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Thu, 12 Aug 2021 10:28:15 -0700 (PDT) Received: from turing-police ([2601:5c0:c380:d61::359]) by smtp.gmail.com with ESMTPSA id 37sm1478039qtf.33.2021.08.12.10.28.14 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 12 Aug 2021 10:28:14 -0700 (PDT) From: "Valdis Kl=?utf-8?Q?=c4=93?=tnieks" X-Google-Original-From: "Valdis Kl=?utf-8?Q?=c4=93?=tnieks" X-Mailer: exmh version 2.10.0-pre 07/05/2021 with nmh-1.7+dev To: SeongJae Park Cc: SeongJae Park , Andrew Morton , linux-mm@kvack.org, linux-kernel@vger.kernel.org In-Reply-To: <20210812094240.4492-1-sjpark@amazon.de> References: <20210812094240.4492-1-sjpark@amazon.de> Mime-Version: 1.0 Content-Type: multipart/signed; boundary="==_Exmh_1628789293_131750P"; micalg=pgp-sha256; protocol="application/pgp-signature" Content-Transfer-Encoding: 7bit Date: Thu, 12 Aug 2021 13:28:13 -0400 Message-ID: <167751.1628789293@turing-police> Authentication-Results: imf05.hostedemail.com; dkim=pass header.d=vt-edu.20150623.gappssmtp.com header.s=20150623 header.b=URsWBW9y; spf=pass (imf05.hostedemail.com: domain of valdis@vt.edu designates 209.85.160.177 as permitted sender) smtp.mailfrom=valdis@vt.edu; dmarc=pass (policy=none) header.from=vt.edu X-Rspamd-Server: rspam06 X-Rspamd-Queue-Id: 1D7415045074 X-Stat-Signature: pqa53zauqry4wtkupyqmqehzwd7saqyo X-HE-Tag: 1628789295-770258 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: --==_Exmh_1628789293_131750P Content-Type: text/plain; charset=us-ascii On Thu, 12 Aug 2021 09:42:40 -0000, SeongJae Park said: > - This feature adds PG_idle and PG_young flags in 'struct page'. PTE > - Accessed bit writers can set the state of the bit in the flags to let > - other PTE Accessed bit readers don't disturbed. > + This feature adds 'PG_idle' and 'PG_young' flags in 'struct page'. > + PTE Accessed bit writers can save the state of the bit in the flags > + to let other PTE Accessed bit readers don't get disturbed. Well, better English would be "to let other ... not be disturbed'. But I was rather hoping for an explanation of what "don't get disturbed" actually means. If you are "save the state of the bit", are you saving the *previous* value (in which case, other readers of the bit may or may not encounter changed behavior), or are you saving a shadow copy that may have different values than the original flags, and only used by a few routines? Or are you creating two new status flags that are only used by several optimized/fastpath routines and ignored by the other readers of the various flag bits? So a better description would be something like This feature adds two new status bits PG_idle and PG_young to 'struct page'. This allows passing additional information to certain users of PTE Accessed so they can use an optimized codepath bypassing expensive checks for certain common cases. or "so they can provide " or whatever this option is doing. --==_Exmh_1628789293_131750P Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Comment: Exmh version 2.9.0 11/07/2018 iQEcBAEBCAAGBQJhFVosAAoJEI0DS38y7CIcUrMH+QGFFKac8B0RfegkCazdDLtN p7d9cijWcXq1d4Tye/w8Sb+lUJwKOZcnz4mk5sUHwjVku9ZTJLB25T8ufpOjh/Em 4ZwuLP1CJzuMnZL2PMTbLIkqZiAKXrH/vXNv/RTiYX0Fg33e38cKxBnyWtcZHiPh 5b8BocR8VkmqD9aNsMCH7M8HMgqZMXBG9ohsMAi8NyZC2EWUEXWr899HmbAAfZH5 LoKG/wqCN8PnDLH0XFTdHjIyVPH03TOfqXU1YaIWoBla7TGcBitP9/PflQ57xWHc bYYrxoU6khL2vRXvKwWXWiti3Ug4NlpTfpy7mqt/JtomqkrHCsPVIXVgRKlSe7g= =EoUy -----END PGP SIGNATURE----- --==_Exmh_1628789293_131750P--