From patchwork Tue Jul 28 10:04:50 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Ricardo_Ca=C3=B1uelo?= X-Patchwork-Id: 11688839 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id F1DC413B6 for ; Tue, 28 Jul 2020 10:09:09 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id BB88A207E8 for ; Tue, 28 Jul 2020 10:09:09 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org BB88A207E8 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=collabora.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id ED1C26B0024; Tue, 28 Jul 2020 06:09:08 -0400 (EDT) Delivered-To: linux-mm-outgoing@kvack.org Received: by kanga.kvack.org (Postfix, from userid 40) id E82AC8D0005; Tue, 28 Jul 2020 06:09:08 -0400 (EDT) X-Original-To: int-list-linux-mm@kvack.org X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id D70D36B0026; Tue, 28 Jul 2020 06:09:08 -0400 (EDT) X-Original-To: linux-mm@kvack.org X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0222.hostedemail.com [216.40.44.222]) by kanga.kvack.org (Postfix) with ESMTP id C13646B0024 for ; Tue, 28 Jul 2020 06:09:08 -0400 (EDT) Received: from smtpin09.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id 861551EF1 for ; Tue, 28 Jul 2020 10:09:08 +0000 (UTC) X-FDA: 77087061576.09.actor52_4f15ad926f69 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin09.hostedemail.com (Postfix) with ESMTP id 6070F180AD81A for ; Tue, 28 Jul 2020 10:09:08 +0000 (UTC) X-Spam-Summary: 1,0,0,889b800ef8ab3f53,d41d8cd98f00b204,ricardo.canuelo@collabora.com,,RULES_HIT:1:41:152:355:379:541:800:960:966:973:988:989:1260:1261:1277:1311:1313:1314:1345:1431:1437:1515:1516:1518:1593:1594:1605:1676:1730:1747:1777:1792:2196:2199:2393:2538:2559:2562:2637:2689:2693:2914:3138:3139:3140:3141:3142:3865:3866:3867:3868:3870:3871:3872:3874:4321:4384:4385:4395:4605:5007:6119:6261:6609:6690:7652:7875:7903:8603:8957:10004:10946:11026:11232:11473:11657:11658:11914:12043:12296:12297:12438:12517:12519:12555:12895:12986:13894:14394:14659:21080:21451:21627:21795:21990:30003:30034:30051:30054:30056:30067:30070,0,RBL:46.235.227.227:@collabora.com:.lbl8.mailshell.net-62.2.15.100 64.100.201.201;04y8p49i43tjfrcuamnsm8gj9yd89yc3pcy5bnx7iq81cyipep8ekibzcz6obyo.7ize7n44zpse4y4gg9j9m9yjbfur7zwa3zsp9zqmeqzzhhjydx1jopafruqwkkg.w-lbl8.mailshell.net-223.238.255.100,CacheIP:none,Bayesian:0.5,0.5,0.5,Netcheck:none,DomainCache:0,MSF:not bulk,SPF:fp,MSBL:0,DNSBL:neutral,Custom_rules:0: 0:0,LFti X-HE-Tag: actor52_4f15ad926f69 X-Filterd-Recvd-Size: 12105 Received: from bhuna.collabora.co.uk (bhuna.collabora.co.uk [46.235.227.227]) by imf14.hostedemail.com (Postfix) with ESMTP for ; Tue, 28 Jul 2020 10:09:07 +0000 (UTC) Received: from [127.0.0.1] (localhost [127.0.0.1]) (Authenticated sender: rcn) with ESMTPSA id 51753296389 From: =?utf-8?q?Ricardo_Ca=C3=B1uelo?= To: akpm@linux-foundation.org Cc: kernel@collabora.com, linux-kselftest@vger.kernel.org, linux-mm@kvack.org Subject: [PATCH] selftests: add mincore() tests Date: Tue, 28 Jul 2020 12:04:50 +0200 Message-Id: <20200728100450.4065-1-ricardo.canuelo@collabora.com> X-Mailer: git-send-email 2.18.0 MIME-Version: 1.0 X-Rspamd-Queue-Id: 6070F180AD81A X-Spamd-Result: default: False [0.00 / 100.00] X-Rspamd-Server: rspam03 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: Add a test suite for the mincore() syscall. It tests most of its use cases as well as its interface. Tests implemented: - basic interface test - behavior on anonymous mappings - behavior on anonymous