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 66EECC02192 for ; Wed, 5 Feb 2025 05:34:14 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id CC4C7280007; Wed, 5 Feb 2025 00:34:13 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id C7589280004; Wed, 5 Feb 2025 00:34:13 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id AED7D280007; Wed, 5 Feb 2025 00:34:13 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0010.hostedemail.com [216.40.44.10]) by kanga.kvack.org (Postfix) with ESMTP id 8D4F4280004 for ; Wed, 5 Feb 2025 00:34:13 -0500 (EST) Received: from smtpin19.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay10.hostedemail.com (Postfix) with ESMTP id 0095EC06F4 for ; Wed, 5 Feb 2025 05:34:12 +0000 (UTC) X-FDA: 83084775186.19.8CD399E Received: from invmail4.hynix.com (exvmail4.hynix.com [166.125.252.92]) by imf10.hostedemail.com (Postfix) with ESMTP id 5A32BC0006 for ; Wed, 5 Feb 2025 05:34:10 +0000 (UTC) Authentication-Results: imf10.hostedemail.com; dkim=none; dmarc=none; spf=pass (imf10.hostedemail.com: domain of honggyu.kim@sk.com designates 166.125.252.92 as permitted sender) smtp.mailfrom=honggyu.kim@sk.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1738733651; 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:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=xZOHp7XAQlbUJWp37NcoSnNn4zw6tkukQD7E9H9TE3Q=; b=l+bFL58WQJBGZrBKAQTTmiKKuL3K3MVMoGG26DsXmYMQg32GnQ3YWi2KMc53IBycmP8ffn jrdUiV7Sq4RgJTuH51YZ7pwFjLGsssetRQeX3u+k4XdYspptrTFTYu/lHyp4uzgA8WbgRr 1dJDVSGFh/TnD6bUyqjMOrXeJlkIjvA= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1738733651; a=rsa-sha256; cv=none; b=acLAtTT1wxwOLE3aSpbWg4SECPRBoiefUobjEkVh90SV17iI4kSMJoUywWEnZTmb7QFZ20 yWfXndGgyxORw+kgGelwQ8CWe3EzAt9yVBA9eJKZPxCbe4ws5j0D4B+voorEkB79BRW+ul YeBZaKqtmB7iG5e38WG77tIK0N9whwo= ARC-Authentication-Results: i=1; imf10.hostedemail.com; dkim=none; dmarc=none; spf=pass (imf10.hostedemail.com: domain of honggyu.kim@sk.com designates 166.125.252.92 as permitted sender) smtp.mailfrom=honggyu.kim@sk.com X-AuditID: a67dfc5b-3e1ff7000001d7ae-46-67a2f84f118f Message-ID: <92fb15d4-b8fe-4b73-ba2c-2ded3c9bd4ca@sk.com> Date: Wed, 5 Feb 2025 14:34:07 +0900 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Cc: kernel_team@skhynix.com, Joshua Hahn , gourry@gourry.net, hyeonggon.yoo@sk.com, rafael@kernel.org, lenb@kernel.org, gregkh@linuxfoundation.org, akpm@linux-foundation.org, rakie.kim@sk.com, dan.j.williams@intel.com, Jonathan.Cameron@huawei.com, dave.jiang@intel.com, horen.chuang@linux.dev, hannes@cmpxchg.org, linux-kernel@vger.kernel.org, linux-acpi@vger.kernel.org, linux-mm@kvack.org, kernel-team@meta.com Subject: Re: [PATCH v3] Weighted interleave auto-tuning Content-Language: ko To: "Huang, Ying" References: <20250115185854.1991771-1-joshua.hahnjy@gmail.com> <87ikq8h0w4.fsf@DESKTOP-5N7EMDA> <147aba6e-7e23-4ad1-9bd2-1ceac0f3d55b@sk.com> <87a5bjiqtk.fsf@DESKTOP-5N7EMDA> From: Honggyu Kim