- Linux-kselftest-mirror - lists.linaro.org

[GIT PULL] KUnit fixes update for Linux 5.12-rc5

by Shuah Khan

Hi Linus, Please pull the following KUnit fixes update for Linux 5.12-rc5. This KUnit update for Linux 5.12-rc5 consists of two fixes to kunit tool from David Gow. diff is attached. thanks, -- Shuah ---------------------------------------------------------------- The following changes since commit a38fd8748464831584a19438cbb3082b5a2dab15: Linux 5.12-rc2 (2021-03-05 17:33:41 -0800) are available in the Git repository at: git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest tags/linux-kselftest-kunit-fixes-5.12-rc5.1 for you to fetch changes up to 7fd53f41f771d250eb08db08650940f017e37c26: kunit: tool: Disable PAGE_POISONING under --alltests (2021-03-11 14:37:37 -0700) ---------------------------------------------------------------- linux-kselftest-kunit-fixes-5.12-rc5.1 This KUnit update for Linux 5.12-rc5 consists of two fixes to kunit tool from David Gow. ---------------------------------------------------------------- David Gow (2): kunit: tool: Fix a python tuple typing error kunit: tool: Disable PAGE_POISONING under --alltests tools/testing/kunit/configs/broken_on_uml.config | 2 ++ tools/testing/kunit/kunit_config.py | 2 +- 2 files changed, 3 insertions(+), 1 deletion(-) ----------------------------------------------------------------

4 years, 3 months

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[PATCH] tools: testing: Remove duplicate include of sched.h

by Wan Jiabing

sched.h has been included at line 33. So we remove the duplicate one at line 36. Signed-off-by: Wan Jiabing <wanjiabing(a)vivo.com> --- tools/testing/selftests/powerpc/mm/tlbie_test.c | 1 - 1 file changed, 1 deletion(-) diff --git a/tools/testing/selftests/powerpc/mm/tlbie_test.c b/tools/testing/selftests/powerpc/mm/tlbie_test.c index f85a0938ab25..48344a74b212 100644 --- a/tools/testing/selftests/powerpc/mm/tlbie_test.c +++ b/tools/testing/selftests/powerpc/mm/tlbie_test.c @@ -33,7 +33,6 @@ #include <sched.h> #include <time.h> #include <stdarg.h> -#include <sched.h> #include <pthread.h> #include <signal.h> #include <sys/prctl.h> -- 2.25.1

4 years, 3 months

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[PATCH] tools: testing: inttypes.h is included twice

by Wan Jiabing

inttypes.h has been included at line 19. So we remove the duplicate one at line 23. Signed-off-by: Wan Jiabing <wanjiabing(a)vivo.com> --- tools/testing/selftests/powerpc/tm/tm-poison.c | 1 - 1 file changed, 1 deletion(-) diff --git a/tools/testing/selftests/powerpc/tm/tm-poison.c b/tools/testing/selftests/powerpc/tm/tm-poison.c index 29e5f26af7b9..27c083a03d1f 100644 --- a/tools/testing/selftests/powerpc/tm/tm-poison.c +++ b/tools/testing/selftests/powerpc/tm/tm-poison.c @@ -20,7 +20,6 @@ #include <sched.h> #include <sys/types.h> #include <signal.h> -#include <inttypes.h> #include "tm.h" -- 2.25.1

4 years, 3 months

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[PATCH] tools: testing: pthread.h is included twice

by Wan Jiabing

pthread.h has been included at line 17. So we remove the duplicate one at line 20. Signed-off-by: Wan Jiabing <wanjiabing(a)vivo.com> --- tools/testing/selftests/powerpc/tm/tm-vmx-unavail.c | 1 - 1 file changed, 1 deletion(-) diff --git a/tools/testing/selftests/powerpc/tm/tm-vmx-unavail.c b/tools/testing/selftests/powerpc/tm/tm-vmx-unavail.c index e2a0c07e8362..9ef37a9836ac 100644 --- a/tools/testing/selftests/powerpc/tm/tm-vmx-unavail.c +++ b/tools/testing/selftests/powerpc/tm/tm-vmx-unavail.c @@ -17,7 +17,6 @@ #include <pthread.h> #include <sys/mman.h> #include <unistd.h> -#include <pthread.h> #include "tm.h" #include "utils.h" -- 2.25.1

