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[202.168.60.242]) by smtp.gmail.com with ESMTPSA id u2sm3765259pjv.9.2019.06.11.17.55.50 (version=TLS1_3 cipher=AEAD-AES256-GCM-SHA384 bits=256/256); Tue, 11 Jun 2019 17:55:51 -0700 (PDT) Date: Wed, 12 Jun 2019 10:52:53 +1000 From: Nicholas Piggin Subject: Re: [PATCH 16/16] mm: pass get_user_pages_fast iterator arguments in a structure To: Rich Felker , "David S. Miller" , Christoph Hellwig , James Hogan , Paul Burton , Linus Torvalds , Yoshinori Sato Cc: Andrey Konovalov , Benjamin Herrenschmidt , Khalid Aziz , linux-kernel@vger.kernel.org, linux-mips@vger.kernel.org, linux-mm@kvack.org, linuxppc-dev@lists.ozlabs.org, linux-sh@vger.kernel.org, Michael Ellerman , Paul Mackerras , sparclinux@vger.kernel.org, x86@kernel.org References: <20190611144102.8848-1-hch@lst.de> <20190611144102.8848-17-hch@lst.de> In-Reply-To: <20190611144102.8848-17-hch@lst.de> MIME-Version: 1.0 User-Agent: astroid/0.14.0 (https://github.com/astroidmail/astroid) Message-Id: <1560300464.nijubslu3h.astroid@bobo.none> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable 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: Christoph Hellwig's on June 12, 2019 12:41 am: > Instead of passing a set of always repeated arguments down the > get_user_pages_fast iterators, create a struct gup_args to hold them and > pass that by reference. This leads to an over 100 byte .text size > reduction for x86-64. What does this do for performance? I've found this pattern can be bad for store aliasing detection. Thanks, Nick =