zsjFWHA4TWpPuaXSA6N3gGQ== X-Received: by 2002:a1c:22d7:: with SMTP id i206mr40822wmi.186.1590315661337; Sun, 24 May 2020 03:21:01 -0700 (PDT) Received: from [192.168.1.39] (17.red-88-21-202.staticip.rima-tde.net. [88.21.202.17]) by smtp.gmail.com with ESMTPSA id l204sm4721813wmf.19.2020.05.24.03.20.59 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Sun, 24 May 2020 03:21:00 -0700 (PDT) Subject: Re: [PATCH 02/19] cpu: convert queued work to a QSIMPLEQ To: Robert Foley , qemu-devel@nongnu.org References: <20200522160755.886-1-robert.foley@linaro.org> <20200522160755.886-3-robert.foley@linaro.org> From: =?UTF-8?Q?Philippe_Mathieu-Daud=c3=a9?= Autocrypt: addr=philmd@redhat.com; keydata= mQINBDXML8YBEADXCtUkDBKQvNsQA7sDpw6YLE/1tKHwm24A1au9Hfy/OFmkpzo+MD+dYc+7 bvnqWAeGweq2SDq8zbzFZ1gJBd6+e5v1a/UrTxvwBk51yEkadrpRbi+r2bDpTJwXc/uEtYAB GvsTZMtiQVA4kRID1KCdgLa3zztPLCj5H1VZhqZsiGvXa/nMIlhvacRXdbgllPPJ72cLUkXf z1Zu4AkEKpccZaJspmLWGSzGu6UTZ7UfVeR2Hcc2KI9oZB1qthmZ1+PZyGZ/Dy+z+zklC0xl XIpQPmnfy9+/1hj1LzJ+pe3HzEodtlVA+rdttSvA6nmHKIt8Ul6b/h1DFTmUT1lN1WbAGxmg CH1O26cz5nTrzdjoqC/b8PpZiT0kO5MKKgiu5S4PRIxW2+RA4H9nq7nztNZ1Y39bDpzwE5Sp bDHzd5owmLxMLZAINtCtQuRbSOcMjZlg4zohA9TQP9krGIk+qTR+H4CV22sWldSkVtsoTaA2 qNeSJhfHQY0TyQvFbqRsSNIe2gTDzzEQ8itsmdHHE/yzhcCVvlUzXhAT6pIN0OT+cdsTTfif MIcDboys92auTuJ7U+4jWF1+WUaJ8gDL69ThAsu7mGDBbm80P3vvUZ4fQM14NkxOnuGRrJxO qjWNJ2ZUxgyHAh5TCxMLKWZoL5hpnvx3dF3Ti9HW2dsUUWICSQARAQABtDJQaGlsaXBwZSBN YXRoaWV1LURhdWTDqSAoUGhpbCkgPHBoaWxtZEByZWRoYXQuY29tPokCVQQTAQgAPwIbDwYL CQgHAwIGFQgCCQoLBBYCAwECHgECF4AWIQSJweePYB7obIZ0lcuio/1u3q3A3gUCXsfWwAUJ KtymWgAKCRCio/1u3q3A3ircD/9Vjh3aFNJ3uF3hddeoFg1H038wZr/xi8/rX27M1Vj2j9VH 0B8Olp4KUQw/hyO6kUxqkoojmzRpmzvlpZ0cUiZJo2bQIWnvScyHxFCv33kHe+YEIqoJlaQc JfKYlbCoubz+02E2A6bFD9+BvCY0LBbEj5POwyKGiDMjHKCGuzSuDRbCn0Mz4kCa7nFMF5Jv piC+JemRdiBd6102ThqgIsyGEBXuf1sy0QIVyXgaqr9O2b/0VoXpQId7yY7OJuYYxs7kQoXI 6WzSMpmuXGkmfxOgbc/L6YbzB0JOriX0iRClxu4dEUg8Bs2pNnr6huY2Ft+qb41RzCJvvMyu gS32LfN0bTZ6Qm2A8ayMtUQgnwZDSO23OKgQWZVglGliY3ezHZ6lVwC24Vjkmq/2yBSLakZE 6DZUjZzCW1nvtRK05ebyK6tofRsx8xB8pL/kcBb9nCuh70aLR+5cmE41X4O+MVJbwfP5s/RW 9BFSL3qgXuXso/3XuWTQjJJGgKhB6xXjMmb1J4q/h5IuVV4juv1Fem9sfmyrh+Wi5V1IzKI7 RPJ3KVb937eBgSENk53P0gUorwzUcO+ASEo3Z1cBKkJSPigDbeEjVfXQMzNt0oDRzpQqH2vp apo2jHnidWt8BsckuWZpxcZ9+/9obQ55DyVQHGiTN39hkETy3Emdnz1JVHTU0Q== Message-ID: Date: Sun, 24 May 2020 12:20:58 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.5.0 MIME-Version: 1.0 In-Reply-To: <20200522160755.886-3-robert.foley@linaro.org> Content-Language: en-US X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Received-SPF: pass client-ip=207.211.31.120; envelope-from=philmd@redhat.com; helo=us-smtp-1.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/05/24 06:21:04 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] [fuzzy] X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H3=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_PASS=-0.001, URIBL_BLOCKED=0.001 autolearn=_AUTOLEARN X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: peter.puhov@linaro.org, cota@braap.org, alex.bennee@linaro.org Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On 5/22/20 6:07 PM, Robert Foley wrote: > From: "Emilio G. Cota" > > Instead of open-coding it. Please use a full sentence (repeating the patch subject): "Convert queued work to a QSIMPLEQ instead of open-coding it." (Not all email clients display the subject preceding the content). Otherwise: Reviewed-by: Philippe Mathieu-Daudé > > While at it, make sure that all accesses to the list are > performed while holding the list's lock. > > Reviewed-by: Richard Henderson > Reviewed-by: Alex Bennée > Signed-off-by: Emilio G. Cota > Signed-off-by: Robert Foley > --- > cpus-common.c | 25 ++++++++----------------- > cpus.c | 14 ++++++++++++-- > hw/core/cpu.c | 1 + > include/hw/core/cpu.h | 6 +++--- > 4 files changed, 24 insertions(+), 22 deletions(-) > > diff --git a/cpus-common.c