From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pj1-x1034.google.com (mail-pj1-x1034.google.com [IPv6:2607:f8b0:4864:20::1034]) by sourceware.org (Postfix) with ESMTPS id 19046385780D for ; Mon, 28 Jun 2021 13:15:15 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 19046385780D Received: by mail-pj1-x1034.google.com with SMTP id z3-20020a17090a3983b029016bc232e40bso10411667pjb.4 for ; Mon, 28 Jun 2021 06:15:15 -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:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=Zue8ksxobG6vX4Lp1tMe10W67Pd9nW4tKGyrbZOnzNU=; b=S8iWYTDGIQEPJP2I4Etj2ksyiqvPOOns0xDyPWE+WYNU8KLSfpvOs93nkIUa3HxBgb d8txt6669TPvJBZxQxVFsxfqVTRHjutN256wG6vNfKWSMNhSCBEE8WaUn0wgmBUBWp/3 O6DNnkF00cRr3wUOqL47/k6LF3PnH1dmv0pgfQbUmqg4nQWnz+cAEw5s4OeX5E+0DiQi LQBE5o/b4nuisgmPsvtdGCzvC25imz6XygnPooLx5xQiXr8HGZD3iPAJE/yspHDsGSl+ npMhRujubbvUbjt+G+JeR/u2A17H++R9mp5gh2hPnf+lTu67rppdHZZSb+aXuacyp3Ci 5wtA== X-Gm-Message-State: AOAM530e2RLYHoLtGxklynpDxnJ+0EawO/I7UqDraQjFGNqZawY2B6AI 1dbJnWXZ5uiFLCs699C5sFQ+4Uli+MPmlQ== X-Google-Smtp-Source: ABdhPJwM7rhNvfzH1pEH0HFi+YRAzX8qDMzQgNrHt+NSgkxYs0IMJb1XZGZDh4dFCf8904GsZCZQ2g== X-Received: by 2002:a17:90a:a383:: with SMTP id x3mr32246177pjp.87.1624886113857; Mon, 28 Jun 2021 06:15:13 -0700 (PDT) Received: from [192.168.1.108] ([177.194.59.218]) by smtp.gmail.com with ESMTPSA id b70sm14430826pfb.183.2021.06.28.06.15.12 for (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 28 Jun 2021 06:15:13 -0700 (PDT) Subject: Re: [PATCH] AArch64: Add hp-timing.h To: libc-alpha@sourceware.org References: <87pmw6uw73.fsf@oldenburg.str.redhat.com> <87h7hiuu3d.fsf@oldenburg.str.redhat.com> <20210628114927.GM13058@arm.com> From: Adhemerval Zanella Message-ID: Date: Mon, 28 Jun 2021 10:15:11 -0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.11.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-Spam-Status: No, score=-6.3 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=3.4.2 X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) 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: Mon, 28 Jun 2021 13:15:16 -0000 On 28/06/2021 09:10, Wilco Dijkstra via Libc-alpha wrote: > Hi Szabolcs, > >> iirc linux devs asked that it is only used in vdso so >> that it is under the kernel's control in case there >> are implementation issues (vdso is easy to disable >> and on some system it got disabled for timer reasons). > > No, the kernel must still emulate cntvct_el0 in that case because of SBSA > which requires that the timer is always available. This is just as easy as > disabling vDSO - and we know this works and is surprisingly fast as I > mentioned. Any particular reason why you haven't enabled HP_TIMING_INLINE to 1?