From patchwork Thu Mar 17 10:33:21 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Muhammad Usama Anjum X-Patchwork-Id: 552397 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 8D226C433EF for ; Thu, 17 Mar 2022 10:34:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232605AbiCQKfQ (ORCPT ); Thu, 17 Mar 2022 06:35:16 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58056 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232597AbiCQKfQ (ORCPT ); Thu, 17 Mar 2022 06:35:16 -0400 Received: from bhuna.collabora.co.uk (bhuna.collabora.co.uk [IPv6:2a00:1098:0:82:1000:25:2eeb:e3e3]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 29BA1DE936; Thu, 17 Mar 2022 03:33:59 -0700 (PDT) Received: from [127.0.0.1] (localhost [127.0.0.1]) (Authenticated sender: usama.anjum) with ESMTPSA id 312121F44FD5 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=collabora.com; s=mail; t=1647513237; bh=vkOmIpb65jl2/KSIPy8hOvjOKFgiEmDAD06aY4dtfdA=; h=From:To:Cc:Subject:Date:From; b=N5fyGtOugo+DolCSWn541/erLx3k7/OCq/TltPSUuzwLOHD+6qVSl4B8Lrt5tlr41 lu6yMRrhoLmK4sxwAmkW6wt0SsR8x9wSd5jebSOPYPUwM21x7zxBAiVbvyOp88gveW 9MnjHhwhAveSgmwZ+1T/gUmGkAk9M4o/msWUNJAenk9yA0/c+SXRJkFTFnMD/q8NiK JjbSCJ9RkIYF4Ff3KEjRn1/Jdl9L2XoUDpWUDsJ6CLmm+qXjZ1pVp0nVASiy2qsnLY u+drxGKjdW41Im4sJnHiVBnBJVzRD26abGyqe7ZUAVXzKBukq7LYQuH/pWdM9lPJst 1R3E8SpWZVuhQ== From: Muhammad Usama Anjum To: Andrew Morton , Shuah Khan Cc: Muhammad Usama Anjum , kernel@collabora.com, krisman@collabora.com, david@redhat.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-kselftest@vger.kernel.org Subject: [PATCH V5 1/2] selftests: vm: bring common functions to a new file Date: Thu, 17 Mar 2022 15:33:21 +0500 Message-Id: <20220317103323.94799-1-usama.anjum@collabora.com> X-Mailer: git-send-email 2.30.2 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org Bring common functions to a new file while keeping code as much same as possible. These functions can be used in the new tests. This helps in avoiding code duplication. Signed-off-by: Muhammad Usama Anjum --- Changes in V5: Keep moved code as same as possible - Updated macros names - Removed macro used to show bit number of dirty bit, added a comment instead - Corrected indentation --- tools/testing/selftests/vm/Makefile | 7 +- tools/testing/selftests/vm/madv_populate.c | 34 +----- .../selftests/vm/split_huge_page_test.c | 79 +------------ tools/testing/selftests/vm/vm_util.c | 107 ++++++++++++++++++ tools/testing/selftests/vm/vm_util.h | 10 ++ 5 files changed, 124 insertions(+), 113 deletions(-) create mode 100644 tools/testing/selftests/vm/vm_util.c create mode 100644 tools/testing/selftests/vm/vm_util.h diff --git a/tools/testing/selftests/vm/Makefile b/tools/testing/selftests/vm/Makefile index 5e43f072f5b76..4e68edb26d6b6 100644 --- a/tools/testing/selftests/vm/Makefile +++ b/tools/testing/selftests/vm/Makefile @@ -34,7 +34,7 @@ TEST_GEN_FILES += hugepage-mremap TEST_GEN_FILES += hugepage-shm TEST_GEN_FILES += hugepage-vmemmap TEST_GEN_FILES += khugepaged -TEST_GEN_FILES += madv_populate +TEST_GEN_PROGS = madv_populate TEST_GEN_FILES += map_fixed_noreplace TEST_GEN_FILES += map_hugetlb TEST_GEN_FILES += map_populate @@ -47,7 +47,7 @@ TEST_GEN_FILES += on-fault-limit TEST_GEN_FILES += thuge-gen TEST_GEN_FILES += transhuge-stress TEST_GEN_FILES += userfaultfd -TEST_GEN_FILES += split_huge_page_test +TEST_GEN_PROGS += split_huge_page_test TEST_GEN_FILES += ksm_tests ifeq ($(MACHINE),x86_64) @@ -91,6 +91,9 @@ TEST_FILES := test_vmalloc.sh KSFT_KHDR_INSTALL := 1 include ../lib.mk +$(OUTPUT)/madv_populate: vm_util.c +$(OUTPUT)/split_huge_page_test: vm_util.c + ifeq ($(MACHINE),x86_64) BINARIES_32 := $(patsubst %,$(OUTPUT)/%,$(BINARIES_32)) BINARIES_64 := $(patsubst %,$(OUTPUT)/%,$(BINARIES_64)) diff --git a/tools/testing/selftests/vm/madv_populate.c b/tools/testing/selftests/vm/madv_populate.c index 3ee0e82756002..715a42e8e2cdb 100644 --- a/tools/testing/selftests/vm/madv_populate.c +++ b/tools/testing/selftests/vm/madv_populate.c @@ -18,6 +18,7 @@ #include #include "../kselftest.h" +#include "vm_util.h" /* * For now, we're using 2 MiB of private anonymous memory for all tests. @@ -26,18 +27,6 @@ static size_t pagesize; -static uint64_t pagemap_get_entry(int fd, char *start) -{ - const unsigned long pfn = (unsigned long)start / pagesize; - uint64_t entry; - int ret; - - ret = pread(fd, &entry, sizeof(entry), pfn * sizeof(entry)); - if (ret != sizeof(entry)) - ksft_exit_fail_msg("reading pagemap failed\n"); - return entry; -} - static bool pagemap_is_populated(int fd, char *start) { uint64_t entry = pagemap_get_entry(fd, start); @@ -46,13 +35,6 @@ static bool pagemap_is_populated(int fd, char *start) return entry & 0xc000000000000000ull; } -static bool pagemap_is_softdirty(int fd, char *start) -{ - uint64_t entry = pagemap_get_entry(fd, start); - - return entry & 0x0080000000000000ull; -} - static void sense_support(void) { char *addr; @@ -258,20 +240,6 @@ static bool range_is_not_softdirty(char *start, ssize_t size) return ret; } -static void clear_softdirty(void) -{ - int fd = open("/proc/self/clear_refs", O_WRONLY); - const char *ctrl = "4"; - int ret; - - if (fd < 0) - ksft_exit_fail_msg("opening clear_refs failed\n"); - ret = write(fd, ctrl, strlen(ctrl)); - if (ret != strlen(ctrl)) - ksft_exit_fail_msg("writing clear_refs failed\n"); - close(fd); -} - static void test_softdirty(void) { char *addr; diff --git a/tools/testing/selftests/vm/split_huge_page_test.c b/tools/testing/selftests/vm/split_huge_page_test.c index 52497b7b9f1db..6aa2b8253aeda 100644 --- a/tools/testing/selftests/vm/split_huge_page_test.c +++ b/tools/testing/selftests/vm/split_huge_page_test.c @@ -16,14 +16,13 @@ #include #include #include +#include "vm_util.h" uint64_t pagesize; unsigned int pageshift; uint64_t pmd_pagesize; -#define PMD_SIZE_PATH "/sys/kernel/mm/transparent_hugepage/hpage_pmd_size" #define SPLIT_DEBUGFS "/sys/kernel/debug/split_huge_pages" -#define SMAP_PATH "/proc/self/smaps" #define INPUT_MAX 80 #define PID_FMT "%d,0x%lx,0x%lx" @@ -51,30 +50,6 @@ int is_backed_by_thp(char *vaddr, int pagemap_file, int kpageflags_file) return 0; } - -static uint64_t read_pmd_pagesize(void) -{ - int fd; - char buf[20]; - ssize_t num_read; - - fd = open(PMD_SIZE_PATH, O_RDONLY); - if (fd == -1) { - perror("Open hpage_pmd_size failed"); - exit(EXIT_FAILURE); - } - num_read = read(fd, buf, 19); - if (num_read < 1) { - close(fd); - perror("Read hpage_pmd_size failed"); - exit(EXIT_FAILURE); - } - buf[num_read] = '\0'; - close(fd); - - return strtoul(buf, NULL, 10); -} - static int write_file(const char *path, const char *buf, size_t buflen) { int fd; @@ -113,58 +88,6 @@ static void write_debugfs(const char *fmt, ...) } } -#define MAX_LINE_LENGTH 500 - -static bool check_for_pattern(FILE *fp, const char *pattern, char *buf) -{ - while (fgets(buf, MAX_LINE_LENGTH, fp) != NULL) { - if (!strncmp(buf, pattern, strlen(pattern))) - return