From patchwork Wed Oct 6 19:45:15 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mina Almasry X-Patchwork-Id: 12540461 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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C9429C433F5 for ; Wed, 6 Oct 2021 19:45:27 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 6CADF61163 for ; Wed, 6 Oct 2021 19:45:27 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 6CADF61163 Authentication-Results: mail.kernel.org; dmarc=fail (p=reject dis=none) header.from=google.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kvack.org Received: by kanga.kvack.org (Postfix) id 00436900003; Wed, 6 Oct 2021 15:45:27 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id EF463900002; Wed, 6 Oct 2021 15:45:26 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id DBC88900003; Wed, 6 Oct 2021 15:45:26 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0101.hostedemail.com [216.40.44.101]) by kanga.kvack.org (Postfix) with ESMTP id CC88D900002 for ; Wed, 6 Oct 2021 15:45:26 -0400 (EDT) Received: from smtpin36.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id 77E8B18317FFC for ; Wed, 6 Oct 2021 19:45:26 +0000 (UTC) X-FDA: 78667041852.36.894CEB3 Received: from mail-yb1-f202.google.com (mail-yb1-f202.google.com [209.85.219.202]) by imf07.hostedemail.com (Postfix) with ESMTP id 237711000F65 for ; Wed, 6 Oct 2021 19:45:26 +0000 (UTC) Received: by mail-yb1-f202.google.com with SMTP id d81-20020a251d54000000b005b55772ca97so4707147ybd.19 for ; Wed, 06 Oct 2021 12:45:25 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=date:in-reply-to:message-id:mime-version:references:subject:from:cc; bh=33T3kN8uQn16VjXFihSM9nFCVFBJPamljnDuGFM1188=; b=C9/Kkv69wl8raB5EBUBCHfAtbA3dpzaPE12aiTtMbZchQK4J7ou96mNIwGeu50JvS0 mWDyvRH8D7yozdrWELAbHjsliEOD1z7Y78qET2gK1EiVHd1NkYHaYHo3aFfDAedgtHcP LmRqFVVJQKmWTd8Ym7Z3v7Yx4kwWh+IwNcnZAO+F4qSyes7O7NZdpl0boVz39zSWQzi+ Re7S0OhURShyHEET93kbngqQsvk7tZY8MlMSRUCUeU0uepUCqKhyDzBWM8wsALDyy5MA ikXnYj1Th14E23MLLdIgjERciR8FEELYNnotZMiGmLYotUFekdQS0TtVUMNgm1voolGU aS+w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:cc; bh=33T3kN8uQn16VjXFihSM9nFCVFBJPamljnDuGFM1188=; b=X4gb/3A1l7c9u562Jt330z7DQKZyzchejRvu5vsUA945rw0Ed9MG8nBh2hZ4+ei7eq eOtEt4y34JJwQ5gvlMrK1PjJ8FT30T59p1Y5H/9ktjdEH2Gm89RytkflWeA9SZYAOR0h wnsv+qdfI1CbiK7onQmYvEU7Q6wX3WSehD6pJURU0bCDYGKoJjFFe197erfyd7KwdMEJ IAsvfKr7zLPIFu5m4LjXU12xSdHgilSrPlcgv/pljcpsAd/0oo7qdgpoCh+KxUUlm3dn ER5/WAqrbQM2PIUOC0srpUxCvYwpzuT1PUS+2c5zy04Cgx65DXWLBnLgKJykIBg95bOk kh7Q== X-Gm-Message-State: AOAM530b2+6HmSrr/vX7edxFY1ev4+CmkfIpU1D/69Is7h+Hywr9EyOo ikU2GB4lSkOl74mK5A71aGmivMY2mkmFiW4GsQ== X-Google-Smtp-Source: ABdhPJxf1UlzLYHoQIJKia2VLSl+12IyFPv8t6mGna5TN89kTm4/HmmLxqDNiwGvrVWORw0Vew7eEPTRYieHrOninQ== X-Received: from almasrymina.svl.corp.google.com ([2620:15c:2cd:202:75ea:cd41:1f31:c196]) (user=almasrymina job=sendgmr) by 2002:a25:b4d:: with SMTP id 74mr29783375ybl.443.1633549525403; Wed, 06 Oct 2021 12:45:25 -0700 (PDT) Date: Wed, 6 Oct 2021 12:45:15 -0700 In-Reply-To: <20211006194515.423539-1-almasrymina@google.com> Message-Id: <20211006194515.423539-2-almasrymina@google.com> Mime-Version: 1.0 References: <20211006194515.423539-1-almasrymina@google.com> X-Mailer: git-send-email 2.33.0.882.g93a45727a2-goog Subject: [PATCH v4 2/2] mm, hugepages: Add hugetlb vma mremap() test From: Mina Almasry Cc: Mina