From mboxrd@z Thu Jan 1 00:00:00 1970 From: Michal Hocko Subject: Re: [PATCH v3 14/18] mm/memcg: Convert mem_cgroup_move_account() to use a folio Date: Wed, 30 Jun 2021 14:45:33 +0200 Message-ID: References: <20210630040034.1155892-1-willy@infradead.org> <20210630040034.1155892-15-willy@infradead.org> Mime-Version: 1.0 Return-path: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1625057134; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=95yU7azCR9vrMUUQnIiZZ2YMD6UkK2dFrLDtadQtmOU=; b=EOoyWKwYBEWeOZVNOd4TZb8SKU8Uz1SwSHS+ebntuPIXR0lqulrlkuIDtG/mscBaLPtlkV BFO4i7lcUXk9mkcrkXfKll1Rihe4cfpKKjgNfsFOjG4/Q7xuzJUtcHmS50+7ZNs56hEdJT TCzeB5OW/m/JCuLuS7z0Z8jsIxgEmug= Content-Disposition: inline In-Reply-To: List-ID: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Matthew Wilcox Cc: linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org, cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Johannes Weiner , Vladimir Davydov On Wed 30-06-21 13:31:17, Matthew Wilcox wrote: > On Wed, Jun 30, 2021 at 02:20:38PM +0200, Michal Hocko wrote: > > On Wed 30-06-21 12:22:48, Matthew Wilcox wrote: > > > 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? > > > > At this stage we only have PMD based, right? I believe it would be > > simpler to stick with that at the moment and change that to a more > > generic way along with other places which need updating. > > > > Wrt. counters they do count pages so in this case this shouldn't be a > > problem. But we do have counters for pmd mappings and that might need > > some care. > > Looking at how these are reported: > > show_val_kb(m, "AnonHugePages: ", > global_node_page_state(NR_ANON_THPS)); > show_val_kb(m, "ShmemHugePages: ", > global_node_page_state(NR_SHMEM_THPS)); > show_val_kb(m, "ShmemPmdMapped: ", > global_node_page_state(NR_SHMEM_PMDMAPPED)); > show_val_kb(m, "FileHugePages: ", > global_node_page_state(NR_FILE_THPS)); > show_val_kb(m, "FilePmdMapped: ", > global_node_page_state(NR_FILE_PMDMAPPED)); > > it specifically refers to 'HugePages', so I think we need to only > count folios with order >= PMD_ORDER. Why? The presented value is in kB. It gives us a cumulative number of transparent large pages. Sure breakdown to respective orders would be impossible in general but the same would be the case if order > PMD_ORDER. I am not really sure how useful that information is in practice but that is a different story. > I'll make that change to > folio_transhuge() and use folio_transhuge() here. Thanks! -- Michal Hocko SUSE Labs 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=-5.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,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 4974AC11F68 for ; Wed, 30 Jun 2021 12:45:37 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id E6B2C61407 for ; Wed, 30 Jun 2021 12:45:36 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E6B2C61407 Authentication-Results: mail.kernel.org; dmarc=fail (p=quarantine dis=none) header.from=suse.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 18A318D01A8; Wed, 30 Jun 2021 08:45:36 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 13ADC8D01A2; Wed, 30 Jun 2021 08:45:36 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id F1D808D01A8; Wed, 30 Jun 2021 08:45:35 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0169.hostedemail.com [216.40.44.169]) by kanga.kvack.org (Postfix) with ESMTP id C9EC48D01A2 for ; Wed, 30 Jun 2021 08:45:35 -0400 (EDT) Received: from smtpin07.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id A1AAE182BF4E0 for ; Wed, 30 Jun 2021 12:45:35 +0000 (UTC) X-FDA: 78310361430.07.ADE939B Received: from smtp-out1.suse.de (smtp-out1.suse.de [195.135.220.28]) by imf08.hostedemail.com (Postfix) with ESMTP id 3968630000A8 for ; Wed, 30 Jun 2021 12:45:35 +0000 (UTC) Received: from relay2.suse.de (relay2.suse.de [149.44.160.134]) by smtp-out1.suse.de (Postfix) with ESMTP id 2201C225A1; Wed, 30 Jun 2021 12:45:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1625057134; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=95yU7azCR9vrMUUQnIiZZ2YMD6UkK2dFrLDtadQtmOU=; b=EOoyWKwYBEWeOZVNOd4TZb8SKU8Uz1SwSHS+ebntuPIXR0lqulrlkuIDtG/mscBaLPtlkV BFO4i7lcUXk9mkcrkXfKll1Rihe4cfpKKjgNfsFOjG4/Q7xuzJUtcHmS50+7ZNs56hEdJT TCzeB5OW/m/JCuLuS7z0Z8jsIxgEmug= Received: from suse.cz (unknown [10.100.201.86]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by relay2.suse.de (Postfix) with ESMTPS id E93CBA3B8C; Wed, 30 Jun 2021 12:45:33 +0000 (UTC) Date: Wed, 30 Jun 2021 14:45:33 +0200 From: Michal Hocko To: Matthew Wilcox 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=suse.com header.s=susede1 header.b=EOoyWKwY; dmarc=pass (policy=quarantine) header.from=suse.com; spf=pass (imf08.hostedemail.com: domain of mhocko@suse.com designates 195.135.220.28 as permitted sender) smtp.mailfrom=mhocko@suse.com X-Stat-Signature: 943on98dd39en9c7pnd6awhr8mkx7rgh X-Rspamd-Server: rspam04 X-Rspamd-Queue-Id: 3968630000A8 X-HE-Tag: 1625057135-370307 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 30-06-21 13:31:17, Matthew Wilcox wrote: > On Wed, Jun 30, 2021 at 02:20:38PM +0200, Michal Hocko wrote: > > On Wed 30-06-21 12:22:48, Matthew Wilcox wrote: > > > 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? > > > > At this stage we only have PMD based, right? I believe it would be > > simpler to stick with that at the moment and change that to a more > > generic way along with other places which need updating. > > > > Wrt. counters they do count pages so in this case this shouldn't be a > > problem. But we do have counters for pmd mappings and that might need > > some care. > > Looking at how these are reported: > > show_val_kb(m, "AnonHugePages: ", > global_node_page_state(NR_ANON_THPS)); > show_val_kb(m, "ShmemHugePages: ", > global_node_page_state(NR_SHMEM_THPS)); > show_val_kb(m, "ShmemPmdMapped: ", > global_node_page_state(NR_SHMEM_PMDMAPPED)); > show_val_kb(m, "FileHugePages: ", > global_node_page_state(NR_FILE_THPS)); > show_val_kb(m, "FilePmdMapped: ", > global_node_page_state(NR_FILE_PMDMAPPED)); > > it specifically refers to 'HugePages', so I think we need to only > count folios with order >= PMD_ORDER. Why? The presented value is in kB. It gives us a cumulative number of transparent large pages. Sure breakdown to respective orders would be impossible in general but the same would be the case if order > PMD_ORDER. I am not really sure how useful that information is in practice but that is a different story. > I'll make that change to > folio_transhuge() and use folio_transhuge() here. Thanks! -- Michal Hocko SUSE Labs