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[76.21.111.180]) by smtp.gmail.com with ESMTPSA id w11sm10388273pfn.4.2020.01.25.14.43.34 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Sat, 25 Jan 2020 14:43:35 -0800 (PST) From: Mark D Rustad Message-Id: <4E95BFAA-A115-4159-AA4F-6AAB548C6E6C@gmail.com> Content-Type: multipart/signed; boundary="Apple-Mail=_96A2D9E9-5BC9-4886-ACE9-60D07BD7E836"; protocol="application/pgp-signature"; micalg=pgp-sha256 Mime-Version: 1.0 (Mac OS X Mail 12.4 \(3445.104.11\)) Subject: Re: [PATCH v16] x86/split_lock: Enable split lock detection by kernel Date: Sat, 25 Jan 2020 14:43:33 -0800 In-Reply-To: <20200125220706.GA18290@agluck-desk2.amr.corp.intel.com> Cc: Thomas Gleixner , Arvind Sankar , "Christopherson, Sean J" , Peter Zijlstra , Ingo Molnar , "Yu, Fenghua" , Ingo Molnar , Borislav Petkov , H Peter Anvin , "Raj, Ashok" , "Shankar, Ravi V" , linux-kernel , x86 To: "Luck, Tony" References: <20200122185514.GA16010@agluck-desk2.amr.corp.intel.com> <20200122224245.GA2331824@rani.riverdale.lan> <3908561D78D1C84285E8C5FCA982C28F7F54887A@ORSMSX114.amr.corp.intel.com> <20200123004507.GA2403906@rani.riverdale.lan> <20200123035359.GA23659@agluck-desk2.amr.corp.intel.com> <20200123044514.GA2453000@rani.riverdale.lan> <20200123231652.GA4457@agluck-desk2.amr.corp.intel.com> <87h80kmta4.fsf@nanos.tec.linutronix.de> <20200125024727.GA32483@agluck-desk2.amr.corp.intel.com> <875zgzmz5e.fsf@nanos.tec.linutronix.de> <20200125220706.GA18290@agluck-desk2.amr.corp.intel.com> X-Mailer: Apple Mail (2.3445.104.11) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --Apple-Mail=_96A2D9E9-5BC9-4886-ACE9-60D07BD7E836 Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset=us-ascii; delsp=yes; format=flowed On Jan 25, 2020, at 2:07 PM, Luck, Tony wrote: > - Transitioning between modes at runtime isn't supported and disabling > is tracked per task, so hardware will always reach a steady state that > matches the configured mode. Maybe "isn't supported" is not really the right wording. I would think that if it truly weren't supported that you really shouldn't be changing the mode at all at runtime. Do you really just mean "isn't atomic"? Or is there something deeper about it? If so, are there other possible risks associated with changing the mode at runtime? Sorry, the wording just happened to catch my eye and my mind immediately went to "how can you be doing something that is not supported?" -- Mark Rustad, MRustad@gmail.com --Apple-Mail=_96A2D9E9-5BC9-4886-ACE9-60D07BD7E836 Content-Transfer-Encoding: 7bit Content-Disposition: attachment; filename=signature.asc Content-Type: application/pgp-signature; name=signature.asc Content-Description: Message signed with OpenPGP -----BEGIN PGP SIGNATURE----- Comment: GPGTools - http://gpgtools.org iQIzBAEBCAAdFiEE6ug8b0Wg+ULmnksNPA7/547j7m4FAl4sxJUACgkQPA7/547j 7m6fGg/8DRLCqJy1zWIUGJMYPBZgTgFxPj7tdyfGy88BC3es4lulPgvdkD9Mj11z 42jKFnQCZWUhpzIlpVv5hO28TZp/L+bkZbUa5iukwCaL7NTN6eiCvoxOd+nqzby9 GWU5XLmFUvgiS4LiGqub4K6I33898xjVh9+R2cXfHZxUmGnPzvQT8Hjg85PBhsra kWMKY9XLtu20vnBkwMpbj5PAhHDImF/aljoawgmnIo2xX1N2WNiWBOFNEWPqiP4M ZZxTgeMye+MmrhktQJDH0To+dBtB+Hyu+nr8YG81wOZ1EMna7murx7obSQdXDI4x DgPf3Q38JrJglTNe09I79+OjsQY+zLEG2oKkZ/NtKJ5x97AkVf4U3Cojuc8z27yW kNF60eroJP8FKr/S1BUY5bcQ/nevNP5aIZkdjI0drqBwx1IzVhII8IDZB3zcmXh5 1lcO/p1U93x6VtF9pldl/ykQDjCIk3d8+dbpR6IrkSphkwLyUWBhh+4ZVRMSIoWw bgWu7St106u5Ht/ECy8gsxIOXW0vycbqghgn8DMSB1HufnaAqNL+6Yjfr6l0Uk8c 5MM0q7dGYGpxvbdqS/dYfheb1kgEt9k7mT52Wi6Q8qI9ttNlNrT6xTAEElrMbT40 NbOHq4FcZDoF2gaPJzbt8MpzkH+y3yB2RopMkTFCs3E3Ck3dCIw= =uBBO -----END PGP SIGNATURE----- --Apple-Mail=_96A2D9E9-5BC9-4886-ACE9-60D07BD7E836--