mappings with huge tlb pages - file-backed mapping with a regular file - file-backed mapping with a tmpfs file Signed-off-by: Ricardo Cañuelo --- Tested in next-20200727 with: make -C tools/testing/selftests and make -C tools/testing/selftests run_tests tools/testing/selftests/Makefile | 1 + tools/testing/selftests/mincore/.gitignore | 2 + tools/testing/selftests/mincore/Makefile | 6 + .../selftests/mincore/mincore_selftest.c | 361 ++++++++++++++++++ 4 files changed, 370 insertions(+) create mode 100644 tools/testing/selftests/mincore/.gitignore create mode 100644 tools/testing/selftests/mincore/Makefile create mode 100644 tools/testing/selftests/mincore/mincore_selftest.c diff --git a/tools/testing/selftests/Makefile b/tools/testing/selftests/Makefile index e03bc15ce731..9018f45d631d 100644 --- a/tools/testing/selftests/Makefile +++ b/tools/testing/selftests/Makefile @@ -32,6 +32,7 @@ TARGETS += lkdtm TARGETS += membarrier TARGETS += memfd TARGETS += memory-hotplug +TARGETS += mincore TARGETS += mount TARGETS += mqueue TARGETS += net diff --git a/tools/testing/selftests/mincore/.gitignore b/tools/testing/selftests/mincore/.gitignore new file mode 100644 index 000000000000..15c4dfc2df00 --- /dev/null +++ b/tools/testing/selftests/mincore/.gitignore @@ -0,0 +1,2 @@ +# SPDX-License-Identifier: GPL-2.0+ +mincore_selftest diff --git a/tools/testing/selftests/mincore/Makefile b/tools/testing/selftests/mincore/Makefile new file mode 100644 index 000000000000..38c7db1e8926 --- /dev/null +++ b/tools/testing/selftests/mincore/Makefile @@ -0,0 +1,6 @@ +# SPDX-License-Identifier: GPL-2.0+ + +CFLAGS += -Wall + +TEST_GEN_PROGS := mincore_selftest +include ../lib.mk diff --git a/tools/testing/selftests/mincore/mincore_selftest.c b/tools/testing/selftests/mincore/mincore_selftest.c new file mode 100644 index 000000000000..5a1e85ff5d32 --- /dev/null +++ b/tools/testing/selftests/mincore/mincore_selftest.c @@ -0,0 +1,361 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * kselftest suite for mincore(). + * + * Copyright (C) 2020 Collabora, Ltd. + */ + +#define _GNU_SOURCE + +#include +#include +#include +#include +#include +#include +#include +#include + +#include "../kselftest.h" +#include "../kselftest_harness.h" + +/* Default test file size: 4MB */ +#define MB (1UL << 20) +#define FILE_SIZE (4 * MB) + + +/* + * Tests the user interface. This test triggers most of the documented + * error conditions in mincore(). + */ +TEST(basic_interface) +{ + int retval; + int page_size; + unsigned char vec[1]; + char *addr; + + page_size = sysconf(_SC_PAGESIZE); + + /* Query a 0 byte sized range */ + retval = mincore(0, 0, vec); + EXPECT_EQ(0, retval); + + /* Addresses in the specified range are invalid or unmapped */ + errno = 0; + retval = mincore(NULL, page_size, vec); + EXPECT_EQ(-1, retval); + EXPECT_EQ(ENOMEM, errno); + + errno = 0; + addr = mmap(NULL, page_size, PROT_READ | PROT_WRITE, + MAP_SHARED | MAP_ANONYMOUS, -1, 0); + ASSERT_NE(MAP_FAILED, addr) { + TH_LOG("mmap error: %s", strerror(errno)); + } + + /* argument is not page-aligned */ + errno = 0; + retval = mincore(addr + 1, page_size, vec); + EXPECT_EQ(-1, retval); + EXPECT_EQ(EINVAL, errno); + + /* argument is too large */ + errno = 0; + retval = mincore(addr, -1, vec); + EXPECT_EQ(-1, retval); + EXPECT_EQ(ENOMEM, errno); + + /* argument points to an illegal address */ + errno = 0; + retval = mincore(addr, page_size, NULL); + EXPECT_EQ(-1, retval); + EXPECT_EQ(EFAULT, errno); + munmap(addr, page_size); +} + + +/* + * Test