4 years, 3 months

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[PATCH bpf-next v2 0/2] add support for batched ops in LPM trie

by Pedro Tammela

The patch itself is straightforward thanks to the infrastructure that is already in-place. The tests follows the other '*_map_batch_ops' tests with minor tweaks. v1 -> v2: Fixes for checkpatch warnings Pedro Tammela (2): bpf: add support for batched operations in LPM trie maps bpf: selftests: add tests for batched ops in LPM trie maps kernel/bpf/lpm_trie.c | 3 + .../map_tests/lpm_trie_map_batch_ops.c (new) | 158 ++++++++++++++++++ 2 files changed, 161 insertions(+) create mode 100644 tools/testing/selftests/bpf/map_tests/lpm_trie_map_batch_ops.c -- 2.25.1

4 years, 3 months

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Re: [selftests] e48d82b67a: BUG_TestSlub_RZ_alloc(Not_tainted):Redzone_overwritten

by Vlastimil Babka

On 3/17/21 9:36 AM, kernel test robot wrote: > > > Greeting, > > FYI, we noticed the following commit (built with gcc-9): > > commit: e48d82b67a2b760eedf7b95ca15f41267496386c ("[PATCH 1/2] selftests: add a kselftest for SLUB debugging functionality") > url: https://github.com/0day-ci/linux/commits/glittao-gmail-com/selftests-add-a-… > base: https://git.kernel.org/cgit/linux/kernel/git/shuah/linux-kselftest.git next > > in testcase: trinity > version: trinity-static-i386-x86_64-f93256fb_2019-08-28 > with following parameters: > > group: group-04 > > test-description: Trinity is a linux system call fuzz tester. > test-url: http://codemonkey.org.uk/projects/trinity/ > > > on test machine: qemu-system-i386 -enable-kvm -cpu SandyBridge -smp 2 -m 8G > > caused below changes (please refer to attached dmesg/kmsg for entire log/backtrace): > > > +---------------------------------------------------------------------------------------------------------------+-----------+------------+ > | | v5.12-rc2 | e48d82b67a | > +---------------------------------------------------------------------------------------------------------------+-----------+------------+ > | BUG_TestSlub_RZ_alloc(Not_tainted):Redzone_overwritten | 0 | 69 | > | INFO:0x(ptrval)-0x(ptrval)@offset=#.First_byte#instead_of | 0 | 69 | > | INFO:Allocated_in_resiliency_test_age=#cpu=#pid= | 0 | 69 | > | INFO:Slab0x(ptrval)objects=#used=#fp=0x(ptrval)flags= | 0 | 69 | > | INFO:Object0x(ptrval)@offset=#fp=0x(ptrval) | 0 | 69 | > | BUG_TestSlub_next_ptr_free(Tainted:G_B):Freechain_corrupt | 0 | 69 | > | INFO:Freed_in_resiliency_test_age=#cpu=#pid= | 0 | 69 | > | BUG_TestSlub_next_ptr_free(Tainted:G_B):Wrong_object_count.Counter_is#but_counted_were | 0 | 69 | > | BUG_TestSlub_next_ptr_free(Tainted:G_B):Redzone_overwritten | 0 | 69 | > | BUG_TestSlub_next_ptr_free(Tainted:G_B):Objects_remaining_in_TestSlub_next_ptr_free_on__kmem_cache_shutdown() | 0 | 69 | > | INFO:Object0x(ptrval)@offset= | 0 | 69 | > | BUG_TestSlub_1th_word_free(Tainted:G_B):Poison_overwritten | 0 | 69 | > | BUG_TestSlub_50th_word_free(Tainted:G_B):Poison_overwritten | 0 | 69 | > | BUG_TestSlub_RZ_free(Tainted:G_B):Redzone_overwritten | 0 | 69 | > +---------------------------------------------------------------------------------------------------------------+-----------+------------+ > > > If you fix the issue, kindly add following tag > Reported-by: kernel test robot <oliver.sang(a)intel.com> > > > > [ 22.154049] random: get_random_u32 called from __kmem_cache_create+0x23/0x3e0 with crng_init=0 > [ 22.154070] random: get_random_u32 called from cache_random_seq_create+0x7c/0x140 with crng_init=0 > [ 22.154167] random: get_random_u32 called from allocate_slab+0x155/0x5e0 with crng_init=0 > [ 22.154690] test_slub: 1. kmem_cache: Clobber Redzone 0x12->0x(ptrval) > [ 22.164499] ============================================================================= > [ 22.166629] BUG TestSlub_RZ_alloc (Not tainted): Redzone overwritten > [ 22.168179] ----------------------------------------------------------------------------- > [ 22.168179] > [ 22.168372] Disabling lock debugging due to kernel taint > [ 22.168372] INFO: 0x(ptrval)-0x(ptrval) @offset=1064. First byte 0x12 instead of 0xcc > [ 22.168372] INFO: Allocated in resiliency_test+0x47/0x1be age=3 cpu=0 pid=1 > [ 22.168372] __slab_alloc+0x57/0x80 > [ 22.168372] kmem_cache_alloc (kbuild/src/consumer/mm/slub.c:2871 kbuild/src/consumer/mm/slub.c:2915 kbuild/src/consumer/mm/slub.c:2920) > [ 22.168372] resiliency_test (kbuild/src/consumer/lib/test_slub.c:34 kbuild/src/consumer/lib/test_slub.c:107) > [ 22.168372] test_slub_init (kbuild/src/consumer/lib/test_slub.c:124) > [ 22.168372] do_one_initcall (kbuild/src/consumer/init/main.c:1226) > [ 22.168372] kernel_init_freeable (kbuild/src/consumer/init/main.c:1298 kbuild/src/consumer/init/main.c:1315 kbuild/src/consumer/init/main.c:1335 kbuild/src/consumer/init/main.c:1537) > [ 22.168372] kernel_init (kbuild/src/consumer/init/main.c:1426) > [ 22.168372] ret_from_fork (kbuild/src/consumer/arch/x86/entry/entry_32.S:856) > [ 22.168372] INFO: Slab 0x(ptrval) objects=16 used=1 fp=0x(ptrval) flags=0x40000201 > [ 22.168372] INFO: Object 0x(ptrval) @offset=1000 fp=0x(ptrval) > [ 22.168372] > [ 22.168372] Redzone (ptrval): cc cc cc cc cc cc cc cc ........ > [ 22.168372] Object (ptrval): 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk > [ 22.168372] Object (ptrval): 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b a5 kkkkkkkkkkkkkkk. > [ 22.168372] Redzone (ptrval): 12 cc cc cc .... > [ 22.168372] Padding (ptrval): 5a 5a 5a 5a 5a 5a 5a 5a ZZZZZZZZ > [ 22.168372] CPU: 0 PID: 1 Comm: swapper/0 Tainted: G B 5.12.0-rc2-00001-ge48d82b67a2b #1 > [ 22.168372] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014 > [ 22.168372] Call Trace: > [ 22.168372] dump_stack (kbuild/src/consumer/lib/dump_stack.c:122) > [ 22.168372] print_trailer (kbuild/src/consumer/mm/slub.c:737) > [ 22.168372] check_bytes_and_report.cold (kbuild/src/consumer/mm/slub.c:807) > [ 22.168372] check_object (kbuild/src/consumer/mm/slub.c:914) > [ 22.168372] validate_slab (kbuild/src/consumer/mm/slub.c:4635) Hm but in this case the output means the tested functionality (slub debugging) is working as intended. So what can we do? Indicate/teach somehow to the bot that this is OK? Does kselftest have some support for this? Or silence the validation output for testing purposes? (I would prefer not to) Thanks, Vlastimil

