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 8AAEDC433EF for ; Wed, 13 Jul 2022 18:02:34 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id DFA16940157; Wed, 13 Jul 2022 14:02:33 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id DA9B6940134; Wed, 13 Jul 2022 14:02:33 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id C7180940157; Wed, 13 Jul 2022 14:02:33 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0013.hostedemail.com [216.40.44.13]) by kanga.kvack.org (Postfix) with ESMTP id B7C11940134 for ; Wed, 13 Jul 2022 14:02:33 -0400 (EDT) Received: from smtpin20.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay01.hostedemail.com (Postfix) with ESMTP id 6F12D60B3B for ; Wed, 13 Jul 2022 18:02:33 +0000 (UTC) X-FDA: 79682846586.20.88ECB5F Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by imf21.hostedemail.com (Postfix) with ESMTP id 0B85E1C00BB for ; Wed, 13 Jul 2022 18:02:29 +0000 (UTC) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id E66BEB81DE3; Wed, 13 Jul 2022 18:02:27 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1E36AC341C0; Wed, 13 Jul 2022 18:02:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1657735346; bh=dFwsBR8xE5FOMPaUe5ThWiyp2fWvoIbz6oSfJS72Cvw=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=UvL8asvQXigHtIpmedLOUWJvEx7u9NboDWnBaDEIZ/k8fK+HJXxFUZQdXd/tKcbte P7K3bOCegxEaBW0/iPTVYOEn953m6jnJiraguPpIIi1DzAAVUq6dK2SMPnqSo4yF3z Sm71CeBREfSo8hhpkwUeTfyje0s+YRTlHovfuCT4= Date: Wed, 13 Jul 2022 11:02:23 -0700 From: Andrew Morton To: "Zach O'Keefe" Cc: Yang Shi , Alex Shi , David Hildenbrand , David Rientjes , Matthew Wilcox , Michal Hocko , Pasha Tatashin , Peter Xu , Rongwei Wang , SeongJae Park , Song Liu , Vlastimil Babka , Zi Yan , Linux MM , Andrea Arcangeli , Arnd Bergmann , Axel Rasmussen , Chris Kennelly , Chris Zankel , Helge Deller , Hugh Dickins , Ivan Kokshaysky , "James E.J. Bottomley" , Jens Axboe , "Kirill A. Shutemov" , Matt Turner , Max Filippov , Miaohe Lin , Minchan Kim , Patrick Xia , Pavel Begunkov , Thomas Bogendoerfer , James Houghton Subject: Re: [mm-unstable v7 13/18] proc/smaps: add PMDMappable field to smaps Message-Id: <20220713110223.ead770e321900fbc4877d309@linux-foundation.org> In-Reply-To: References: <20220706235936.2197195-1-zokeefe@google.com> <20220706235936.2197195-14-zokeefe@google.com> X-Mailer: Sylpheed 3.7.0 (GTK+ 2.24.33; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit ARC-Authentication-Results: i=1; imf21.hostedemail.com; dkim=pass header.d=linux-foundation.org header.s=korg header.b=UvL8asvQ; dmarc=none; spf=pass (imf21.hostedemail.com: domain of akpm@linux-foundation.org designates 145.40.68.75 as permitted sender) smtp.mailfrom=akpm@linux-foundation.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1657735351; 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:dkim-signature; bh=IsfN5WysvOSGzxileZqZs6DeWJekmvq13vwJHNw2C2E=; b=GdcxVAGUYlNZeDw8+xyw95Qm4Kp6PSE5RWx3X1v5rWz3YVPxVfWRATFRQ/S8K/Ajb4qN64 cYPM9Ph7OUNHNbztXWKbl50hbaN2rOkGDvNZn2/oB+G1yL3aR99uCAgUe30i/bzuePoCiM MfvKt4dHrWymi2QncHr9G4wzFKAsn4M= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1657735351; a=rsa-sha256; cv=none; b=HZVc/rFCiUGbNhpZF8VccMd0D5rMz5du8MjN79FW8zBlwM3RFKifnPTKOQa/60bPkE5sHH mvVPM/knDDV6BBop1yuHZbZu/uo8gTzQlVc9qKitLwd/wqMJ92zUCS4lkb3tEpBU7kio2b /pQBreAG+TacjZHXqLAOKlhEwp+OnKM= X-Rspamd-Server: rspam04 X-Rspamd-Queue-Id: 0B85E1C00BB X-Stat-Signature: pjzwt7fxify96uqx6idtsexknfz14gsm Authentication-Results: imf21.hostedemail.com; dkim=pass header.d=linux-foundation.org header.s=korg header.b=UvL8asvQ; dmarc=none; spf=pass (imf21.hostedemail.com: domain of akpm@linux-foundation.org designates 145.40.68.75 as permitted sender) smtp.mailfrom=akpm@linux-foundation.org X-Rspam-User: X-HE-Tag: 1657735349-907185 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: On Tue, 12 Jul 2022 10:57:07 -0700 "Zach O'Keefe" wrote: > > I'm not sure what applications rely on this hint, but if they are just > > some test scripts, I think it should be fine. I don't think we > > guarantee the test scripts won't get broken. AFAIK some test scripts > > rely on the kernel dmesg text, for example, OOMs. And the meaning of > > the fields do change, for example, inactive anon of /proc/meminfo, > > which was changed by the patchset which put anon pages on inactive > > list first instead of active list. We already noticed the abnormal > > value from our monitoring tool when we adopted 5.10+ kernel. And > > /proc/vmstat also had some fields renamed, for example, > > workingset_refault of /proc/vmstat, it was split to > > workseting_refault_anon and workingset_refault_file, so we had to > > update our monitoring scripts accordingly. I think /proc/meminfo and > > /proc/vmstat are more heavily used than smaps. > > > > Thanks for the great context. My guess is, right now, THPelligible is more > useful as-is than if we were to relax it to MADV_COLLAPSE eligibility. As such, > I'm fine dropping this until a stronger and more immediate usecase presents > itself. Thanks for checking my rationale here. So... should I drop this patch?