true; - } - return false; -} - -static uint64_t check_huge(void *addr) -{ - uint64_t thp = 0; - int ret; - FILE *fp; - char buffer[MAX_LINE_LENGTH]; - char addr_pattern[MAX_LINE_LENGTH]; - - ret = snprintf(addr_pattern, MAX_LINE_LENGTH, "%08lx-", - (unsigned long) addr); - if (ret >= MAX_LINE_LENGTH) { - printf("%s: Pattern is too long\n", __func__); - exit(EXIT_FAILURE); - } - - - fp = fopen(SMAP_PATH, "r"); - if (!fp) { - printf("%s: Failed to open file %s\n", __func__, SMAP_PATH); - exit(EXIT_FAILURE); - } - if (!check_for_pattern(fp, addr_pattern, buffer)) - goto err_out; - - /* - * Fetch the AnonHugePages: in the same block and check the number of - * hugepages. - */ - if (!check_for_pattern(fp, "AnonHugePages:", buffer)) - goto err_out; - - if (sscanf(buffer, "AnonHugePages:%10ld kB", &thp) != 1) { - printf("Reading smap error\n"); - exit(EXIT_FAILURE); - } - -err_out: - fclose(fp); - return thp; -} - void split_pmd_thp(void) { char *one_page; diff --git a/tools/testing/selftests/vm/vm_util.c b/tools/testing/selftests/vm/vm_util.c new file mode 100644 index 0000000000000..5beaebc8a88b4 --- /dev/null +++ b/tools/testing/selftests/vm/vm_util.c @@ -0,0 +1,107 @@ +// SPDX-License-Identifier: GPL-2.0 +#include +#include +#include "vm_util.h" + +#define PMD_SIZE_FILE_PATH "/sys/kernel/mm/transparent_hugepage/hpage_pmd_size" +#define SMAP_FILE_PATH "/proc/self/smaps" +#define MAX_LINE_LENGTH 500 + +uint64_t pagemap_get_entry(int fd, char *start) +{ + const unsigned long pfn = (unsigned long)start / getpagesize(); + uint64_t entry; + int ret; + + ret = pread(fd, &entry, sizeof(entry), pfn * sizeof(entry)); + if (ret != sizeof(entry)) + ksft_exit_fail_msg("reading pagemap failed\n"); + return entry; +} + +bool pagemap_is_softdirty(int fd, char *start) +{ + uint64_t entry = pagemap_get_entry(fd, start); + + // Check if dirty bit (55th bit) is set + return entry & 0x0080000000000000ull; +} + +void clear_softdirty(void) +{ + int ret; + const char *ctrl = "4"; + int fd = open("/proc/self/clear_refs", O_WRONLY); + + if (fd < 0) + ksft_exit_fail_msg("opening clear_refs failed\n"); + ret = write(fd, ctrl, strlen(ctrl)); + close(fd); + if (ret != strlen(ctrl)) + ksft_exit_fail_msg("writing clear_refs failed\n"); +} + +static bool check_for_pattern(FILE *fp, const char *pattern, char *buf) +{ + while (fgets(buf, MAX_LINE_LENGTH, fp) != NULL) { + if (!strncmp(buf, pattern, strlen(pattern))) + return true; + } + return false; +} + +uint64_t read_pmd_pagesize(void) +{ + int fd; + char buf[20]; + ssize_t num_read; + + fd = open(PMD_SIZE_FILE_PATH, O_RDONLY); + if (fd == -1) + ksft_exit_fail_msg("Open hpage_pmd_size failed\n"); + + num_read = read(fd, buf, 19); + if (num_read < 1) { + close(fd); + ksft_exit_fail_msg("Read hpage_pmd_size failed\n"); + } + buf[num_read] = '\0'; + close(fd); + + return strtoul(buf, NULL, 10); +} + +uint64_t check_huge(void *addr) +{ + uint64_t thp = 0; + int ret; + FILE *fp; + char buffer[MAX_LINE_LENGTH]; + char addr_pattern[MAX_LINE_LENGTH]; + + ret = snprintf(addr_pattern, MAX_LINE_LENGTH, "%08lx-", + (unsigned long) addr); + if (ret >= MAX_LINE_LENGTH) + ksft_exit_fail_msg("%s: Pattern is too long\n", __func__); + + fp = fopen(SMAP_FILE_PATH, "r"); + if (!fp) + ksft_exit_fail_msg("%s: Failed to open file %s\n", __func__, SMAP_FILE_PATH); + + if (!check_for_pattern(fp, addr_pattern, buffer)) + goto err_out; + + /* + * Fetch the AnonHugePages: in the same block and