From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-0.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9B2A6C31E44 for ; Wed, 12 Jun 2019 00:55:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 72FE321721 for ; Wed, 12 Jun 2019 00:55:53 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="NiAwzvuW" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2406388AbfFLAzx (ORCPT ); Tue, 11 Jun 2019 20:55:53 -0400 Received: from mail-pf1-f195.google.com ([209.85.210.195]:43276 "EHLO mail-pf1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2406117AbfFLAzx (ORCPT ); Tue, 11 Jun 2019 20:55:53 -0400 Received: by mail-pf1-f195.google.com with SMTP id i189so8515090pfg.10; Tue, 11 Jun 2019 17:55:52 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:subject:to:cc:references:in-reply-to:mime-version :user-agent:message-id:content-transfer-encoding; bh=JNCR25wKoUF8GmXR1+h5Qxc2sputayqDi9OAgx3GkdA=; b=NiAwzvuW1158vo7YqCqImrGi+gOspOS5ptLbXAIoG+Z9ze7uMdcN2eGWAsbNMH7+TG 3ZkAe/orroen/eLz2qm7eGvkJnmLfn0Ao/sWgWXpra1h3e97Fbq8GTUU6tsqNa0XX05a hylXtqpcRAnnO0Mj6KHPmtmbR1ePDFiDX84pGRfqnwJNRN6N/PrW6Cr39MB8mYO7MJlz 5R3W6R2v9YZy+6iSs2yC/ugh7qMnOvJh1iKbpPuLSnT/ouMOHYhMPkWq+xopLIjw9uu9 yeTUr5c2xq1OasjqxvVRtr5VrtPFnBVEv4hsmatE9KIsBtR0qj+CcdswIM50TMbSCQvN o6Dw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:subject:to:cc:references:in-reply-to :mime-version:user-agent:message-id:content-transfer-encoding; bh=JNCR25wKoUF8GmXR1+h5Qxc2sputayqDi9OAgx3GkdA=; b=R5HR+XjXj44+vHeimHoFKSAZgrjD2qTGGD+MQgsUPI4z7uXaCcWDYG3h+GayoOpzuG nVaw5jp4rawhj5qcHlGwskh0y59Ema2P2UHD7Qh+FQs8lVS4SJ76ZawDq/bbHlKOIJYE jEKaKbFYoYC8dWo+F6uNDkb3pTHWZYbZOogeedxhji7S5vMLYIegdanZlVrCvC2F9iAj klPEufI0RO+ch8AEvfaDZBQh7tEc/PwrAFEUg5/9RKKbP1kU6K0uF1xSNIw/iupjO5Ic H9f50qdaOvraM4bpQCXeQlzz9IOlwaxQE2P/KGfNsGI4NOjj6yl3EWPd4pdUpAq6EZAn cHFQ== X-Gm-Message-State: APjAAAXHgo2fBKJZ/cJIY1QCDao4cP0bspsylNKZIwL5kEOJ8jueygfx K/Kv4B/+WzgfPLrvS+5gr2U= X-Google-Smtp-Source: APXvYqwFJLADjuhoiaHTsjm93GY2KEIrK+4logzMa1qKh7V/rBYbqMu9MhPfYO/mkPAOmVvGgW7CCQ== X-Received: by 2002:a63:b07:: with SMTP id 7mr22723250pgl.21.1560300952204; Tue, 11 Jun 2019 17:55:52 -0700 (PDT) Received: from localhost (242.60.168.202.static.comindico.com.au. [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 Sender: linux-mips-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-mips@vger.kernel.org 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 =