Almasry , Mike Kravetz , Andrew Morton , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Ken Chen , Chris Kennelly , Michal Hocko , Vlastimil Babka , Kirill Shutemov X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: 237711000F65 X-Stat-Signature: xk3y4uoeakwjxgh6ftedu94jq8t7oy89 Authentication-Results: imf07.hostedemail.com; dkim=pass header.d=google.com header.s=20210112 header.b="C9/Kkv69"; dmarc=pass (policy=reject) header.from=google.com; spf=pass (imf07.hostedemail.com: domain of 31fxdYQsKCFg0BC0IHOC8D06EE6B4.2ECB8DKN-CCAL02A.EH6@flex--almasrymina.bounces.google.com designates 209.85.219.202 as permitted sender) smtp.mailfrom=31fxdYQsKCFg0BC0IHOC8D06EE6B4.2ECB8DKN-CCAL02A.EH6@flex--almasrymina.bounces.google.com X-HE-Tag: 1633549526-53777 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: Signed-off-by: Mina Almasry Cc: Mike Kravetz Cc: Andrew Morton Cc: linux-mm@kvack.org Cc: linux-kernel@vger.kernel.org Cc: Ken Chen Cc: Chris Kennelly Cc: Michal Hocko Cc: Vlastimil Babka Cc: Kirill Shutemov --- Changes in v4: - Added comments to make test output clearer. - Modified test case slightly to test hugepage alignment of new_addr. --- tools/testing/selftests/vm/.gitignore | 1 + tools/testing/selftests/vm/Makefile | 1 + tools/testing/selftests/vm/hugepage-mremap.c | 168 +++++++++++++++++++ 3 files changed, 170 insertions(+) create mode 100644 tools/testing/selftests/vm/hugepage-mremap.c -- 2.33.0.882.g93a45727a2-goog diff --git a/tools/testing/selftests/vm/.gitignore b/tools/testing/selftests/vm/.gitignore index b02eac613fdda..2e7e86e852828 100644 --- a/tools/testing/selftests/vm/.gitignore +++ b/tools/testing/selftests/vm/.gitignore @@ -1,5 +1,6 @@ # SPDX-License-Identifier: GPL-2.0-only hugepage-mmap +hugepage-mremap hugepage-shm khugepaged map_hugetlb diff --git a/tools/testing/selftests/vm/Makefile b/tools/testing/selftests/vm/Makefile index d9605bd10f2de..1607322a112c9 100644 --- a/tools/testing/selftests/vm/Makefile +++ b/tools/testing/selftests/vm/Makefile @@ -29,6 +29,7 @@ TEST_GEN_FILES = compaction_test TEST_GEN_FILES += gup_test TEST_GEN_FILES += hmm-tests TEST_GEN_FILES += hugepage-mmap +TEST_GEN_FILES += hugepage-mremap TEST_GEN_FILES += hugepage-shm TEST_GEN_FILES += khugepaged TEST_GEN_FILES += madv_populate diff --git a/tools/testing/selftests/vm/hugepage-mremap.c b/tools/testing/selftests/vm/hugepage-mremap.c new file mode 100644 index 0000000000000..ba35b5b13c52c --- /dev/null +++ b/tools/testing/selftests/vm/hugepage-mremap.c @@ -0,0 +1,168 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * hugepage-mremap: + * + * Example of remapping huge page memory in a user application using the + * mremap system call. Before running this application, make sure that the + * administrator has mounted the hugetlbfs filesystem (on some directory + * like /mnt) using the command mount -t hugetlbfs nodev /mnt. In this + * example, the app is requesting memory of size 10MB that is backed by + * huge pages. + * + */ + +#define _GNU_SOURCE +#include +#include +#include +#include +#include +#include +#include /* Definition of O_* constants */ +#include /* Definition of SYS_* constants */ +#include +#include +#include + +#define LENGTH (1UL * 1024 * 1024 * 1024) + +#define PROTECTION (PROT_READ | PROT_WRITE | PROT_EXEC) +#define FLAGS (MAP_SHARED | MAP_ANONYMOUS) + +static void check_bytes(char *addr) +{ + printf("First hex is %x\n", *((unsigned int *)addr)); +} + +static void write_bytes(char *addr) +{ + unsigned long i; + + for (i = 0; i < LENGTH; i++) + *(addr + i) = (char)i; +} + +static int read_bytes(char *addr) +{ + unsigned long i; + + check_bytes(addr); + for (i = 0; i < LENGTH; i++) + if (*(addr + i) != (char)i) { + printf("Mismatch at %lu\n", i); + return 1; + } + return 0; +} + +static void register_region_with_uffd(char *addr, size_t len) +{ + long uffd; /* userfaultfd file descriptor */ + struct uffdio_api uffdio_api; + struct uffdio_register uffdio_register; + + /* Create and enable userfaultfd object. */ + + uffd = syscall(__NR_userfaultfd, O_CLOEXEC | O_NONBLOCK); + if (uffd == -1) { + perror("userfaultfd"); + exit(1); + } + + uffdio_api.api = UFFD_API; + uffdio_api.features = 0; + if (ioctl(uffd, UFFDIO_API, &uffdio_api) == -1) { + perror("ioctl-UFFDIO_API"); + exit(1); + } + + /* Create a private anonymous mapping. The memory will be + * demand-zero paged--that is, not yet allocated. When we + * actually touch the memory, it will be allocated via + * the userfaultfd. + */ + + addr = mmap(NULL, len, PROT_READ | PROT_WRITE, + MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); + if (addr == MAP_FAILED) { + perror("mmap"); + exit(1); + } + + printf("Address returned by mmap() = %p\n", addr); + + /* Register the memory range of the mapping we just created for + * handling by the userfaultfd object. In mode, we request to track + * missing pages (i.e., pages that have not yet been faulted in). + */ + + uffdio_register.range.start = (unsigned long)addr; + uffdio_register.range.len = len; + uffdio_register.mode = UFFDIO_REGISTER_MODE_MISSING; + if (ioctl(uffd, UFFDIO_REGISTER, &uffdio_register) == -1) { + perror("ioctl-UFFDIO_REGISTER"); + exit(1); + } +} + +int main(void) +{ + int ret = 0; + + int fd = open("/mnt/huge/test", O_CREAT | O_RDWR, 0755); + + if (fd < 0) { + perror("Open failed"); + exit(1); + } + + /* mmap to a PUD aligned address to hopefully trigger pmd sharing. */ + unsigned long suggested_addr = 0x7eaa40000000; + void *haddr = mmap((void *)suggested_addr, LENGTH, PROTECTION, + MAP_HUGETLB | MAP_SHARED | MAP_POPULATE, fd, 0); + printf("Map haddr: Returned address is %p\n", haddr); + if (haddr == MAP_FAILED) { + perror("mmap1"); + exit(1); + } + + /* mmap again to a dummy address to hopefully trigger pmd sharing. */ + suggested_addr = 0x7daa40000000; + void *daddr = mmap((void *)suggested_addr, LENGTH, PROTECTION, + MAP_HUGETLB | MAP_SHARED | MAP_POPULATE, fd, 0); + printf("Map daddr: Returned address is %p\n", daddr); + if (daddr == MAP_FAILED) { + perror("mmap3"); + exit(1); + } + + /* Note vaddr is not hugepage aligned. Mremap should hugepage align the + * vaddr on remap. + */ + suggested_addr = 0x7faa4002000; + void *vaddr = + mmap((void *)suggested_addr, LENGTH, PROTECTION, FLAGS, -1, 0); + printf("Map vaddr: Returned address is %p\n", vaddr); + if (vaddr == MAP_FAILED) { + perror("mmap2"); + exit(1); + } + + register_region_with_uffd(haddr, LENGTH); + + void *addr = mremap(haddr, LENGTH, LENGTH, + MREMAP_MAYMOVE | MREMAP_FIXED, vaddr); + if (addr == MAP_FAILED) { + perror("mremap"); + exit(1); + } + + printf("Mremap: Returned address is %p\n", addr); + check_bytes(addr); + write_bytes(addr); + ret = read_bytes(addr); + + munmap(addr, LENGTH); + + return ret; +}