From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pa0-f70.google.com (mail-pa0-f70.google.com [209.85.220.70]) by kanga.kvack.org (Postfix) with ESMTP id D34B96B02AA for ; Wed, 2 Nov 2016 22:52:26 -0400 (EDT) Received: by mail-pa0-f70.google.com with SMTP id gg9so16547590pac.6 for ; Wed, 02 Nov 2016 19:52:26 -0700 (PDT) Received: from EUR01-HE1-obe.outbound.protection.outlook.com (mail-he1eur01on0066.outbound.protection.outlook.com. [104.47.0.66]) by mx.google.com with ESMTPS id y67si6687085pfb.71.2016.11.02.19.52.25 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Wed, 02 Nov 2016 19:52:26 -0700 (PDT) From: Huang Shijie Subject: [PATCH 2/2] mm: hugetlb: support gigantic surplus pages Date: Thu, 3 Nov 2016 10:51:38 +0800 Message-ID: <1478141499-13825-3-git-send-email-shijie.huang@arm.com> In-Reply-To: <1478141499-13825-1-git-send-email-shijie.huang@arm.com> References: <1478141499-13825-1-git-send-email-shijie.huang@arm.com> MIME-Version: 1.0 Content-Type: text/plain Sender: owner-linux-mm@kvack.org List-ID: To: akpm@linux-foundation.org, catalin.marinas@arm.com Cc: n-horiguchi@ah.jp.nec.com, mhocko@suse.com, kirill.shutemov@linux.intel.com, aneesh.kumar@linux.vnet.ibm.com, gerald.schaefer@de.ibm.com, mike.kravetz@oracle.com, linux-mm@kvack.org, will.deacon@arm.com, steve.capper@arm.com, kaly.xin@arm.com, nd@arm.com, linux-arm-kernel@lists.infradead.org, Huang Shijie When testing the gigantic page whose order is too large for the buddy allocator, the libhugetlbfs test case "counter.sh" will fail. The failure is caused by: 1) kernel fails to allocate a gigantic page for the surplus case. And the gather_surplus_pages() will return NULL in the end. 2) The condition checks for "over-commit" is wrong. This patch adds code to allocate the gigantic page in the __alloc_huge_page(). After this patch, gather_surplus_pages() can return a gigantic page for the surplus case. This patch also changes the condition checks for: return_unused_surplus_pages() nr_overcommit_hugepages_store() After this patch, the counter.sh can pass for the gigantic page. Acked-by: Steve Capper Signed-off-by: Huang Shijie --- mm/hugetlb.c | 15 ++++++++++----- 1 file changed, 10 insertions(+), 5 deletions(-) diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 0bf4444..2b67aff 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -1574,7 +1574,7 @@ static struct page *__alloc_huge_page(struct hstate *h, struct page *page; unsigned int r_nid; - if (hstate_is_gigantic(h)) + if (hstate_is_gigantic(h) && !gigantic_page_supported()) return NULL; /* @@ -1619,7 +1619,13 @@ static struct page *__alloc_huge_page(struct hstate *h, } spin_unlock(&hugetlb_lock); - page = __hugetlb_alloc_buddy_huge_page(h, vma, addr, nid); + if (hstate_is_gigantic(h)) { + page = alloc_gigantic_page(nid, huge_page_order(h)); + if (page) + prep_compound_gigantic_page(page, huge_page_order(h)); + } else { + page = __hugetlb_alloc_buddy_huge_page(h, vma, addr, nid); + } spin_lock(&hugetlb_lock); if (page) { @@ -1786,8 +1792,7 @@ static void return_unused_surplus_pages(struct hstate *h, /* Uncommit the reservation */ h->resv_huge_pages -= unused_resv_pages; - /* Cannot return gigantic pages currently */ - if (hstate_is_gigantic(h)) + if (hstate_is_gigantic(h) && !gigantic_page_supported()) return; nr_pages = min(unused_resv_pages, h->surplus_huge_pages); @@ -2439,7 +2444,7 @@ static ssize_t nr_overcommit_hugepages_store(struct kobject *kobj, unsigned long input; struct hstate *h = kobj_to_hstate(kobj, NULL); - if (hstate_is_gigantic(h)) + if (hstate_is_gigantic(h) && !gigantic_page_supported()) return -EINVAL; err = kstrtoul(buf, 10, &input); -- 2.1.4 -- 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