4 years, 3 months

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[PATCH v5 1/2] mm: huge_memory: a new debugfs interface for splitting THP tests.

by Zi Yan

From: Zi Yan <ziy(a)nvidia.com> We did not have a direct user interface of splitting the compound page backing a THP and there is no need unless we want to expose the THP implementation details to users. Make <debugfs>/split_huge_pages accept a new command to do that. By writing "<pid>,<vaddr_start>,<vaddr_end>" to <debugfs>/split_huge_pages, THPs within the given virtual address range from the process with the given pid are split. It is used to test split_huge_page function. In addition, a selftest program is added to tools/testing/selftests/vm to utilize the interface by splitting PMD THPs and PTE-mapped THPs. This does not change the old behavior, i.e., writing 1 to the interface to split all THPs in the system. Changelog: >From v5: 1. Skipped special VMAs and other fixes. (suggested by Yang Shi) >From v4: 1. Fixed the error code return issue, spotted by kernel test robot <lkp(a)intel.com>. >From v3: 1. Factored out split huge pages in the given pid code to a separate function. 2. Added the missing put_page for not split pages. 3. pr_debug -> pr_info, make reading results simpler. >From v2: 1. Reused existing <debugfs>/split_huge_pages interface. (suggested by Yang Shi) >From v1: 1. Removed unnecessary calling to vma_migratable, spotted by kernel test robot <lkp(a)intel.com>. 2. Dropped the use of find_mm_struct and code it directly, since there is no need for the permission check in that function and the function is only available when migration is on. 3. Added some comments in the selftest program to clarify how PTE-mapped THPs are formed. Signed-off-by: Zi Yan <ziy(a)nvidia.com> --- mm/huge_memory.c | 143 +++++++- tools/testing/selftests/vm/.gitignore | 1 + tools/testing/selftests/vm/Makefile | 1 + .../selftests/vm/split_huge_page_test.c | 318 ++++++++++++++++++ 4 files changed, 456 insertions(+), 7 deletions(-) create mode 100644 tools/testing/selftests/vm/split_huge_page_test.c diff --git a/mm/huge_memory.c b/mm/huge_memory.c index bff92dea5ab3..9bf9bc489228 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -7,6 +7,7 @@ #include <linux/mm.h> #include <linux/sched.h> +#include <linux/sched/mm.h> #include <linux/sched/coredump.h> #include <linux/sched/numa_balancing.h> #include <linux/highmem.h> @@ -2922,16 +2923,14 @@ static struct shrinker deferred_split_shrinker = { }; #ifdef CONFIG_DEBUG_FS -static int split_huge_pages_set(void *data, u64 val) +static void split_huge_pages_all(void) { struct zone *zone; struct page *page; unsigned long pfn, max_zone_pfn; unsigned long total = 0, split = 0; - if (val != 1) - return -EINVAL; - + pr_info("Split all THPs\n"); for_each_populated_zone(zone) { max_zone_pfn = zone_end_pfn(zone); for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++) { @@ -2959,11 +2958,141 @@ static int split_huge_pages_set(void *data, u64 val) } pr_info("%lu of %lu THP split\n", split, total); +} - return 0; +static int split_huge_pages_pid(int pid, unsigned long vaddr_start, + unsigned long vaddr_end) +{ + int ret = 0; + struct task_struct *task; + struct mm_struct *mm; + unsigned long total = 0, split = 0; + unsigned long addr; + + vaddr_start &= PAGE_MASK; + vaddr_end &= PAGE_MASK; + + /* Find the task_struct from pid */ + rcu_read_lock(); + task = find_task_by_vpid(pid); + if (!task) { + rcu_read_unlock(); + ret = -ESRCH; + goto out; + } + get_task_struct(task); + rcu_read_unlock(); + + /* Find the mm_struct */ + mm = get_task_mm(task); + put_task_struct(task); + + if (!mm) { + ret = -EINVAL; + goto out; + } + + pr_info("Split huge pages in pid: %d, vaddr: [0x%lx - 0x%lx]\n", + pid, vaddr_start, vaddr_end); + + mmap_read_lock(mm); + /* + * always increase addr by PAGE_SIZE, since we could have a PTE page + * table filled with PTE-mapped THPs, each of which is distinct. + */ + for (addr = vaddr_start; addr < vaddr_end; addr += PAGE_SIZE) { + struct vm_area_struct *vma = find_vma(mm, addr); + unsigned int follflags; + struct page *page; + + if (!vma || addr < vma->vm_start) + break; + + /* skip special VMA and hugetlb VMA */ + if (vma_is_special_huge(vma) || is_vm_hugetlb_page(vma)) { + addr = vma->vm_end; + continue; + } + + /* FOLL_DUMP to ignore special (like zero) pages */ + follflags = FOLL_GET | FOLL_DUMP; + page = follow_page(vma, addr, follflags); + + if (IS_ERR(page)) + continue; + if (!page) + continue; + + if (!is_transparent_hugepage(page)) + goto next; + + total++; + if (!can_split_huge_page(compound_head(page), NULL)) + goto next; + + if (!trylock_page(page)) + goto next; + + if (!split_huge_page(page)) + split++; + + unlock_page(page); +next: + put_page(page); + } + mmap_read_unlock(mm); + mmput(mm); + + pr_info("%lu of %lu THP split\n", split, total); + +out: + return ret; } -DEFINE_DEBUGFS_ATTRIBUTE(split_huge_pages_fops, NULL, split_huge_pages_set, - "%llu\n"); + +static ssize_t split_huge_pages_write(struct file *file, const char __user *buf, + size_t count, loff_t *ppops) +{ + static DEFINE_MUTEX(split_debug_mutex); + ssize_t ret; + char input_buf[80]; /* hold pid, start_vaddr, end_vaddr */ + int pid; + unsigned long vaddr_start, vaddr_end; + + ret = mutex_lock_interruptible(&split_debug_mutex); + if (ret) + return ret; + + ret = -EFAULT; + + memset(input_buf, 0, 80); + if (copy_from_user(input_buf, buf, min_t(size_t, count, 80))) + goto out; + + input_buf[79] = '\0'; + ret = sscanf(input_buf, "%d,0x%lx,0x%lx", &pid, &vaddr_start, &vaddr_end); + if (ret == 1 && pid == 1) { + split_huge_pages_all(); + ret = strlen(input_buf); + goto out; + } else if (ret != 3) { + ret = -EINVAL; + goto out; + } + + ret = split_huge_pages_pid(pid, vaddr_start, vaddr_end); + if (!ret) + ret = strlen(input_buf); +out: + mutex_unlock(&split_debug_mutex); + return ret; + +} + +static const struct file_operations split_huge_pages_fops = { + .owner = THIS_MODULE, + .write = split_huge_pages_write, + .llseek = no_llseek, +}; static int __init split_huge_pages_debugfs(void) { diff --git a/tools/testing/selftests/vm/.gitignore b/tools/testing/selftests/vm/.gitignore index 9a35c3f6a557..1f651e85ed60 100644 --- a/tools/testing/selftests/vm/.gitignore +++ b/tools/testing/selftests/vm/.gitignore @@ -22,3 +22,4 @@ map_fixed_noreplace write_to_hugetlbfs hmm-tests local_config.* +split_huge_page_test diff --git a/tools/testing/selftests/vm/Makefile b/tools/testing/selftests/vm/Makefile index d42115e4284d..4cbc91d6869f 100644 --- a/tools/testing/selftests/vm/Makefile +++ b/tools/testing/selftests/vm/Makefile @@ -42,6 +42,7 @@ 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 ifeq ($(MACHINE),x86_64) CAN_BUILD_I386 := $(shell ./../x86/check_cc.sh $(CC) ../x86/trivial_32bit_program.c -m32) diff --git a/tools/testing/selftests/vm/split_huge_page_test.c b/tools/testing/selftests/vm/split_huge_page_test.c new file mode 100644 index 000000000000..2c0c18e60c57 --- /dev/null +++ b/tools/testing/selftests/vm/split_huge_page_test.c @@ -0,0 +1,318 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * A test of splitting PMD THPs and PTE-mapped THPs from a specified virtual + * address range in a process via <debugfs>/split_huge_pages interface. + */ + +#define _GNU_SOURCE +#include <stdio.h> +#include <stdlib.h> +#include <unistd.h> +#include <inttypes.h> +#include <string.h> +#include <fcntl.h> +#include <sys/mman.h> +#include <malloc.h> +#include <stdbool.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 PFN_MASK ((1UL<<55)-1) +#define KPF_THP (1UL<<22) + +int is_backed_by_thp(char *vaddr, int pagemap_file, int kpageflags_file) +{ + uint64_t paddr; + uint64_t page_flags; + + if (pagemap_file) { + pread(pagemap_file, &paddr, sizeof(paddr), + ((long)vaddr >> pageshift) * sizeof(paddr)); + + if (kpageflags_file) { + pread(kpageflags_file, &page_flags, sizeof(page_flags), + (paddr & PFN_MASK) * sizeof(page_flags)); + + return !!