b/cpus-common.c > index 55d5df8923..210fc7fc39 100644 > --- a/cpus-common.c > +++ b/cpus-common.c > @@ -97,7 +97,7 @@ void cpu_list_remove(CPUState *cpu) > } > > struct qemu_work_item { > - struct qemu_work_item *next; > + QSIMPLEQ_ENTRY(qemu_work_item) node; > run_on_cpu_func func; > run_on_cpu_data data; > bool free, exclusive, done; > @@ -106,13 +106,7 @@ struct qemu_work_item { > static void queue_work_on_cpu(CPUState *cpu, struct qemu_work_item *wi) > { > qemu_mutex_lock(&cpu->work_mutex); > - if (cpu->queued_work_first == NULL) { > - cpu->queued_work_first = wi; > - } else { > - cpu->queued_work_last->next = wi; > - } > - cpu->queued_work_last = wi; > - wi->next = NULL; > + QSIMPLEQ_INSERT_TAIL(&cpu->work_list, wi, node); > wi->done = false; > qemu_mutex_unlock(&cpu->work_mutex); > > @@ -306,17 +300,14 @@ void process_queued_cpu_work(CPUState *cpu) > { > struct qemu_work_item *wi; > > - if (cpu->queued_work_first == NULL) { > + qemu_mutex_lock(&cpu->work_mutex); > + if (QSIMPLEQ_EMPTY(&cpu->work_list)) { > + qemu_mutex_unlock(&cpu->work_mutex); > return; > } > - > - qemu_mutex_lock(&cpu->work_mutex); > - while (cpu->queued_work_first != NULL) { > - wi = cpu->queued_work_first; > - cpu->queued_work_first = wi->next; > - if (!cpu->queued_work_first) { > - cpu->queued_work_last = NULL; > - } > + while (!QSIMPLEQ_EMPTY(&cpu->work_list)) { > + wi = QSIMPLEQ_FIRST(&cpu->work_list); > + QSIMPLEQ_REMOVE_HEAD(&cpu->work_list, node); > qemu_mutex_unlock(&cpu->work_mutex); > if (wi->exclusive) { > /* Running work items outside the BQL avoids the following deadlock: > diff --git a/cpus.c b/cpus.c > index 5670c96bcf..af44027549 100644 > --- a/cpus.c > +++ b/cpus.c > @@ -97,9 +97,19 @@ bool cpu_is_stopped(CPUState *cpu) > return cpu->stopped || !runstate_is_running(); > } > > +static inline bool cpu_work_list_empty(CPUState *cpu) > +{ > + bool ret; > + > + qemu_mutex_lock(&cpu->work_mutex); > + ret = QSIMPLEQ_EMPTY(&cpu->work_list); > + qemu_mutex_unlock(&cpu->work_mutex); > + return ret; > +} > + > static bool cpu_thread_is_idle(CPUState *cpu) > { > - if (cpu->stop || cpu->queued_work_first) { > + if (cpu->stop || !cpu_work_list_empty(cpu)) { > return false; > } > if (cpu_is_stopped(cpu)) { > @@ -1498,7 +1508,7 @@ static void *qemu_tcg_rr_cpu_thread_fn(void *arg) > cpu = first_cpu; > } > > - while (cpu && !cpu->queued_work_first && !cpu->exit_request) { > + while (cpu && cpu_work_list_empty(cpu) && !cpu->exit_request) { > > atomic_mb_set(&tcg_current_rr_cpu, cpu); > current_cpu = cpu; > diff --git a/hw/core/cpu.c b/hw/core/cpu.c > index 5284d384fb..77703d62b7 100644 > --- a/hw/core/cpu.c > +++ b/hw/core/cpu.c > @@ -368,6 +368,7 @@ static void cpu_common_initfn(Object *obj) > cpu->nr_threads = 1; > > qemu_mutex_init(&cpu->work_mutex); > + QSIMPLEQ_INIT(&cpu->work_list); > QTAILQ_INIT(&cpu->breakpoints); > QTAILQ_INIT(&cpu->watchpoints); > > diff --git a/include/hw/core/cpu.h b/include/hw/core/cpu.h > index 07f7698155..d78ff1d165 100644 > --- a/include/hw/core/cpu.h > +++ b/include/hw/core/cpu.h > @@ -331,8 +331,8 @@ struct qemu_work_item; > * @opaque: User data. > * @mem_io_pc: Host Program Counter at which the memory was accessed. > * @kvm_fd: vCPU file descriptor for KVM. > - * @work_mutex: Lock to prevent multiple access to queued_work_*. > - * @queued_work_first: First asynchronous work pending. > + * @work_mutex: Lock to prevent multiple access to @work_list. > + * @work_list: List of pending asynchronous work. > * @trace_dstate_delayed: Delayed changes to trace_dstate (includes all changes > * to @trace_dstate). > * @trace_dstate: Dynamic tracing state of events for this vCPU (bitmask). > @@ -376,7 +376,7 @@ struct CPUState { > sigjmp_buf jmp_env; > > QemuMutex work_mutex; > - struct qemu_work_item *queued_work_first, *queued_work_last; > + QSIMPLEQ_HEAD(, qemu_work_item) work_list; > > CPUAddressSpace *cpu_ases; > int num_ases; >