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=-13.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=unavailable 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 B09C8C433E6 for ; Thu, 28 Jan 2021 21:43:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 75B7264DED for ; Thu, 28 Jan 2021 21:43:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231545AbhA1Vno (ORCPT ); Thu, 28 Jan 2021 16:43:44 -0500 Received: from mx2.suse.de ([195.135.220.15]:60692 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231403AbhA1VnK (ORCPT ); Thu, 28 Jan 2021 16:43:10 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id D4CFAAC55; Thu, 28 Jan 2021 21:42:21 +0000 (UTC) Date: Thu, 28 Jan 2021 22:42:19 +0100 From: Oscar Salvador To: David Hildenbrand Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, Andrew Morton , Thomas Gleixner , "Peter Zijlstra (Intel)" , Mike Rapoport , Michal Hocko , Wei Yang , linux-api@vger.kernel.org Subject: Re: [PATCH v2] mm/page_alloc: count CMA pages per zone and print them in /proc/zoneinfo Message-ID: <20210128214219.GA3113@localhost.localdomain> References: <20210127101813.6370-3-david@redhat.com> <20210128164533.18566-1-david@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210128164533.18566-1-david@redhat.com> Precedence: bulk List-ID: X-Mailing-List: linux-api@vger.kernel.org On Thu, Jan 28, 2021 at 05:45:33PM +0100, David Hildenbrand wrote: > Let's count the number of CMA pages per zone and print them in > /proc/zoneinfo. > > Having access to the total number of CMA pages per zone is helpful for > debugging purposes to know where exactly the CMA pages ended up, and to > figure out how many pages of a zone might behave differently, even after > some of these pages might already have been allocated. > > As one example, CMA pages part of a kernel zone cannot be used for > ordinary kernel allocations but instead behave more like ZONE_MOVABLE. > > For now, we are only able to get the global nr+free cma pages from > /proc/meminfo and the free cma pages per zone from /proc/zoneinfo. > > Example after this patch when booting a 6 GiB QEMU VM with > "hugetlb_cma=2G": > # cat /proc/zoneinfo | grep cma > cma 0 > nr_free_cma 0 > cma 0 > nr_free_cma 0 > cma 524288 > nr_free_cma 493016 > cma 0 > cma 0 > # cat /proc/meminfo | grep Cma > CmaTotal: 2097152 kB > CmaFree: 1972064 kB > > Note: We track/print only with CONFIG_CMA; "nr_free_cma" in /proc/zoneinfo > is currently also printed without CONFIG_CMA. > > Cc: Andrew Morton > Cc: Thomas Gleixner > Cc: "Peter Zijlstra (Intel)" > Cc: Mike Rapoport > Cc: Oscar Salvador > Cc: Michal Hocko > Cc: Wei Yang > Cc: linux-api@vger.kernel.org > Signed-off-by: David Hildenbrand IMHO looks better to me, thanks: Reviewed-by: Oscar Salvador > --- > > v1 -> v2: > - Print/track only with CONFIG_CMA > - Extend patch description > > --- > include/linux/mmzone.h | 6 ++++++ > mm/page_alloc.c | 1 + > mm/vmstat.c | 5 +++++ > 3 files changed, 12 insertions(+) > > diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h > index ae588b2f87ef..27d22fb22e05 100644 > --- a/include/linux/mmzone.h > +++ b/include/linux/mmzone.h > @@ -503,6 +503,9 @@ struct zone { > * bootmem allocator): > * managed_pages = present_pages - reserved_pages; > * > + * cma pages is present pages that are assigned for CMA use > + * (MIGRATE_CMA). > + * > * So present_pages may be used by memory hotplug or memory power > * management logic to figure out unmanaged pages by checking > * (present_pages - managed_pages). And managed_pages should be used > @@ -527,6 +530,9 @@ struct zone { > atomic_long_t managed_pages; > unsigned long spanned_pages; > unsigned long present_pages; > +#ifdef CONFIG_CMA > + unsigned long cma_pages; > +#endif > > const char *name; > > diff --git a/mm/page_alloc.c b/mm/page_alloc.c > index b031a5ae0bd5..9a82375bbcb2 100644 > --- a/mm/page_alloc.c > +++ b/mm/page_alloc.c > @@ -2168,6 +2168,7 @@ void __init init_cma_reserved_pageblock(struct page *page) > } > > adjust_managed_page_count(page, pageblock_nr_pages); > + page_zone(page)->cma_pages += pageblock_nr_pages; > } > #endif > > diff --git a/mm/vmstat.c b/mm/vmstat.c > index 7758486097f9..957680db41fa 100644 > --- a/mm/vmstat.c > +++ b/mm/vmstat.c > @@ -1650,6 +1650,11 @@ static void zoneinfo_show_print(struct seq_file *m, pg_data_t *pgdat, > zone->spanned_pages, > zone->present_pages, > zone_managed_pages(zone)); > +#ifdef CONFIG_CMA > + seq_printf(m, > + "\n cma %lu", > + zone->cma_pages); > +#endif > > seq_printf(m, > "\n protection: (%ld", > -- > 2.29.2 > -- Oscar Salvador SUSE L3