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 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 30943C433F5 for ; Tue, 11 Oct 2022 18:20:24 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 4BF8A6B0071; Tue, 11 Oct 2022 14:20:23 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 46F166B0073; Tue, 11 Oct 2022 14:20:23 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 35E596B0074; Tue, 11 Oct 2022 14:20:23 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0015.hostedemail.com [216.40.44.15]) by kanga.kvack.org (Postfix) with ESMTP id 2448F6B0071 for ; Tue, 11 Oct 2022 14:20:23 -0400 (EDT) Received: from smtpin29.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay10.hostedemail.com (Postfix) with ESMTP id D2F9BC1157 for ; Tue, 11 Oct 2022 18:20:22 +0000 (UTC) X-FDA: 80009483484.29.94EC8CE Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) by imf15.hostedemail.com (Postfix) with ESMTP id D5172A0025 for ; Tue, 11 Oct 2022 18:20:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=qzecNvEAd/3Dg0SsYsChABTL2C2tH/O8AsUWj1hnFcI=; b=NGCMNMiw48kZ4qCz/icSwGiMeZ o3g+twL7gPxReL7q1QxXz+DDVdl8EiimeEEFPVqZxgkjRcc84P9OLdTY5gzSWI6h7E1/Dt7bz8dDD jzUfcOvYkXlf8rO1kgz969f9NAFsP7ouwLyfh/vnHVtcq0M5SPMbC6SCcwI0wmYlNaoz71s960RTZ ylJAXLo68YgiVG0uBMV+hSbrIZ29HkKdoA54QldSEI1mOTqrzGP536G2rycwu5vDrQshIkVjUdLSm kQsvHZGWm2xCS34Sm4nVOSyrA9Uh0evjlhfCpYobLKY8oUveyHYVkJF6DHVfbXnP7mOYvMy/DFCV2 DcguWYHQ==; Received: from willy by casper.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1oiJrP-005CRx-JF; Tue, 11 Oct 2022 18:20:11 +0000 Date: Tue, 11 Oct 2022 19:20:11 +0100 From: Matthew Wilcox To: Stefan Roesch Cc: kernel-team@fb.com, linux-block@vger.kernel.org, linux-mm@kvack.org, axboe@kernel.dk, clm@meta.com Subject: Re: [RFC PATCH v1 00/14] mm/block: add bdi sysfs knobs Message-ID: References: <20221011010044.851537-1-shr@devkernel.io> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20221011010044.851537-1-shr@devkernel.io> ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1665512421; a=rsa-sha256; cv=none; b=eVpXQW5avUx/c+Ha079XBhWpFvWe3LX7MbSlZF/jWCU3eiBH3xsLRU9x23xzleC54bcHI/ ehpKzVOisaAccItzSrk6g4lPG682sIQmGAnKSRLA7OQLakCFSysZgBIJMLM7fNPhiul32E pOm7FENHT7aS0bdRQRKwhlsUjeCi2r0= ARC-Authentication-Results: i=1; imf15.hostedemail.com; dkim=pass header.d=infradead.org header.s=casper.20170209 header.b=NGCMNMiw; spf=none (imf15.hostedemail.com: domain of willy@infradead.org has no SPF policy when checking 90.155.50.34) smtp.mailfrom=willy@infradead.org; dmarc=none ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1665512421; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=qzecNvEAd/3Dg0SsYsChABTL2C2tH/O8AsUWj1hnFcI=; b=df0fSyU5mzhmGooUV0qMX7hjlafMPiYXESkLOI22XVn5i3HIoqqYjCfQmcLkVKTqBjCP8c MBqGnv69jdsUByG/h4bAWnNC4XUH6SCUzwEaPNo49bnpKDWfkBhEhL/iIuj0u/AfHRCq+e qf7aSxhVOnpOFWacSNzq/dHdhRt5RCU= X-Stat-Signature: geunqtsrs6n9j957oxrbiibnxk44z6gy X-Rspamd-Queue-Id: D5172A0025 X-Rspam-User: X-Rspamd-Server: rspam08 Authentication-Results: imf15.hostedemail.com; dkim=pass header.d=infradead.org header.s=casper.20170209 header.b=NGCMNMiw; spf=none (imf15.hostedemail.com: domain of willy@infradead.org has no SPF policy when checking 90.155.50.34) smtp.mailfrom=willy@infradead.org; dmarc=none X-HE-Tag: 1665512420-788356 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000036, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Mon, Oct 10, 2022 at 06:00:30PM -0700, Stefan Roesch wrote: > 2) Part of 10000 internal calculation > The max_ratio is based on percentage. With the current machine sizes percentage > values can be very high (1% of a 256GB main memory is already 2.5GB). This change > uses part of 10000 instead of percentages for the internal calculations. Why 10,000? If you need better accuracy than 1/1000, the next step should normally be parts per million.