From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from pegase2.c-s.fr (pegase2.c-s.fr [93.17.235.10]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 783351CCB43 for ; Wed, 4 Sep 2024 11:41:21 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=93.17.235.10 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1725450083; cv=none; b=Uc9iYsLOsnyrGqVb24cEiIFWeDyP+DnyUYG+gbwJ/260oCF8HGOEoCG0Tq6Eqq6kxHDg91j89T4ROMpMimO90gYs1YwEnnigGPrgwGYCARPDKZQZAEAwSveE/JZG7jHSRam97agHoLwiyiGNIevarn9SWCzdexZoVDB6Yd0F61M= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1725450083; c=relaxed/simple; bh=5U/sAfu6fDMYladg7S1N6V5lZi8WcZqMGbiIgzWx6P8=; h=Message-ID:Date:MIME-Version:To:Cc:From:Subject:Content-Type; b=iviN+sQyb1SdPpseumngeofGaVS4XImIXdOEu+HgnRCyILtE+wYEd929XzQ8bLBUxO35UrpLXCHmjpOOied0aB+XWlsOL6QkfpKQ5fhIwSVx1uSL7Aky16DMkTOu4dEynlhRhoz5LfxGFwSmyRjd3jdp83snvywBBWh15ZIdWH0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=csgroup.eu; spf=pass smtp.mailfrom=csgroup.eu; arc=none smtp.client-ip=93.17.235.10 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=csgroup.eu Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=csgroup.eu Received: from localhost (mailhub3.si.c-s.fr [172.26.127.67]) by localhost (Postfix) with ESMTP id 4WzLDH5M27z9sS7; Wed, 4 Sep 2024 13:41:19 +0200 (CEST) X-Virus-Scanned: amavisd-new at c-s.fr Received: from pegase2.c-s.fr ([172.26.127.65]) by localhost (pegase2.c-s.fr [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id AUxpvlBysyoS; Wed, 4 Sep 2024 13:41:19 +0200 (CEST) Received: from messagerie.si.c-s.fr (messagerie.si.c-s.fr [192.168.25.192]) by pegase2.c-s.fr (Postfix) with ESMTP id 4WzLDH4b6Gz9sRr; Wed, 4 Sep 2024 13:41:19 +0200 (CEST) Received: from localhost (localhost [127.0.0.1]) by messagerie.si.c-s.fr (Postfix) with ESMTP id 8E07B8B77A; Wed, 4 Sep 2024 13:41:19 +0200 (CEST) X-Virus-Scanned: amavisd-new at c-s.fr Received: from messagerie.si.c-s.fr ([127.0.0.1]) by localhost (messagerie.si.c-s.fr [127.0.0.1]) (amavisd-new, port 10023) with ESMTP id EpWSv8U77IeF; Wed, 4 Sep 2024 13:41:19 +0200 (CEST) Received: from [192.168.234.246] (unknown [192.168.234.246]) by messagerie.si.c-s.fr (Postfix) with ESMTP id 478688B778; Wed, 4 Sep 2024 13:41:19 +0200 (CEST) Message-ID: <30e9575c-a53e-4e17-bbbd-7127798efb05@csgroup.eu> Date: Wed, 4 Sep 2024 13:41:19 +0200 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Content-Language: fr-FR To: "Jason A. Donenfeld" , Adhemerval Zanella , Xi Ruoyao Cc: "linux-kernel@vger.kernel.org" , "linuxppc-dev@lists.ozlabs.org" From: Christophe Leroy Subject: Profiling of vdso_test_random Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Hi, I'm done a 'perf record' on vdso_test_random reduced to vdso test only, and I get the following function usage profile. Do you see the same type of percentage on your platforms ? I would have expected most of the time to be spent in __arch_chacha20_blocks_nostack() but that's in fact not the case. # Samples: 61K of event 'task-clock:ppp' # Event count (approx.): 15463500000 # # Overhead Command Shared Object Symbol # ........ ............... ................... .................................... # 57.74% vdso_test_getra [vdso] [.] __c_kernel_getrandom 22.49% vdso_test_getra [vdso] [.] __arch_chacha20_blocks_nostack 10.80% vdso_test_getra vdso_test_getrandom [.] test_vdso_getrandom 8.89% vdso_test_getra [vdso] [.] __kernel_getrandom 0.01% vdso_test_getra [kernel.kallsyms] [k] finish_task_switch.isra.0 Christophe