check the number of + * hugepages. + */ + if (!check_for_pattern(fp, "AnonHugePages:", buffer)) + goto err_out; + + if (sscanf(buffer, "AnonHugePages:%10ld kB", &thp) != 1) + ksft_exit_fail_msg("Reading smap error\n"); + +err_out: + fclose(fp); + return thp; +} diff --git a/tools/testing/selftests/vm/vm_util.h b/tools/testing/selftests/vm/vm_util.h new file mode 100644 index 0000000000000..e9f5a0f2be196 --- /dev/null +++ b/tools/testing/selftests/vm/vm_util.h @@ -0,0 +1,10 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#include +#include +#include "../kselftest.h" + +uint64_t pagemap_get_entry(int fd, char *start); +bool pagemap_is_softdirty(int fd, char *start); +void clear_softdirty(void); +uint64_t read_pmd_pagesize(void); +uint64_t check_huge(void *addr); From patchwork Thu Mar 17 10:33:22 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Muhammad Usama Anjum X-Patchwork-Id: 552921 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 28406C433F5 for ; Thu, 17 Mar 2022 10:34:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232640AbiCQKfY (ORCPT ); Thu, 17 Mar 2022 06:35:24 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58290 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232615AbiCQKfT (ORCPT ); Thu, 17 Mar 2022 06:35:19 -0400 Received: from bhuna.collabora.co.uk (bhuna.collabora.co.uk [46.235.227.227]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1040BE6160; Thu, 17 Mar 2022 03:34:03 -0700 (PDT) Received: from [127.0.0.1] (localhost [127.0.0.1]) (Authenticated sender: usama.anjum) with ESMTPSA id 7D6511F44CCB DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=collabora.com; s=mail; t=1647513241; bh=rI9DZ9jsH6eaZI5FatE4QcNepkJ88+Mje76GPlYvw8I=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=jFH5ZndPzsVi2tZw5UDkJLE1ixNvmShub6JnU23RGhysdZD2I/pLBby5g3s5LtBDh H8x0XFC9jcOeiFSWeNfSCgkqWpj0gdom4elq0xw/0Yn6q2rkPYhtbEa0blIiylvJSE w1HcAAaHnCyua7D2oLxOVrUGyhMjXCZnrOY+XWy8RflvKcTmiFIkVWdU4YbXBSzUp3 wUHbZ8pAF6ttmAEkZaIEtEKQjeIlq/tCzVzRrASGCU1as72E9E2Kehj7eRFm6nz/n5 9SpiS9s7l15/4lYdwU2wnoInspfRsCfDCrUJtGDnQUq6L73F+YNLpoHenXo8ldva8o GYZm3Fv71dFTw== From: Muhammad Usama Anjum To: Andrew Morton , Shuah Khan Cc: Gabriel Krisman Bertazi , usama.anjum@collabora.com, kernel@collabora.com, david@redhat.com, Will Deacon , linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-kselftest@vger.kernel.org Subject: [PATCH V5 2/2] selftests: vm: Add test for Soft-Dirty PTE bit Date: Thu, 17 Mar 2022 15:33:22 +0500 Message-Id: <20220317103323.94799-2-usama.anjum@collabora.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20220317103323.94799-1-usama.anjum@collabora.com> References: <20220317103323.94799-1-usama.anjum@collabora.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org From: Gabriel Krisman Bertazi This introduces three tests: 1) Sanity check soft dirty basic semantics: allocate area, clean, dirty, check if the SD bit is flipped. 2) Check VMA reuse: validate the VM_SOFTDIRTY usage 3) Check soft-dirty on huge pages This was motivated by Will Deacon's fix commit 912efa17e512 ("mm: proc: Invalidate TLB after clearing soft-dirty page state"). I was tracking the same issue that he fixed, and this test would have caught it. Cc: Will Deacon Signed-off-by: Gabriel Krisman Bertazi Signed-off-by: Muhammad Usama Anjum --- Andrew has dropped the V3 of this patch. Changes in V5: - Correct indentation of macros - Tested by reverting 912efa17e512 and one sub test failed - Updated