From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ua1-x933.google.com (mail-ua1-x933.google.com [IPv6:2607:f8b0:4864:20::933]) by sourceware.org (Postfix) with ESMTPS id 9A9C13857830 for ; Thu, 11 Nov 2021 14:17:14 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 9A9C13857830 Received: by mail-ua1-x933.google.com with SMTP id v3so12070272uam.10 for ; Thu, 11 Nov 2021 06:17:14 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:message-id:date:mime-version:user-agent:subject :content-language:to:cc:references:from:in-reply-to :content-transfer-encoding; bh=c6kln763/knHkaTnDw7bM6GS8KJx2Fm02s6NVeEfBuI=; b=LzhPVqgzRSl+FEm/RtqmAF6TXLrfVM/lwMiUXZGJ12mUuVwh0sw6tN+H7+YbMwjBzM d+5/3VUgQCOGl0OJ1KhlFfYCBRUzrhCR3DlNkvUwPtGcpshv1BgJhpgXZNNgnLFN5UgJ iiQi6o+gJhAlroCUtg9uuvnSVu316sXT/qBVZDSDRszU5PniqB6okccOOQz02IjUuU3W Q9w9lstJfjljEWXzG4qxjGCND5Pjyb30C19M6qOwKGMuOdRpiMDVg5Ba+YPwlq5xeWdg l+R6VxVcUfuC5V/0rFGANSnX4Dmg8r22ZLWqm2H2OzZhtCOXGj81a6y8heshjwm86bAx x9DQ== X-Gm-Message-State: AOAM533saaURYD8hkZP0AdqoUIR14FKIY5c1mTtYpawwh8f/3zdh6dvR WC9hQoHsRUnM53lX/LpRDiFR+g== X-Google-Smtp-Source: ABdhPJwTR7idM8PYZrBhZQ3L1dsxyZaozrFqypSIoJMjN5ezRV4J6s43KEwNyXCh3MDWE3oMZ0Q/Mw== X-Received: by 2002:a05:6102:e10:: with SMTP id o16mr11099787vst.5.1636640234140; Thu, 11 Nov 2021 06:17:14 -0800 (PST) Received: from ?IPV6:2804:431:c7cb:55a:48f2:1d0b:8ae8:643a? ([2804:431:c7cb:55a:48f2:1d0b:8ae8:643a]) by smtp.gmail.com with ESMTPSA id e13sm2074806vkd.21.2021.11.11.06.17.12 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 11 Nov 2021 06:17:13 -0800 (PST) Message-ID: <8dee4235-b730-dad4-6497-2ba13d9c4f8d@linaro.org> Date: Thu, 11 Nov 2021 11:17:11 -0300 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.2.1 Subject: Re: [PATCH 1/3] inet: Fix getnameinfo (NI_NOFQDN) race condition (BZ#28566) Content-Language: en-US To: Florian Weimer Cc: Adhemerval Zanella via Libc-alpha , leonardo.macchia@gmail.com References: <20211110185832.1931688-1-adhemerval.zanella@linaro.org> <20211110185832.1931688-2-adhemerval.zanella@linaro.org> <87r1bn150g.fsf@oldenburg.str.redhat.com> <27605b2b-cde0-9b1a-fc97-882d30e30b49@linaro.org> <87czn6yf0d.fsf@oldenburg.str.redhat.com> <87lf1uwzkr.fsf@oldenburg.str.redhat.com> From: Adhemerval Zanella In-Reply-To: <87lf1uwzkr.fsf@oldenburg.str.redhat.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Spam-Status: No, score=-8.8 required=5.0 tests=BAYES_00, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, NICE_REPLY_A, RCVD_IN_DNSWL_NONE, SPF_HELO_NONE, SPF_PASS, TXREP autolearn=ham autolearn_force=no version=3.4.4 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on server2.sourceware.org X-BeenThere: libc-alpha@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Libc-alpha mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 11 Nov 2021 14:17:16 -0000 On 11/11/2021 11:12, Florian Weimer wrote: > * Adhemerval Zanella: > >> I meant H.J internal lock optimization [1], where the lll_lock int this >> case will be mostly a relaxed load instead of a CAS (since once 'domain' >> is properly initialized, there is no need to take the lock). >> >> [1] https://sourceware.org/pipermail/libc-alpha/2021-November/132899.html > > It doesn't work this way. It still does a CAS. Yeah, it helps only on contended case. Do you think we need to keep the double-check optimization here?