In-Reply-To: <87a5bjiqtk.fsf@DESKTOP-5N7EMDA> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFjrMIsWRmVeSWpSXmKPExsXC9ZZnoa7/j0XpBsv3GFjMWb+GzWL61AuM FiduNrJZ/Lx7nN2iefF6NovVm3wtbvefY7VYtfAam8XxrfPYLfZdBKrd+fAtm8Xyff2MFpd3 zWGzuLfmP6vF3C9TmS1Wr8lwEPA4/OY9s8fOWXfZPbrbLrN7tBx5y+qxeM9LJo9NqzrZPDZ9 msTucWLGbxaPnQ8tPRY2TGX22D93DbvHuYsVHp83yQXwRnHZpKTmZJalFunbJXBltK+Zz17Q JVOxdfUq5gbGo2JdjJwcEgImEtc2HmKEsXdsmssEYvMKWEq83XmRBcRmEVCRWDblOVRcUOLk zCdgcVEBeYn7t2awdzFycTAL7GeWuHZ/PVhCWMBcYuKMrawgNrOAiMTszjZmEFtEwEDi75XJ LCANQgJbGCVW7DrJBpJgE1CTuPJyEtgGTgFdiXMzt7BANJtJdG3tYoSw5SW2v53DDNIsIXCK XeLj7itMEGdLShxccYNlAqPgLCQXzkKyfBaSWbOQzFrAyLKKUSgzryw3MTPHRC+jMi+zQi85 P3cTIzBql9X+id7B+OlC8CFGAQ5GJR5eB8ZF6UKsiWXFlbmHGCU4mJVEeE9vX5AuxJuSWFmV WpQfX1Sak1p8iFGag0VJnNfoW3mKkEB6YklqdmpqQWoRTJaJg1OqgXFdzj634zYtJzgdJ3o9 XXF38dX+TRMDLI569N957P84sP3em8NBsrv6kmZc7G1tnNK4zM4xf3VJtlbxuVfnz4XYm/5N mjTPLb5g6szM8/EW4aeUM+9f+HVZSMLlyImF7mdbJGImMwR1bnHZ+cAqLF1rltCxsv64lSI/ Nl5oMl+28fXa0+8OhUUosRRnJBpqMRcVJwIAxdgo+dYCAAA= X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFtrOIsWRmVeSWpSXmKPExsXCNUNLT9f/x6J0g+/X5SzmrF/DZjF96gVG ixM3G9ksft49zm7RvHg9m8XqTb4Wt/vPsVrMXJtksWrhNTaL41vnsVvsuwhUf3juSVaLnQ/f slks39fPaHF51xw2i3tr/rNazP0yldni0LXnrBar12Q4CHscfvOe2WPnrLvsHt1tl9k9Wo68 ZfVYvOclk8emVZ1sHps+TWL3ODHjN4vHzoeWHgsbpjJ77J+7ht3j3MUKj2+3PTwWv/jA5PF5 k1wAfxSXTUpqTmZZapG+XQJXRvua+ewFXTIVW1evYm5gPCrWxcjJISFgIrFj01wmEJtXwFLi 7c6LLCA2i4CKxLIpz6HighInZz4Bi4sKyEvcvzWDvYuRi4NZYD+zxLX768ESwgLmEhNnbGUF sZkFRCRmd7Yxg9giAgYSf69MZgFpEBLYwiixYtdJNpAEm4CaxJWXk8A2cAroSpybuYUFotlM omtrFyOELS+x/e0c5gmMfLOQHDILyY5ZSFpmIWlZwMiyilEkM68sNzEzx1SvODujMi+zQi85 P3cTIzA6l9X+mbiD8ctl90OMAhyMSjy8DoyL0oVYE8uKK3MPMUpwMCuJ8J7eviBdiDclsbIq tSg/vqg0J7X4EKM0B4uSOK9XeGqCkEB6YklqdmpqQWoRTJaJg1OqgZH19GbRRIsrLFw+LKff 792v3Su+TO/6pttftqtYu6dHxE5tzlBamrI567DU5ttpNkxMXnMvdPspbFO6XBP8yPk75yLx NYL/G7+XivwrdL0p9CyzrsAiMpStyCLvfJjnsdobL8ptPkhO6Z2vdPIY++tzF1c+nrXvikXM tX1/djDMcny8sIctr1eJpTgj0VCLuag4EQCBVzE/ygIAAA== X-CFilter-Loop: Reflected X-Rspamd-Queue-Id: 5A32BC0006 X-Stat-Signature: 8kk3bxf4akzhjdi1kd65a8mraqwnpw55 X-Rspam-User: X-Rspamd-Server: rspam12 X-HE-Tag: 1738733650-863826 X-HE-Meta: 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 RuMeosIE 69Ydi3i+QQNxsFFUjJXYOnvP4CSIiiFf2zerAGREDppMPmb4SF4SXMDkOEe9a5/tFAYFoIJ1/R4xMChLSr2EpRj1rhmk3F/KbOS1rc82jzrldEvtAs081azJIZ5VYhBOPb7mxr0yMwR3gzB1YkLc3vQU/1A== 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: List-Subscribe: List-Unsubscribe: Hi Ying, On 1/22/2025 10:24 AM, Huang, Ying wrote: [snip] >>>> diff --git a/Documentation/ABI/testing/sysfs-kernel-mm-mempolicy-weighted-interleave b/Documentation/ABI/testing/sysfs-kernel-mm-mempolicy-weighted-interleave >>>> index 0b7972de04e9..d30dc29c53ff 100644 >>>> --- a/Documentation/ABI/testing/sysfs-kernel-mm-mempolicy-weighted-interleave >>>> +++ b/Documentation/ABI/testing/sysfs-kernel-mm-mempolicy-weighted-interleave >>>> @@ -20,6 +20,30 @@ Description: Weight