From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 76C9C19FA8E; Thu, 5 Sep 2024 17:03:42 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1725555822; cv=none; b=cejyqbeVm++LFquUnjASNVhkf2FVyLmtrimG7QLBRGQudIUbMLIFVFsEex+N5AY+09g5BRQea7sRzmVgZXZHjw+9+jsSs7gSdlHIg3HGntDcuygMJjvsuyXRpgk/9wJxeALc4byXogbcfFJtkLvv8UDzzgA0307PtLsMAdNIwws= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1725555822; c=relaxed/simple; bh=nJr8UA9brtZt8MAxTeFaBGCFlqvqywHjYo6H6YDX4GQ=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=YUcaSXG1gngBBDadnmckMhgR90LhPNoagSM3HGMLETlN6JKkjUilO5mUwTS3bTO6K2DLS2w00b7B9fpUFJ/zHQPRc26Sgkzgcl9XGXfr8cr1QGQMGBDk7I6T9v16mwtYgzRcybh/KWmkDCzs9zdAiC3Q8dX7NWJ+PCwxS9MF+qc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=zx2c4.com header.i=@zx2c4.com header.b=S8oxi/AJ; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=zx2c4.com header.i=@zx2c4.com header.b="S8oxi/AJ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E2114C4CEC3; Thu, 5 Sep 2024 17:03:39 +0000 (UTC) Authentication-Results: smtp.kernel.org; dkim=pass (1024-bit key) header.d=zx2c4.com header.i=@zx2c4.com header.b="S8oxi/AJ" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=zx2c4.com; s=20210105; t=1725555817; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=2WPPczzM5fWySeHC6qCU5mJN44nYuMHACOhNso4EGCc=; b=S8oxi/AJO3vG5kC0wYzvPcvwfn+o0kCttzDIhQelVpgwHEjGgAUGSmBmhwbhPa1WeQUBkb zu10fm2SriimEK0oAC9nBbD2fdcQS3U5JLuIJ3Yt6a4wdt2cJhjM7HSPHPV5+s0R7BSnJa 90zYJO/+yld5Pdz8ajTRqlFukUnSKxg= Received: by mail.zx2c4.com (ZX2C4 Mail Server) with ESMTPSA id 27c37213 (TLSv1.3:TLS_AES_256_GCM_SHA384:256:NO); Thu, 5 Sep 2024 17:03:37 +0000 (UTC) Date: Thu, 5 Sep 2024 19:03:34 +0200 From: "Jason A. Donenfeld" To: Christophe Leroy 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 Subject: Re: [PATCH v5 4/5] powerpc/vdso: Wire up getrandom() vDSO implementation on VDSO32 Message-ID: References: <1f49c2ce009f8b007ab0676fb41187b2d54f28b2.1725304404.git.christophe.leroy@csgroup.eu> <85c02620-e8b2-4c97-9905-685a9a4e556d@csgroup.eu> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <85c02620-e8b2-4c97-9905-685a9a4e556d@csgroup.eu> On Thu, Sep 05, 2024 at 06:55:27PM +0200, Christophe Leroy wrote: > > > Le 05/09/2024 à 18:13, Jason A. Donenfeld a écrit : > >> +/* > >> + * The macro sets two stack frames, one for the caller and one for the callee > >> + * because there are no requirement for the caller to set a stack frame when > >> + * calling VDSO so it may have omitted to set one, especially on PPC64 > >> + */ > >> + > >> +.macro cvdso_call funct > >> + .cfi_startproc > >> + PPC_STLU r1, -PPC_MIN_STKFRM(r1) > >> + .cfi_adjust_cfa_offset PPC_MIN_STKFRM > >> + mflr r0 > >> + PPC_STLU r1, -PPC_MIN_STKFRM(r1) > >> + .cfi_adjust_cfa_offset PPC_MIN_STKFRM > >> + PPC_STL r0, PPC_MIN_STKFRM + PPC_LR_STKOFF(r1) > >> + .cfi_rel_offset lr, PPC_MIN_STKFRM + PPC_LR_STKOFF > >> + get_datapage r8 > >> + addi r8, r8, VDSO_RNG_DATA_OFFSET > >> + bl CFUNC(DOTSYM(\funct)) > >> + PPC_LL r0, PPC_MIN_STKFRM + PPC_LR_STKOFF(r1) > >> + cmpwi r3, 0 > >> + mtlr r0 > >> + addi r1, r1, 2 * PPC_MIN_STKFRM > >> + .cfi_restore lr > >> + .cfi_def_cfa_offset 0 > >> + crclr so > >> + bgelr+ > >> + crset so > >> + neg r3, r3 > >> + blr > >> + .cfi_endproc > >> +.endm > > > > You wrote in an earlier email that this worked with time namespaces, but > > in my testing that doesn't seem to be the case. > > Did I write that ? I can't remember and neither can I remember testing > it with time namespaces. It's possible I confused you with someone else? Hum. Anyway... > > From my test harness [1]: > > > > Normal single thread > > vdso: 25000000 times in 12.494133131 seconds > > libc: 25000000 times in 69.594625188 seconds > > syscall: 25000000 times in 67.349243972 seconds > > Time namespace single thread > > vdso: 25000000 times in 71.673057436 seconds > > libc: 25000000 times in 71.712774121 seconds > > syscall: 25000000 times in 66.902318080 seconds > > > > I'm seeing this on ppc, ppc64, and ppc64le. > > What is the command to use to test with time namespace ? Look at the C in the commit I linked.