From owner-freebsd-current@freebsd.org Fri Mar 9 14:59:16 2018 Return-Path: Delivered-To: freebsd-current@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id BFC3CF2F2B6 for ; Fri, 9 Mar 2018 14:59:16 +0000 (UTC) (envelope-from carpeddiem@gmail.com) Received: from mail-it0-x236.google.com (mail-it0-x236.google.com [IPv6:2607:f8b0:4001:c0b::236]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G2" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 54C0A7AE70 for ; Fri, 9 Mar 2018 14:59:16 +0000 (UTC) (envelope-from carpeddiem@gmail.com) Received: by mail-it0-x236.google.com with SMTP id v194-v6so3165417itb.0 for ; Fri, 09 Mar 2018 06:59:16 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:sender:in-reply-to:references:from:date:message-id :subject:to:cc; bh=cD3lacMYZpQQI36g3p/XnD83QjUI9MtpKWOqo5wnVjs=; b=D6QvBfggJ8w7Qjr0rckbvAsKq4pT+/2VzzcQB6lVNNKIbwV2anoiXINTt1/abu7eew lFo+7R8W+w8MP2S2ZSkESqdXO3GFe60kRZYF6SnLMcQGwbk0UZ2xmqHiHeHCLpUJd0iX 4Hdq8Ge4KLgB3wCkz15UhQ/EjN9988FBw/4h1ZOwL/TGzc8+yXXurIYBbhI/n3XS9jRE CwLJfboLA1w4OrDbDbd0LCuYmJga+hsfXj037a+MIVyQkpI2wxmC46qbfq1MmVU4iUNy tAwhe/VNIgRuik16K3S/IV7dcJZ/hRcUrE59DL0K/c2H+zRLkza3+BigVOJex3NWoO2A bl1A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:sender:in-reply-to:references:from :date:message-id:subject:to:cc; bh=cD3lacMYZpQQI36g3p/XnD83QjUI9MtpKWOqo5wnVjs=; b=tgd5r4jtzJb+f4QF4YN5+22X2Xag1UqhtQynfYiwvYwMW2shVHT7Gi/pvRP3gSmMWy Ms4iGnKm9UGpV0KiI/ZuR56kepw5HA2JSSmn3+r7ZEs8WC+5cpEnFNIwxHWsYMUMEn9Y /oiVlz+OPx+Jj5NaucGtl+CswCol1LL9zljTcXPdVi/29wB6KzfXs/mPhn947gFSQRAw MPTJQxMm5Ob/xmkRLH6jFT2sLpiHtD1tvURprDtLUhDBqTvHEsq78t0KnVMJteaN0gA8 o+aoOvM8D+lJmcGIqCBsVkT6/L5XfCaFfcNhiLtdCn1SWc5mXm5dgh++EcZ1yahshFDP nplg== X-Gm-Message-State: AElRT7ED9MbwV4LHep3rY4cuGDFniUQW+vN8Gn1YJZKVNBs1Ua9voEA2 FgqaW2+bGlJuXjVAVmHNGGGn3/ebcnm6QR+CoC/YUQ== X-Google-Smtp-Source: AG47ELsF7RhCEJtgjIa7HgdZAFUWSNc37FoE5ec/fYVMoTbrxSWWVGTk3SlH7IdPJXGBybnPo4t6OLQP77ix3kzXJL0= X-Received: by 10.36.47.135 with SMTP id j129mr4050340itj.78.1520607555747; Fri, 09 Mar 2018 06:59:15 -0800 (PST) MIME-Version: 1.0 Sender: carpeddiem@gmail.com Received: by 10.107.163.13 with HTTP; Fri, 9 Mar 2018 06:58:55 -0800 (PST) In-Reply-To: <20180309120131.GA38546@zxy.spb.ru> References: <20180309120131.GA38546@zxy.spb.ru> From: Ed Maste Date: Fri, 9 Mar 2018 09:58:55 -0500 X-Google-Sender-Auth: kItTfUukVYpQYXxbBcSdVz8TZzU Message-ID: Subject: Re: Performance Benchmark for PTI (aka Meltdown mitigation) To: Slawa Olhovchenkov Cc: Arshan Khanifar , FreeBSD Current Content-Type: text/plain; charset="UTF-8" X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.25 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 09 Mar 2018 14:59:17 -0000 On 9 March 2018 at 07:01, Slawa Olhovchenkov wrote: > On Thu, Mar 08, 2018 at 05:04:11PM -0500, Arshan Khanifar wrote: > >> Executive Summary: >> - The PTI feature increases the system call times by more than 100%. >> - As a macrobenchmark, buildworld was used. Wall clock and user time >> showed no statistically-significant changes, while system time >> increased by less than 5%. >> >> This email contains the results for benchmarking the performance of the >> PTI patch on FreeBSD 12-current. As a microbenchmark, timing of >> getppid(2) system call was used, and as a macrobenchmark, a number of >> buildworld tasks were timed. >> > > Can you also run pre-patched kernel? It's not easy to do an apples-to-apples comparison as there were a few followup changes to the PTI work, interspersed with unrelated changes. That said, I think Arshan has some benchmarks obtained during the development of the PTI changes that may be illustrative. The best approach is probably to compare stable/11 at r329450 (last stable/11 revision before the merge) with r329462 with PTI and IBRS disabled.