configuration interface for nodeN >>>> Minimum weight: 1 >>>> Maximum weight: 255 >>>> - Writing an empty string or `0` will reset the weight >>>> to the >>>> - system default. The system default may be set by the kernel >>>> - or drivers at boot or during hotplug events. >>>> + Writing invalid values (i.e. any values not in [1,255], >>>> + empty string, ...) will return -EINVAL. >>>> + >>>> +What: /sys/kernel/mm/mempolicy/weighted_interleave/mode >>>> +Date: January 2025 >>>> +Contact: Linux memory management mailing list >>>> +Description: Auto-weighting configuration interface >>>> + >>>> + Configuration modes for weighted interleave. Can take one of >>>> + two options: "manual" and "auto". Default is "auto". >>>> + >>>> + In auto mode, all node weights are re-calculated and overwritten >>>> + (visible via the nodeN interfaces) whenever new bandwidth data >>>> + is made available either during boot or hotplug events. >>>> + >>>> + In manual mode, node weights can only be updated by the user. >>>> + If a node is hotplugged while the user is in manual mode, >>>> + the node will have a default weight of 1. >>>> + >>>> + Modes can be changed by writing either "auto" or "manual" to the >>>> + interface. All other strings will be ignored, and -EINVAL will >>>> + be returned. If "auto" is written to the interface but the >>>> + recalculation / updates fail at any point (-ENOMEM or -ENODEV) >>>> + then the mode will remain in manual mode. >>>> + >>>> + Writing a new weight to a node directly via the nodeN interface >>>> + will also automatically update the system to manual mode. >>> IMHO, this interface is somewhat hard to be used. Users need to >>> know >>> which value is legal. So, this will become something like, >>> $ cat mode >>> auto [manual] >>> $ echo auto > mode >>> $ cat mode >>> [auto] manual >> >> This is exactly I internally proposed to Hyeonggon, but couldn't share >> the idea directly here. >> >>> Unless it's possible we will add more modes in the future, this is >>> kind >>> of overkill for me. How about something simpler as below? >>> $ cat auto >>> true >>> $ echo 0 > auto >>> $ cat auto >>> false >> >> That also makes sense, but I feel like somewhat vague what "auto" false >> means. The "auto" might be better to be "use_hmat" instead and this >> makes "use_hmat" false more meaningful. "use_hmat_weight" or >> "use_hmat_info" might be another candidates. > > As Gregory pointed out in another email. hmat isn't good because it's > platform dependent. We may use something else to get default weights on > another platform. Sorry for the late reply. I prefered "mode" contains auto/manual and "hmat" names were my second thought, which may not be proper here as you mentioned. > > I'm open to other platform independent naming. For example, use_default. I'm also fine to your another proposal "auto" with Y/N, which is used in v4. > > [snip] > > --- > Best Regards, > Huang, Ying Thanks, Honggyu