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=-3.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS autolearn=no 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 9CF41C11F65 for ; Wed, 30 Jun 2021 11:23:13 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 4357261628 for ; Wed, 30 Jun 2021 11:23:13 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4357261628 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id B42A88D01A0; Wed, 30 Jun 2021 07:23:12 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id B19B18D017A; Wed, 30 Jun 2021 07:23:12 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 9BBAA8D01A0; Wed, 30 Jun 2021 07:23:12 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0104.hostedemail.com [216.40.44.104]) by kanga.kvack.org (Postfix) with ESMTP id 757E28D017A for ; Wed, 30 Jun 2021 07:23:12 -0400 (EDT) Received: from smtpin27.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id 551E118024AFD for ; Wed, 30 Jun 2021 11:23:12 +0000 (UTC) X-FDA: 78310153824.27.3C6990D Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) by imf08.hostedemail.com (Postfix) with ESMTP id C6CCB30000A8 for ; Wed, 30 Jun 2021 11:23:10 +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=Qrj5IivtqnPita8/luPfOpstNFxH4Y1PmGJb28I+4HM=; b=KHSWYVNSEXqE+hAvHoVc7fT9bk hEybG4f2y4gDErI3lZGWGyRNBBc53Ku52AfOJoulx9w4gTCsMkQ+3bGHXBE2JOEatBYRHS3IJr9JL 6+rTND0YLsSmh03mf3yZ0oQ+jh82oH2VQHuleOnYsautd7SvnBZwI2bP6mH9y6MuVXC4FQiktIiuu XyD1Y1MBxT47ouppzTDbwLRgwl+l9R/q/R5oPklGzbUk/i0pR76NXykDMtOLW+uZhVwAMrPCqt/+4 OdfWsZURDjCZb5RqwPjqVb6kyHbKAcDsZw4XTXxktL+cvrOJslMxGkz0ofUkqerejMB25uOv+Gcw6 OEq9VJTg==; Received: from willy by casper.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1lyYIq-005GfN-NM; Wed, 30 Jun 2021 11:22:56 +0000 Date: Wed, 30 Jun 2021 12:22:48 +0100 From: Matthew Wilcox To: Michal Hocko Cc: linux-mm@kvack.org, cgroups@vger.kernel.org, Johannes Weiner , Vladimir Davydov Subject: Re: [PATCH v3 14/18] mm/memcg: Convert mem_cgroup_move_account() to use a folio Message-ID: References: <20210630040034.1155892-1-willy@infradead.org> <20210630040034.1155892-15-willy@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Authentication-Results: imf08.hostedemail.com; dkim=pass header.d=infradead.org header.s=casper.20170209 header.b=KHSWYVNS; spf=none (imf08.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-Rspamd-Server: rspam03 X-Rspamd-Queue-Id: C6CCB30000A8 X-Stat-Signature: 7t9crhh7uh5biid6k3jag8usgke3ghxp X-HE-Tag: 1625052190-7373 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 Wed, Jun 30, 2021 at 10:30:38AM +0200, Michal Hocko wrote: > > - if (PageAnon(page)) { > > - if (page_mapped(page)) { > > + if (folio_anon(folio)) { > > + if (folio_mapped(folio)) { > > __mod_lruvec_state(from_vec, NR_ANON_MAPPED, -nr_pages); > > __mod_lruvec_state(to_vec, NR_ANON_MAPPED, nr_pages); > > - if (PageTransHuge(page)) { > > + if (folio_multi(folio)) { > > Shouldn't be folio_transhuge? The resulting code is the same but > folio_transhuge is more explicit and matches the THP aspect. I genuinely don't know. For the benefit of those reading along, the important part of the context is: if (folio_mapped(folio)) { __mod_lruvec_state(from_vec, NR_ANON_MAPPED, -nr_pages); __mod_lruvec_state(to_vec, NR_ANON_MAPPED, nr_pages); if (folio_multi(folio)) { __mod_lruvec_state(from_vec, NR_ANON_THPS, -nr_pages); __mod_lruvec_state(to_vec, NR_ANON_THPS, nr_pages); } } We need to decide what 'NR_ANON_THPS' means in a folio-based world where we have folios of all orders. Does it count only the number of pages in folios >= HPAGE_PMD_SIZE? Or does it count the number of pages in folios > PAGE_SIZE? Similar question (and I suspect the same answer) for NR_SHMEM_THPS and NR_FILE_THPS. Right now, I've been accounting any multi-page folio as a THP, but I don't have a good sense of what the answer should be.