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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 89B63C43334 for ; Fri, 8 Jul 2022 20:27:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239378AbiGHU1S (ORCPT ); Fri, 8 Jul 2022 16:27:18 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50618 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238702AbiGHU1S (ORCPT ); Fri, 8 Jul 2022 16:27:18 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7155F72EC6 for ; Fri, 8 Jul 2022 13:27:17 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 23030B80BFA for ; Fri, 8 Jul 2022 20:27:16 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id C2CBAC341C0; Fri, 8 Jul 2022 20:27:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1657312034; bh=+H3yTCfdgvpeNVak+h3TK80uml2j6JO6k5hKENucpA0=; h=Date:To:From:Subject:From; b=TexHJRex6FHze2QliLW/n5Gh/u0J4kf+xT4v9X2MttiPINEDEaQw8eT4d7d9453qi wUgguZQ4OiDTyBbPcxA1LuHHOaWDRoVdhuD8gvvSH3mQi7kUsQDfpkBb4YrRlU3uuf AeVy0s3gzQioo0QAl9VS05MWUhMXfEWDsY/ZY8GE= Date: Fri, 08 Jul 2022 13:27:14 -0700 To: mm-commits@vger.kernel.org, songmuchun@bytedance.com, shy828301@gmail.com, osalvador@suse.de, mike.kravetz@oracle.com, lkp@intel.com, liushixin2@huawei.com, linmiaohe@huawei.com, david@redhat.com, naoya.horiguchi@nec.com, akpm@linux-foundation.org From: Andrew Morton Subject: + mm-hugetlb-check-gigantic_page_runtime_supported-in-return_unused_surplus_pages.patch added to mm-unstable branch Message-Id: <20220708202714.C2CBAC341C0@smtp.kernel.org> Precedence: bulk Reply-To: linux-kernel@vger.kernel.org List-ID: X-Mailing-List: mm-commits@vger.kernel.org The patch titled Subject: mm/hugetlb: check gigantic_page_runtime_supported() in return_unused_surplus_pages() has been added to the -mm mm-unstable branch. Its filename is mm-hugetlb-check-gigantic_page_runtime_supported-in-return_unused_surplus_pages.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-hugetlb-check-gigantic_page_runtime_supported-in-return_unused_surplus_pages.patch This patch will later appear in the mm-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via the mm-everything branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there every 2-3 working days ------------------------------------------------------ From: Naoya Horiguchi Subject: mm/hugetlb: check gigantic_page_runtime_supported() in return_unused_surplus_pages() Date: Fri, 8 Jul 2022 14:36:46 +0900 Patch series "mm, hwpoison: enable 1GB hugepage support", v5. This patch (of 8): I found a weird state of 1GB hugepage pool, caused by the following procedure: - run a process reserving all free 1GB hugepages, - shrink free 1GB hugepage pool to zero (i.e. writing 0 to /sys/kernel/mm/hugepages/hugepages-1048576kB/nr_hugepages), then - kill the reserving process. , then all the hugepages are free *and* surplus at the same time. $ cat /sys/kernel/mm/hugepages/hugepages-1048576kB/nr_hugepages 3 $ cat /sys/kernel/mm/hugepages/hugepages-1048576kB/free_hugepages 3 $ cat /sys/kernel/mm/hugepages/hugepages-1048576kB/resv_hugepages 0 $ cat /sys/kernel/mm/hugepages/hugepages-1048576kB/surplus_hugepages 3 This state is resolved by reserving and allocating the pages then freeing them again, so this seems not to result in serious problem. But it's a little surprising (shrinking pool suddenly fails). This behavior is caused by hstate_is_gigantic() check in return_unused_surplus_pages(). This was introduced so long ago in 2008 by commit aa888a74977a ("hugetlb: support larger than MAX_ORDER"), and at that time the gigantic pages were not supposed to be allocated/freed at run-time. Now kernel can support runtime allocation/free, so let's check gigantic_page_runtime_supported() together. Link: https://lkml.kernel.org/r/20220708053653.964464-1-naoya.horiguchi@linux.dev Link: https://lkml.kernel.org/r/20220708053653.964464-2-naoya.horiguchi@linux.dev Signed-off-by: Naoya Horiguchi Cc: David Hildenbrand Cc: Mike Kravetz Cc: Miaohe Lin Cc: Liu Shixin Cc: Yang Shi Cc: Oscar Salvador Cc: Muchun Song Cc: kernel test robot Signed-off-by: Andrew Morton --- mm/hugetlb.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) --- a/mm/hugetlb.c~mm-hugetlb-check-gigantic_page_runtime_supported-in-return_unused_surplus_pages +++ a/mm/hugetlb.c @@ -2432,8 +2432,7 @@ static void return_unused_surplus_pages( /* 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_runtime_supported()) goto out; /* _ Patches currently in -mm which might be from naoya.horiguchi@nec.com are mm-hugetlb-separate-path-for-hwpoison-entry-in-copy_hugetlb_page_range.patch mm-hugetlb-check-gigantic_page_runtime_supported-in-return_unused_surplus_pages.patch mm-hugetlb-make-pud_huge-and-follow_huge_pud-aware-of-non-present-pud-entry.patch mm-hwpoison-hugetlb-support-saving-mechanism-of-raw-error-pages.patch mm-hwpoison-make-unpoison-aware-of-raw-error-info-in-hwpoisoned-hugepage.patch mm-hwpoison-set-pg_hwpoison-for-busy-hugetlb-pages.patch mm-hwpoison-make-__page_handle_poison-returns-int.patch mm-hwpoison-skip-raw-hwpoison-page-in-freeing-1gb-hugepage.patch mm-hwpoison-enable-memory-error-handling-on-1gb-hugepage.patch