From owner-freebsd-stable@freebsd.org Fri Dec 6 14:22:49 2019 Return-Path: Delivered-To: freebsd-stable@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id 7CF531CD131 for ; Fri, 6 Dec 2019 14:22:49 +0000 (UTC) (envelope-from kostikbel@gmail.com) Received: from kib.kiev.ua (kib.kiev.ua [IPv6:2001:470:d5e7:1::1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) server-signature RSA-PSS (4096 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 47Tvtw3dfzz4Sxp for ; Fri, 6 Dec 2019 14:22:48 +0000 (UTC) (envelope-from kostikbel@gmail.com) Received: from tom.home (kib@localhost [127.0.0.1]) by kib.kiev.ua (8.15.2/8.15.2) with ESMTPS id xB6EMMt7012299 (version=TLSv1.3 cipher=TLS_AES_256_GCM_SHA384 bits=256 verify=NO); Fri, 6 Dec 2019 16:22:25 +0200 (EET) (envelope-from kostikbel@gmail.com) DKIM-Filter: OpenDKIM Filter v2.10.3 kib.kiev.ua xB6EMMt7012299 Received: (from kostik@localhost) by tom.home (8.15.2/8.15.2/Submit) id xB6EMLsX012298; Fri, 6 Dec 2019 16:22:21 +0200 (EET) (envelope-from kostikbel@gmail.com) X-Authentication-Warning: tom.home: kostik set sender to kostikbel@gmail.com using -f Date: Fri, 6 Dec 2019 16:22:21 +0200 From: Konstantin Belousov To: "O'Connor, Daniel" Cc: freebsd-stable Subject: Re: Disabling speculative execution mitigations Message-ID: <20191206142221.GL2744@kib.kiev.ua> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.12.2 (2019-09-21) X-Spam-Status: No, score=-1.0 required=5.0 tests=ALL_TRUSTED,BAYES_00, DKIM_ADSP_CUSTOM_MED,FORGED_GMAIL_RCVD,FREEMAIL_FROM, NML_ADSP_CUSTOM_MED autolearn=no autolearn_force=no version=3.4.2 X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on tom.home X-Rspamd-Queue-Id: 47Tvtw3dfzz4Sxp X-Spamd-Bar: - Authentication-Results: mx1.freebsd.org; dkim=none; dmarc=fail reason="No valid SPF, No valid DKIM" header.from=gmail.com (policy=none); spf=softfail (mx1.freebsd.org: 2001:470:d5e7:1::1 is neither permitted nor denied by domain of kostikbel@gmail.com) smtp.mailfrom=kostikbel@gmail.com X-Spamd-Result: default: False [-2.00 / 15.00]; ARC_NA(0.00)[]; NEURAL_HAM_MEDIUM(-1.00)[-1.000,0]; DMARC_POLICY_SOFTFAIL(0.10)[gmail.com : No valid SPF, No valid DKIM,none]; FROM_HAS_DN(0.00)[]; FREEMAIL_FROM(0.00)[gmail.com]; NEURAL_HAM_LONG(-1.00)[-1.000,0]; MIME_GOOD(-0.10)[text/plain]; HAS_XAW(0.00)[]; R_SPF_SOFTFAIL(0.00)[~all:c]; IP_SCORE_FREEMAIL(0.00)[]; TO_MATCH_ENVRCPT_SOME(0.00)[]; TO_DN_ALL(0.00)[]; RCPT_COUNT_TWO(0.00)[2]; IP_SCORE(0.00)[ip: (-2.76), ipnet: 2001:470::/32(-4.65), asn: 6939(-3.53), country: US(-0.05)]; FROM_EQ_ENVFROM(0.00)[]; R_DKIM_NA(0.00)[]; FREEMAIL_ENVFROM(0.00)[gmail.com]; ASN(0.00)[asn:6939, ipnet:2001:470::/32, country:US]; MIME_TRACE(0.00)[0:+]; RCVD_TLS_ALL(0.00)[]; RCVD_COUNT_TWO(0.00)[2] X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 06 Dec 2019 14:22:49 -0000 On Fri, Dec 06, 2019 at 03:51:04PM +1030, O'Connor, Daniel wrote: > Hi, > I am trying to track down a performance drop with the ASPEED xorg video driver between FreeBSD 11 and 12 (I'm not expecting miracles from it but it was basically unusable..) > > I wondered if some of the speculative execution mitigations could be causing the problem so I did some digging and found these.. > > vm.pmap.pti="0" # Disable page table isolation > hw.ibrs_disable="1" # Disable Indirect Branch Restricted Speculation This line enables IBRS. > hw.mds_disable="0" # Disable Microarchitectural Data Sampling flush > hw.vmm.vmx="1" # Don't flush RSB on vmexit (presumably only affects bhyve etc) I have no idea what this line should configure. > hw.lazy_fpu_switch="1" # Lazily flush FPU > > Does anyone know of any others? Did you read security(7) (on HEAD)? > > I have 2 systems with the same motherboard (Supermicro X11SSH-F), one is older and runs FreeBSD 11 (and had an older BIOS_ and the newer runs FreeBSD 12. > > FWIW on FreeBSD 11 the performance (measured by a subset of x11perf benchmarks) went down 40% after updating to the latest BIOS (2.2a). Unfortunately on FreeBSD 12 rolling back to the original BIOS (2.2) did not improve performance. > > -- > Daniel O'Connor > "The nice thing about standards is that there > are so many of them to choose from." > -- Andrew Tanenbaum > > > _______________________________________________ > freebsd-stable@freebsd.org mailing list > https://lists.freebsd.org/mailman/listinfo/freebsd-stable > To unsubscribe, send any mail to "freebsd-stable-unsubscribe@freebsd.org"