mincore() behavior on a private anonymous page mapping. + * Check that the page is not loaded into memory right after the mapping + * but after accessing it (on-demand allocation). + * Then free the page and check that it's not memory-resident. + */ +TEST(check_anonymous_locked_pages) +{ + unsigned char vec[1]; + char *addr; + int retval; + int page_size; + + page_size = sysconf(_SC_PAGESIZE); + + /* Map one page and check it's not memory-resident */ + errno = 0; + addr = mmap(NULL, page_size, PROT_READ | PROT_WRITE, + MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); + ASSERT_NE(MAP_FAILED, addr) { + TH_LOG("mmap error: %s", strerror(errno)); + } + retval = mincore(addr, page_size, vec); + ASSERT_EQ(0, retval); + ASSERT_EQ(0, vec[0]) { + TH_LOG("Page found in memory before use"); + } + + /* Touch the page and check again. It should now be in memory */ + addr[0] = 1; + mlock(addr, page_size); + retval = mincore(addr, page_size, vec); + ASSERT_EQ(0, retval); + ASSERT_EQ(1, vec[0]) { + TH_LOG("Page not found in memory after use"); + } + + /* + * It shouldn't be memory-resident after unlocking it and + * marking it as unneeded. + */ + munlock(addr, page_size); + madvise(addr, page_size, MADV_DONTNEED); + retval = mincore(addr, page_size, vec); + ASSERT_EQ(0, retval); + ASSERT_EQ(0, vec[0]) { + TH_LOG("Page in memory after being zapped"); + } + munmap(addr, page_size); +} + + +/* + * Check mincore() behavior on huge pages. + * This test will be skipped if the mapping fails (ie. if there are no + * huge pages available). + * + * Make sure the system has at least one free huge page, check + * "HugePages_Free" in /proc/meminfo. + * Increment /sys/kernel/mm/hugepages/hugepages-2048kB/nr_hugepages if + * needed. + */ +TEST(check_huge_pages) +{ + unsigned char vec[1]; + char *addr; + int retval; + int page_size; + + page_size = sysconf(_SC_PAGESIZE); + + errno = 0; + addr = mmap(NULL, page_size, PROT_READ | PROT_WRITE, + MAP_PRIVATE | MAP_ANONYMOUS | MAP_HUGETLB, + -1, 0); + if (addr == MAP_FAILED) { + if (errno == ENOMEM) + SKIP(return, "No huge pages available."); + else + TH_LOG("mmap error: %s", strerror(errno)); + } + retval = mincore(addr, page_size, vec); + ASSERT_EQ(0, retval); + ASSERT_EQ(0, vec[0]) { + TH_LOG("Page found in memory before use"); + } + + addr[0] = 1; + mlock(addr, page_size); + retval = mincore(addr, page_size, vec); + ASSERT_EQ(0, retval); + ASSERT_EQ(1, vec[0]) { + TH_LOG("Page not found in memory after use"); + } + + munlock(addr, page_size); + munmap(addr, page_size); +} + + +/* + * Test mincore() behavior on a file-backed page. + * No pages should be loaded into memory right after the mapping. Then, + * accessing any address in the mapping range should load the page + * containing the address and a number of subsequent pages (readahead). + * + * The actual readahead settings depend on the test environment, so we + * can't make a lot of assumptions about that. This test covers the most + * general cases. + */ +TEST(check_file_mmap) +{ + unsigned char *vec; + int vec_size; + char *addr; + int retval; + int page_size; + int fd; + int i; + int ra_pages = 0; + + page_size = sysconf(_SC_PAGESIZE); + vec_size = FILE_SIZE / page_size; + if (FILE_SIZE % page_size) + vec_size++; + + vec = calloc(vec_size, sizeof(unsigned char)); + ASSERT_NE(NULL, vec) { + TH_LOG("Can't allocate array"); + } + + errno = 0; + fd = open(".", O_TMPFILE | O_RDWR, 0600); + ASSERT_NE(-1, fd) { + TH_LOG("Can't create temporary file: %s", + strerror(errno)); + } + errno = 0; + retval = fallocate(fd, 0, 0, FILE_SIZE); + ASSERT_EQ(0, retval) { + TH_LOG("Error allocating space for the temporary file: %s", + strerror(errno)); + } + + /* + * Map the whole file, the pages shouldn't be fetched yet. + */ + errno = 0; + addr = mmap(NULL, FILE_SIZE, PROT_READ | PROT_WRITE, + MAP_SHARED, fd, 0); + ASSERT_NE(MAP_FAILED, addr) { + TH_LOG("mmap error: %s", strerror(errno)); + } + retval = mincore(addr, FILE_SIZE, vec); + ASSERT_EQ(0, retval); + for (i = 0; i < vec_size; i++) { + ASSERT_EQ(0, vec[i]) { + TH_LOG("Unexpected page in memory"); + } + } + + /* + * Touch a page in the middle of the mapping. We expect the next + * few pages (the readahead window) to be populated too. + */ + addr[FILE_SIZE / 2] = 1; + retval = mincore(addr, FILE_SIZE, vec); + ASSERT_EQ(0, retval); + ASSERT_EQ(1, vec[FILE_SIZE / 2 / page_size]) { + TH_LOG("Page not found in memory after use"); + } + + i = FILE_SIZE / 2 / page_size + 1; + while (i < vec_size && vec[i]) { + ra_pages++; + i++; + } + EXPECT_GT(ra_pages, 0) { + TH_LOG("No read-ahead pages found in memory"); + } + + EXPECT_LT(i, vec_size) { + TH_LOG("Read-ahead pages reached the end of the file"); + } + /* + * End of the readahead window. The rest of the pages shouldn't + * be in memory. + */ + if (i < vec_size) { + while (i < vec_size && !vec[i]) + i++; + EXPECT_EQ(vec_size, i) { + TH_LOG("Unexpected page in memory beyond readahead window"); + } + } + + munmap(addr, FILE_SIZE); + close(fd); + free(vec); +} + + +/* + * Test mincore() behavior on a page backed by a tmpfs file. This test + * performs the same steps as the previous one. However, we don't expect + * any readahead in this case. + */ +TEST(check_tmpfs_mmap) +{ + unsigned char *vec; + int vec_size; + char *addr; + int retval; + int page_size; + int fd; + int i; + int ra_pages = 0; + + page_size = sysconf(_SC_PAGESIZE); + vec_size = FILE_SIZE / page_size; + if (FILE_SIZE % page_size) + vec_size++; + + vec = calloc(vec_size, sizeof(unsigned char)); + ASSERT_NE(NULL, vec) { + TH_LOG("Can't allocate array"); + } + + errno = 0; + fd = open("/dev/shm", O_TMPFILE | O_RDWR, 0600); + ASSERT_NE(-1, fd) { + TH_LOG("Can't create temporary file: %s", + strerror(errno)); + } + errno = 0; + retval = fallocate(fd, 0, 0, FILE_SIZE); + ASSERT_EQ(0, retval) { + TH_LOG("Error allocating space for the temporary file: %s", + strerror(errno)); + } + + /* + * Map the whole file, the pages shouldn't be fetched yet. + */ + errno = 0; + addr = mmap(NULL, FILE_SIZE, PROT_READ | PROT_WRITE, + MAP_SHARED, fd, 0); + ASSERT_NE(MAP_FAILED, addr) { + TH_LOG("mmap error: %s", strerror(errno)); + } + retval = mincore(addr, FILE_SIZE, vec); + ASSERT_EQ(0, retval); + for (i = 0; i < vec_size; i++) { + ASSERT_EQ(0, vec[i]) { + TH_LOG("Unexpected page in memory"); + } + } + + /* + * Touch a page in the middle of the mapping. We expect only + * that page to be fetched into memory. + */ + addr[FILE_SIZE / 2] = 1; + retval = mincore(addr, FILE_SIZE, vec); + ASSERT_EQ(0, retval); + ASSERT_EQ(1, vec[FILE_SIZE / 2 / page_size]) { + TH_LOG("Page not found in memory after use"); + } + + i = FILE_SIZE / 2 / page_size + 1; + while (i < vec_size && vec[i]) { + ra_pages++; + i++; + } + ASSERT_EQ(ra_pages, 0) { + TH_LOG("Read-ahead pages found in memory"); + } + + munmap(addr, FILE_SIZE); + close(fd); + free(vec); +} + +TEST_HARNESS_MAIN