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 B11C51D04A1 for ; Wed, 4 Sep 2024 14:36:18 +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=1725460580; cv=none; b=muypwSm+brZ9JrwQMIq4YXmcro1U0MQ+ujmTmy9ergt/b2+vdZOCRnyDsfDqwzvQdMGK3sKs4lRcC7ZwQ+NZzvJHQnj+/28lGx7nYEPG0vo066wtQrJKhY40qwf2ZAer7i2OJ6tODlwLNe2HwRoq9GmnotkCeveATH0GvHOg0iY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1725460580; c=relaxed/simple; bh=mrcpBZCNCDHUN8s1jct5aPcG3/C9zlzErsh6HAxxzVU=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=BU8tYwZgM1wUklcuv3/A8c4VzhyITPhDrbfGyCFB6rjXSk2/5T0+SqM91zUFZzrJEIR5yik7+v2B0WuSlygJFNmEsPMmo5iXXvLsIAJpyYaQV14Xv4/k+lyhZye3Rh079MiM3yFr4flWFvtPl5K9qVNv7viXyVY+aBq6JHOkMqw= 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 4WzQ685Z1lz9sS7; Wed, 4 Sep 2024 16:36:16 +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 j3Oi0qoOC3QN; Wed, 4 Sep 2024 16:36:16 +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 4WzQ684j7Sz9sRy; Wed, 4 Sep 2024 16:36:16 +0200 (CEST) Received: from localhost (localhost [127.0.0.1]) by messagerie.si.c-s.fr (Postfix) with ESMTP id 8DE208B77A; Wed, 4 Sep 2024 16:36:16 +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 MDg64KpQGgK2; Wed, 4 Sep 2024 16:36:16 +0200 (CEST) Received: from [192.168.234.246] (unknown [192.168.234.246]) by messagerie.si.c-s.fr (Postfix) with ESMTP id 9D5618B778; Wed, 4 Sep 2024 16:36:15 +0200 (CEST) Message-ID: <070a2aa1-a804-4124-ad89-c43e09dc3ded@csgroup.eu> Date: Wed, 4 Sep 2024 16:36:15 +0200 Precedence: bulk X-Mailing-List: llvm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v5 0/5] Wire up getrandom() vDSO implementation on powerpc To: "Jason A. Donenfeld" Cc: Andrew Morton , Steven Rostedt , Masami Hiramatsu , Mathieu Desnoyers , Michael Ellerman , Nicholas Piggin , Naveen N Rao , Nathan Chancellor , Nick Desaulniers , Bill Wendling , Justin Stitt , Shuah Khan , linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-kselftest@vger.kernel.org, llvm@lists.linux.dev, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-trace-kernel@vger.kernel.org, Adhemerval Zanella , Xi Ruoyao References: Content-Language: fr-FR From: Christophe Leroy In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Le 04/09/2024 à 16:16, Jason A. Donenfeld a écrit : > Hi Christophe, Michael, > > On Mon, Sep 02, 2024 at 09:17:17PM +0200, Christophe Leroy wrote: >> This series wires up getrandom() vDSO implementation on powerpc. >> >> Tested on PPC32 on real hardware. >> Tested on PPC64 (both BE and LE) on QEMU: >> >> Performance on powerpc 885: >> ~# ./vdso_test_getrandom bench-single >> vdso: 25000000 times in 62.938002291 seconds >> libc: 25000000 times in 535.581916866 seconds >> syscall: 25000000 times in 531.525042806 seconds >> >> Performance on powerpc 8321: >> ~# ./vdso_test_getrandom bench-single >> vdso: 25000000 times in 16.899318858 seconds >> libc: 25000000 times in 131.050596522 seconds >> syscall: 25000000 times in 129.794790389 seconds >> >> Performance on QEMU pseries: >> ~ # ./vdso_test_getrandom bench-single >> vdso: 25000000 times in 4.977777162 seconds >> libc: 25000000 times in 75.516749981 seconds >> syscall: 25000000 times in 86.842242014 seconds > > Looking good. I have no remaining nits on this patchset; it looks good > to me. > > A review from Michael would be nice though (in addition to the necessary > "Ack" I need to commit this to my tree), because there are a lot of PPC > particulars that I don't know enough about to review properly. For > example, you use -ffixed-r30 on PPC64. I'm sure there's a good reason > for this, but I don't know enough to assess it. And cvdso_call I have no > idea what's going on. Etc. You can learn a bit more about cvdso_call in commit ce7d8056e38b ("powerpc/vdso: Prepare for switching VDSO to generic C implementation.") About the fixed-r30, you can learn more in commit a88603f4b92e ("powerpc/vdso: Don't use r30 to avoid breaking Go lang") > > But anyway, awesome work, and I look forward to the final stretches. Thanks, looking forward to getting this series applied. Christophe