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 51934C433FE for ; Fri, 14 Jan 2022 22:08:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230222AbiANWIH (ORCPT ); Fri, 14 Jan 2022 17:08:07 -0500 Received: from ams.source.kernel.org ([145.40.68.75]:59978 "EHLO ams.source.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230220AbiANWIH (ORCPT ); Fri, 14 Jan 2022 17:08:07 -0500 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 9D586B8262E for ; Fri, 14 Jan 2022 22:08:06 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1CD19C36AE9; Fri, 14 Jan 2022 22:08:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1642198085; bh=X3CbClOOdYI8cFhZFL8AwWbzbDVa+nqZyRksH6v0Jkw=; h=Date:From:To:Subject:In-Reply-To:From; b=2I0V5DqqQkr5eIfwmeYSMQeWl+y8o/OtNJjCmb2sdT559cCGp9eoLJaR5mxBQtc4Z h+iCEgJ3ZJUGJKoyaQOo5QgbbHSfO+o8BVmUlvQuokBjHTKNy6AZIPPNKP+4adIMqp Jc+QLSd/wNPkI87iiqVL2htVEtJ0NQtzCWVH1aGk= Date: Fri, 14 Jan 2022 14:08:04 -0800 From: Andrew Morton To: aarcange@redhat.com, akpm@linux-foundation.org, almasrymina@google.com, axelrasmussen@google.com, linux-mm@kvack.org, mike.kravetz@oracle.com, mm-commits@vger.kernel.org, peterx@redhat.com, shuah@kernel.org, torvalds@linux-foundation.org Subject: [patch 093/146] userfaultfd/selftests: clean up hugetlb allocation code Message-ID: <20220114220804.dCcvxHVal%akpm@linux-foundation.org> In-Reply-To: <20220114140222.6b14f0061194d3200000c52d@linux-foundation.org> User-Agent: s-nail v14.8.16 Precedence: bulk Reply-To: linux-kernel@vger.kernel.org List-ID: X-Mailing-List: mm-commits@vger.kernel.org From: Mike Kravetz Subject: userfaultfd/selftests: clean up hugetlb allocation code The message for commit f5c73297181c ("userfaultfd/selftests: fix hugetlb area allocations") says there is no need to create a hugetlb file in the non-shared testing case. However, the commit did not actually change the code to prevent creation of the file. While it is technically true that there is no need to create and use a hugetlb file in the case of non-shared-testing, it is useful. This is because 'hole punching' of a hugetlb file has the potentially incorrect side effect of also removing pages from private mappings. The userfaultfd test relies on this side effect for removing pages from the destination buffer during rounds of stress testing. Remove the incomplete code that was added to deal with no hugetlb file. Just keep the code that prevents reserves from being created for the destination area. Link: https://lkml.kernel.org/r/20220104021729.111006-1-mike.kravetz@oracle.com Signed-off-by: Mike Kravetz Reviewed-by: Axel Rasmussen Cc: Peter Xu Cc: Andrea Arcangeli Cc: Mina Almasry Cc: Shuah Khan Signed-off-by: Andrew Morton --- tools/testing/selftests/vm/userfaultfd.c | 15 ++++++--------- 1 file changed, 6 insertions(+), 9 deletions(-) --- a/tools/testing/selftests/vm/userfaultfd.c~userfaultfd-selftests-clean-up-hugetlb-allocation-code +++ a/tools/testing/selftests/vm/userfaultfd.c @@ -87,7 +87,7 @@ static bool test_uffdio_minor = false; static bool map_shared; static int shm_fd; -static int huge_fd = -1; /* only used for hugetlb_shared test */ +static int huge_fd; static char *huge_fd_off0; static unsigned long long *count_verify; static int uffd = -1; @@ -223,9 +223,6 @@ static void noop_alias_mapping(__u64 *st static void hugetlb_release_pages(char *rel_area) { - if (huge_fd == -1) - return; - if (fallocate(huge_fd, FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE, rel_area == huge_fd_off0 ? 0 : nr_pages * page_size, nr_pages * page_size)) @@ -238,17 +235,17 @@ static void hugetlb_allocate_area(void * char **alloc_area_alias; *alloc_area = mmap(NULL, nr_pages * page_size, PROT_READ | PROT_WRITE, - map_shared ? MAP_SHARED : - MAP_PRIVATE | MAP_HUGETLB | + (map_shared ? MAP_SHARED : MAP_PRIVATE) | + MAP_HUGETLB | (*alloc_area == area_src ? 0 : MAP_NORESERVE), - huge_fd, - *alloc_area == area_src ? 0 : nr_pages * page_size); + huge_fd, *alloc_area == area_src ? 0 : + nr_pages * page_size); if (*alloc_area == MAP_FAILED) err("mmap of hugetlbfs file failed"); if (map_shared) { area_alias = mmap(NULL, nr_pages * page_size, PROT_READ | PROT_WRITE, - MAP_SHARED, + MAP_SHARED | MAP_HUGETLB, huge_fd, *alloc_area == area_src ? 0 : nr_pages * page_size); if (area_alias == MAP_FAILED) _