From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtp5-g21.free.fr (smtp5-g21.free.fr [212.27.42.5]) by sourceware.org (Postfix) with ESMTPS id 6C0DC3858C2C for ; Fri, 22 Apr 2022 13:30:26 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 6C0DC3858C2C Authentication-Results: sourceware.org; dmarc=none (p=none dis=none) header.from=opteya.com Authentication-Results: sourceware.org; spf=fail smtp.mailfrom=opteya.com Received: from [IPV6:2a01:e35:39f2:1220:a594:78ec:7cc0:11b3] (unknown [IPv6:2a01:e35:39f2:1220:a594:78ec:7cc0:11b3]) by smtp5-g21.free.fr (Postfix) with ESMTPS id EAAE15FF27; Fri, 22 Apr 2022 15:30:22 +0200 (CEST) Message-ID: <6d934a2c-8f89-50ca-11b8-e2eaeb046add@opteya.com> Date: Fri, 22 Apr 2022 15:30:22 +0200 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.7.0 Subject: Re: [PATCH v2] nptl: Add backoff mechanism to spinlock loop Content-Language: fr-FR To: Florian Weimer , Adhemerval Zanella via Libc-alpha Cc: Wangyang Guo References: <20220328084705.468207-1-wangyang.guo@intel.com> <97b1105f-42e8-a347-f82e-c81e548f0c2f@linaro.org> <82d5d195-aea0-f817-bfc1-5822829728c7@linaro.org> <87wnfufrh2.fsf@oldenburg.str.redhat.com> From: Yann Droneaud Organization: OPTEYA In-Reply-To: <87wnfufrh2.fsf@oldenburg.str.redhat.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-Spam-Status: No, score=-2.7 required=5.0 tests=BAYES_00, KAM_DMARC_STATUS, NICE_REPLY_A, RCVD_IN_DNSWL_NONE, SPF_HELO_NONE, SPF_SOFTFAIL, 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: Fri, 22 Apr 2022 13:30:27 -0000 Le 12/04/2022 à 13:53, Florian Weimer via Libc-alpha a écrit : > * Adhemerval Zanella via Libc-alpha: > >> On 30/03/2022 14:07, Noah Goldstein wrote: >>> What would be the best init jitter for arch w/ only syscall timers? TID? Or >>> something else? >> We don't cached the TID anymore, so it would still generate syscalls. > We do have the TID for the running process in the TCB. We need it (or > something like it) for recursive locks. > > Maybe for this application, we should use some number of upper bits from > a per-thread linear consequential generator, initialized to a random > value at thread start? As each running threads has its own stack, thread' stack address can be used as a seed for such PRNG. Regards. -- Yann Droneaud OPTEYA