the writing values to the memory and added a comment Changes in V4: Cosmetic changes Removed global variables Replaced ksft_print_msg with ksft_exit_fail_msg to exit the program at once Some other minor changes Correct the authorship of the patch Tests of soft dirty bit in this patch and in madv_populate.c are non-overlapping. madv_populate.c has only one soft-dirty bit test in the context of different advise (MADV_POPULATE_READ and MADV_POPULATE_WRITE). This new test adds more tests. Tab width of 8 has been used to align the macros. This alignment may look odd in shell or email. But it looks alright in editors. Test output: TAP version 13 1..5 ok 1 Test test_simple ok 2 Test test_vma_reuse reused memory location ok 3 Test test_vma_reuse dirty bit of previous page ok 4 Test test_hugepage huge page allocation ok 5 Test test_hugepage huge page dirty bit # Totals: pass:5 fail:0 xfail:0 xpass:0 skip:0 error:0 Or TAP version 13 1..5 ok 1 Test test_simple ok 2 Test test_vma_reuse reused memory location ok 3 Test test_vma_reuse dirty bit of previous page ok 4 # SKIP Test test_hugepage huge page allocation ok 5 # SKIP Test test_hugepage huge page dirty bit # Totals: pass:3 fail:0 xfail:0 xpass:0 skip:2 error:0 Changes in V3: Move test to selftests/vm Use kselftest macros Minor updates to make code more maintainable Add configurations in config file V2 of this patch: https://lore.kernel.org/lkml/20210603151518.2437813-1-krisman@collabora.com/ --- tools/testing/selftests/vm/.gitignore | 1 + tools/testing/selftests/vm/Makefile | 2 + tools/testing/selftests/vm/config | 2 + tools/testing/selftests/vm/soft-dirty.c | 146 ++++++++++++++++++++++++ 4 files changed, 151 insertions(+) create mode 100644 tools/testing/selftests/vm/soft-dirty.c diff --git a/tools/testing/selftests/vm/.gitignore b/tools/testing/selftests/vm/.gitignore index d7507f3c7c76a..3cb4fa771ec2a 100644 --- a/tools/testing/selftests/vm/.gitignore +++ b/tools/testing/selftests/vm/.gitignore @@ -29,5 +29,6 @@ write_to_hugetlbfs hmm-tests memfd_secret local_config.* +soft-dirty split_huge_page_test ksm_tests diff --git a/tools/testing/selftests/vm/Makefile b/tools/testing/selftests/vm/Makefile index 4e68edb26d6b6..f25eb30b5f0cb 100644 --- a/tools/testing/selftests/vm/Makefile +++ b/tools/testing/selftests/vm/Makefile @@ -47,6 +47,7 @@ TEST_GEN_FILES += on-fault-limit TEST_GEN_FILES += thuge-gen TEST_GEN_FILES += transhuge-stress TEST_GEN_FILES += userfaultfd +TEST_GEN_PROGS += soft-dirty TEST_GEN_PROGS += split_huge_page_test TEST_GEN_FILES += ksm_tests @@ -92,6 +93,7 @@ KSFT_KHDR_INSTALL := 1 include ../lib.mk $(OUTPUT)/madv_populate: vm_util.c +$(OUTPUT)/soft-dirty: vm_util.c $(OUTPUT)/split_huge_page_test: vm_util.c ifeq ($(MACHINE),x86_64) diff --git a/tools/testing/selftests/vm/config b/tools/testing/selftests/vm/config index 60e82da0de850..be087c4bc3961 100644 --- a/tools/testing/selftests/vm/config +++ b/tools/testing/selftests/vm/config @@ -4,3 +4,5 @@ CONFIG_TEST_VMALLOC=m CONFIG_DEVICE_PRIVATE=y CONFIG_TEST_HMM=m CONFIG_GUP_TEST=y +CONFIG_TRANSPARENT_HUGEPAGE=y +CONFIG_MEM_SOFT_DIRTY=y diff --git a/tools/testing/selftests/vm/soft-dirty.c b/tools/testing/selftests/vm/soft-dirty.c new file mode 100644 index 0000000000000..3153ebac6909b --- /dev/null +++ b/tools/testing/selftests/vm/soft-dirty.c @@ -0,0 +1,146 @@ +// SPDX-License-Identifier: GPL-2.0 +#include +#include +#include +#include +#include +#include +#include +#include "../kselftest.h" +#include "vm_util.h" + +#define PAGEMAP_FILE_PATH "/proc/self/pagemap" +#define TEST_ITERATIONS 10000 + +static void test_simple(int pagemap_fd, int pagesize) +{ + int i; + char *map; + + map = aligned_alloc(pagesize, pagesize); + if (!map) + ksft_exit_fail_msg("mmap failed\n"); + + clear_softdirty(); + + for (i = 0 ; i < TEST_ITERATIONS; i++) { + if (pagemap_is_softdirty(pagemap_fd, map) == 1) { + ksft_print_msg("dirty bit was 1, but should be 0 (i=%d)\n", i); + break; + } + + clear_softdirty(); + // Write something to the page to get the dirty bit enabled on the page + map[0] = i % 255; + + if (pagemap_is_softdirty(pagemap_fd, map) == 0) { + ksft_print_msg("dirty bit was 0, but should be 1 (i=%d)\n", i); + break; + } + + clear_softdirty(); + } + free(map); + + ksft_test_result(i == TEST_ITERATIONS, "Test %s\n", __func__); +} + +static void test_vma_reuse(int pagemap_fd, int pagesize) +{ + char *map, *map2; + + map = mmap(NULL, pagesize, (PROT_READ | PROT_WRITE), (MAP_PRIVATE | MAP_ANON), -1, 0); + if (map == MAP_FAILED) + ksft_exit_fail_msg("mmap failed"); + + clear_softdirty(); + + /* Write to the page before unmapping and map the same size region again to check + * if same memory region is gotten next time and if dirty bit is preserved across + * this type of allocations. + */ + map[0]++; + + munmap(map, pagesize); + + map2 = mmap(NULL, pagesize, (PROT_READ | PROT_WRITE), (MAP_PRIVATE | MAP_ANON), -1, 0); + if (map2 == MAP_FAILED) + ksft_exit_fail_msg("mmap failed"); + + ksft_test_result(map == map2, "Test %s reused memory location\n", __func__); + + ksft_test_result(pagemap_is_softdirty(pagemap_fd, map) != 0, + "Test %s dirty bit of previous page\n", __func__); + + munmap(map2, pagesize); +} + +static void test_hugepage(int pagemap_fd, int pagesize) +{ + char *map; + int i, ret; + size_t hpage_len = read_pmd_pagesize(); + + map = memalign(hpage_len, hpage_len); + if (!map) + ksft_exit_fail_msg("memalign failed\n"); + + ret = madvise(map, hpage_len, MADV_HUGEPAGE); + if (ret) + ksft_exit_fail_msg("madvise failed %d\n", ret); + + for (i = 0; i < hpage_len; i++) + map[i] = (char)i; + + if (check_huge(map)) { + ksft_test_result_pass("Test %s huge page allocation\n", __func__); + + clear_softdirty(); + for (i = 0 ; i < TEST_ITERATIONS ; i++) { + if (pagemap_is_softdirty(pagemap_fd, map) == 1) { + ksft_print_msg("dirty bit was 1, but should be 0 (i=%d)\n", i); + break; + } + + clear_softdirty(); + // Write something to the page to get the dirty bit enabled on the page + map[0] = i % 255; + + if (pagemap_is_softdirty(pagemap_fd, map) == 0) { + ksft_print_msg("dirty bit was 0, but should be 1 (i=%d)\n", i); + break; + } + clear_softdirty(); + } + + ksft_test_result(i == TEST_ITERATIONS, "Test %s huge page dirty bit\n", __func__); + } else { + // hugepage allocation failed. skip these tests + ksft_test_result_skip("Test %s huge page allocation\n", __func__); + ksft_test_result_skip("Test %s huge page dirty bit\n", __func__); + } + free(map); +} + +int main(int argc, char **argv) +{ + int pagemap_fd; + int pagesize; + + ksft_print_header(); + ksft_set_plan(5); + + pagemap_fd = open(PAGEMAP_FILE_PATH, O_RDONLY); + if (pagemap_fd < 0) + ksft_exit_fail_msg("Failed to open %s\n", PAGEMAP_FILE_PATH); + + pagesize = getpagesize(); + + test_simple(pagemap_fd, pagesize); + test_vma_reuse(pagemap_fd, pagesize); + test_hugepage(pagemap_fd, pagesize); + + close(pagemap_fd); + + return ksft_exit_pass(); +}