From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-vk1-f171.google.com (mail-vk1-f171.google.com [209.85.221.171]) by sourceware.org (Postfix) with ESMTPS id 633243858C54 for ; Sat, 29 Apr 2023 15:34:17 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org 633243858C54 Authentication-Results: sourceware.org; dmarc=fail (p=none dis=none) header.from=opensuse.org Authentication-Results: sourceware.org; spf=none smtp.mailfrom=cristianrodriguez.net Received: by mail-vk1-f171.google.com with SMTP id 71dfb90a1353d-44ad8153552so76985e0c.0 for ; Sat, 29 Apr 2023 08:34:17 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1682782457; x=1685374457; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=JFi05zvg9ZmUHr2NEFwxvhtTC2Qg6xINYEw+MfNO05M=; b=AQ5T4zsGM8MUDxhZZ7hBgUFA5ApsXLas1+jhgV9Yc/Tzzy6uVRR5VOhi8Z9csMeG3u Z9TmffHSA0OioO8Gs7P7sBd+SDsT77n4ZKBFZuNu7rEOjk2ENghsbKeFAjRoUwYwOwuk qtvQHnLl8QFGcNmMjkoCZtxd/IfjypXLZ6Y+Mr4U6tzeiKScifapsKgB6ZpDQghlxxTm hPtvUY9gf5vlS4QgGFOUgXWQzWLJyZ7QvObu5RPkxofBa5gwEMjJRojKrNZHMwitwS9x bw9ltp86XDmN0IpEkH8yOXTyPvfsagJuS5kPHN/TP0wGBFrWXnhOfYWf13axpiZlp/M8 GemQ== X-Gm-Message-State: AC+VfDxrPYii0KDMkdS+dq/fOxba4qwmB2Vgek6Ok0Tx6knCQkj0R/c7 NtvMmHCmyj7Llyu+rpZr2u90cDyhbcHJI8+xir9QIRMmIgnQRyBKvrk= X-Google-Smtp-Source: ACHHUZ6CD/1RZSh9cW8fq+DN5bcvw6ZEdfgjLtKDGNBsUnJoFSktWCZSOC1Nx1X5HXH/RhUPoFWOUo6Bz9NMslbqqnQ= X-Received: by 2002:a1f:a60c:0:b0:443:ddfe:af5d with SMTP id p12-20020a1fa60c000000b00443ddfeaf5dmr2633610vke.0.1682782456883; Sat, 29 Apr 2023 08:34:16 -0700 (PDT) MIME-Version: 1.0 References: In-Reply-To: From: =?UTF-8?Q?Cristian_Rodr=C3=ADguez?= Date: Sat, 29 Apr 2023 11:34:05 -0400 Message-ID: Subject: Re: Use adaptive mutex with std::mutex To: Noah Goldstein Cc: "H.J. Lu" , GNU C Library Content-Type: multipart/alternative; boundary="00000000000093c3c605fa7b5244" X-Spam-Status: No, score=-1.0 required=5.0 tests=BAYES_00,HEADER_FROM_DIFFERENT_DOMAINS,HTML_MESSAGE,KAM_DMARC_NONE,KAM_DMARC_STATUS,KAM_LAZY_DOMAIN_SECURITY,RCVD_IN_DNSWL_NONE,RCVD_IN_MSPIKE_H2,SPF_HELO_NONE,SPF_NONE,TXREP,T_SCC_BODY_TEXT_LINE autolearn=no autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org List-Id: --00000000000093c3c605fa7b5244 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Wed, Apr 19, 2023 at 4:17=E2=80=AFPM Noah Goldstein via Libc-alpha < libc-alpha@sourceware.org> wrote: > On Tue, Apr 18, 2023 at 4:37=E2=80=AFPM H.J. Lu via Libc-alpha > wrote: > > i.e > Futex =3D O(10^4) cycles > Spin =3D O(10^2) cycles > > TIMED_NP Short Critical Section uses Futex: O(10^4) Cycles > TIMED_NP Long Critical Section uses futex: O(10^4) Cycles > > > ADAPTIVE_NP Short Critical Section uses spin: O(10^2) Cycles > ADAPTIVE_NP Long Critical Section uses spin + futex: O(10^2) + O(10^4) > =3D O(10^4) Cycles > > > If this is indeed the case.. Why is it not the default.. ? A quick read of docs says PTHREAD_MUTEX_INITIALIZER and PTHREAD_MUTEX_NORMAL are up to the implementation to choose.. --00000000000093c3c605fa7b5244--