From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wr0-f197.google.com (mail-wr0-f197.google.com [209.85.128.197]) by kanga.kvack.org (Postfix) with ESMTP id AC0686B0253 for ; Mon, 20 Nov 2017 19:51:15 -0500 (EST) Received: by mail-wr0-f197.google.com with SMTP id t92so7035197wrc.13 for ; Mon, 20 Nov 2017 16:51:15 -0800 (PST) Received: from mail.linuxfoundation.org (mail.linuxfoundation.org. [140.211.169.12]) by mx.google.com with ESMTPS id s7si9201057wrg.141.2017.11.20.16.51.13 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 20 Nov 2017 16:51:14 -0800 (PST) Date: Mon, 20 Nov 2017 16:51:10 -0800 From: Andrew Morton Subject: Re: [PATCH v2] mm: show total hugetlb memory consumption in /proc/meminfo Message-Id: <20171120165110.587918bf75ffecb8144da66c@linux-foundation.org> In-Reply-To: <20171115231409.12131-1-guro@fb.com> References: <20171115231409.12131-1-guro@fb.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Roman Gushchin Cc: linux-mm@kvack.org, Michal Hocko , Johannes Weiner , Mike Kravetz , "Aneesh Kumar K.V" , Andrea Arcangeli , Dave Hansen , David Rientjes , kernel-team@fb.com, linux-kernel@vger.kernel.org On Wed, 15 Nov 2017 23:14:09 +0000 Roman Gushchin wrote: > Currently we display some hugepage statistics (total, free, etc) > in /proc/meminfo, but only for default hugepage size (e.g. 2Mb). > > If hugepages of different sizes are used (like 2Mb and 1Gb on x86-64), > /proc/meminfo output can be confusing, as non-default sized hugepages > are not reflected at all, and there are no signs that they are > existing and consuming system memory. > > To solve this problem, let's display the total amount of memory, > consumed by hugetlb pages of all sized (both free and used). > Let's call it "Hugetlb", and display size in kB to match generic > /proc/meminfo style. > > For example, (1024 2Mb pages and 2 1Gb pages are pre-allocated): > $ cat /proc/meminfo > MemTotal: 8168984 kB > MemFree: 3789276 kB > <...> > CmaFree: 0 kB > HugePages_Total: 1024 > HugePages_Free: 1024 > HugePages_Rsvd: 0 > HugePages_Surp: 0 > Hugepagesize: 2048 kB > Hugetlb: 4194304 kB > DirectMap4k: 32632 kB > DirectMap2M: 4161536 kB > DirectMap1G: 6291456 kB > > Also, this patch updates corresponding docs to reflect > Hugetlb entry meaning and difference between Hugetlb and > HugePages_Total * Hugepagesize. > > ... > > --- a/mm/hugetlb.c > +++ b/mm/hugetlb.c > @@ -2973,20 +2973,32 @@ int hugetlb_overcommit_handler(struct ctl_table *table, int write, > > void hugetlb_report_meminfo(struct seq_file *m) > { > - struct hstate *h = &default_hstate; > + struct hstate *h; > + unsigned long total = 0; > + > if (!hugepages_supported()) > return; > - seq_printf(m, > - "HugePages_Total: %5lu\n" > - "HugePages_Free: %5lu\n" > - "HugePages_Rsvd: %5lu\n" > - "HugePages_Surp: %5lu\n" > - "Hugepagesize: %8lu kB\n", > - h->nr_huge_pages, > - h->free_huge_pages, > - h->resv_huge_pages, > - h->surplus_huge_pages, > - 1UL << (huge_page_order(h) + PAGE_SHIFT - 10)); > + > + for_each_hstate(h) { > + unsigned long count = h->nr_huge_pages; > + > + total += (PAGE_SIZE << huge_page_order(h)) * count; > + > + if (h == &default_hstate) I'm not understanding this test. Are we assuming that default_hstate always refers to the highest-index hstate? If so why, and is that valid? > + seq_printf(m, > + "HugePages_Total: %5lu\n" > + "HugePages_Free: %5lu\n" > + "HugePages_Rsvd: %5lu\n" > + "HugePages_Surp: %5lu\n" > + "Hugepagesize: %8lu kB\n", > + count, > + h->free_huge_pages, > + h->resv_huge_pages, > + h->surplus_huge_pages, > + (PAGE_SIZE << huge_page_order(h)) / 1024); > + } > + > + seq_printf(m, "Hugetlb: %8lu kB\n", total / 1024); > } -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org