(page_flags & KPF_THP); + } + } + 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; + ssize_t numwritten; + + fd = open(path, O_WRONLY); + if (fd == -1) + return 0; + + numwritten = write(fd, buf, buflen - 1); + close(fd); + if (numwritten < 1) + return 0; + + return (unsigned int) numwritten; +} + +static void write_debugfs(int pid, uint64_t vaddr_start, uint64_t vaddr_end) +{ + char input[INPUT_MAX]; + int ret; + + ret = snprintf(input, INPUT_MAX, "%d,0x%lx,0x%lx", pid, vaddr_start, + vaddr_end); + if (ret >= INPUT_MAX) { + printf("%s: Debugfs input is too long\n", __func__); + exit(EXIT_FAILURE); + } + + if (!write_file(SPLIT_DEBUGFS, input, ret + 1)) { + perror(SPLIT_DEBUGFS); + exit(EXIT_FAILURE); + } +} + +#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; + size_t len = 4 * pmd_pagesize; + uint64_t thp_size; + size_t i; + + one_page = memalign(pmd_pagesize, len); + + if (!one_page) { + printf("Fail to allocate memory\n"); + exit(EXIT_FAILURE); + } + + madvise(one_page, len, MADV_HUGEPAGE); + + for (i = 0; i < len; i++) + one_page[i] = (char)i; + + thp_size = check_huge(one_page); + if (!thp_size) { + printf("No THP is allocated\n"); + exit(EXIT_FAILURE); + } + + /* split all THPs */ + write_debugfs(getpid(), (uint64_t)one_page, (uint64_t)one_page + len); + + for (i = 0; i < len; i++) + if (one_page[i] != (char)i) { + printf("%ld byte corrupted\n", i); + exit(EXIT_FAILURE); + } + + + thp_size = check_huge(one_page); + if (thp_size) { + printf("Still %ld kB AnonHugePages not split\n", thp_size); + exit(EXIT_FAILURE); + } + + printf("Split huge pages successful\n"); + free(one_page); +} + +void split_pte_mapped_thp(void) +{ + char *one_page, *pte_mapped, *pte_mapped2; + size_t len = 4 * pmd_pagesize; + uint64_t thp_size; + size_t i; + const char *pagemap_template = "/proc/%d/pagemap"; + const char *kpageflags_proc = "/proc/kpageflags"; + char pagemap_proc[255]; + int pagemap_fd; + int kpageflags_fd; + + if (snprintf(pagemap_proc, 255, pagemap_template, getpid()) < 0) { + perror("get pagemap proc error"); + exit(EXIT_FAILURE); + } + pagemap_fd = open(pagemap_proc, O_RDONLY); + + if (pagemap_fd == -1) { + perror("read pagemap:"); + exit(EXIT_FAILURE); + } + + kpageflags_fd = open(kpageflags_proc, O_RDONLY); + + if (kpageflags_fd == -1) { + perror("read kpageflags:"); + exit(EXIT_FAILURE); + } + + one_page = mmap((void *)(1UL << 30), len, PROT_READ | PROT_WRITE, + MAP_ANONYMOUS | MAP_PRIVATE, -1, 0); + + madvise(one_page, len, MADV_HUGEPAGE); + + for (i = 0; i < len; i++) + one_page[i] = (char)i; + + thp_size = check_huge(one_page); + if (!thp_size) { + printf("No THP is allocated\n"); + exit(EXIT_FAILURE); + } + + /* remap the first pagesize of first THP */ + pte_mapped = mremap(one_page, pagesize, pagesize, MREMAP_MAYMOVE); + + /* remap the Nth pagesize of Nth THP */ + for (i = 1; i < 4; i++) { + pte_mapped2 = mremap(one_page + pmd_pagesize * i + pagesize * i, + pagesize, pagesize, + MREMAP_MAYMOVE|MREMAP_FIXED, + pte_mapped + pagesize * i); + if (pte_mapped2 == (char *)-1) { + perror("mremap failed"); + exit(EXIT_FAILURE); + } + } + + /* smap does not show THPs after mremap, use kpageflags instead */ + thp_size = 0; + for (i = 0; i < pagesize * 4; i++) + if (i % pagesize == 0 && + is_backed_by_thp(&pte_mapped[i], pagemap_fd, kpageflags_fd)) + thp_size++; + + if (thp_size != 4) { + printf("Some THPs are missing during mremap\n"); + exit(EXIT_FAILURE); + } + + /* split all remapped THPs */ + write_debugfs(getpid(), (uint64_t)pte_mapped, + (uint64_t)pte_mapped + pagesize * 4); + + /* smap does not show THPs after mremap, use kpageflags instead */ + thp_size = 0; + for (i = 0; i < pagesize * 4; i++) { + if (pte_mapped[i] != (char)i) { + printf("%ld byte corrupted\n", i); + exit(EXIT_FAILURE); + } + if (i % pagesize == 0 && + is_backed_by_thp(&pte_mapped[i], pagemap_fd, kpageflags_fd)) + thp_size++; + } + + if (thp_size) { + printf("Still %ld THPs not split\n", thp_size); + exit(EXIT_FAILURE); + } + + printf("Split PTE-mapped huge pages successful\n"); + munmap(one_page, len); + close(pagemap_fd); + close(kpageflags_fd); +} + +int main(int argc, char **argv) +{ + if (geteuid() != 0) { + printf("Please run the benchmark as root\n"); + exit(EXIT_FAILURE); + } + + pagesize = getpagesize(); + pageshift = ffs(pagesize) - 1; + pmd_pagesize = read_pmd_pagesize(); + + split_pmd_thp(); + split_pte_mapped_thp(); + + return 0; +} -- 2.30.2

4 years, 3 months

3
5
0 0

[PATCH] kselftest/arm64: sve: Do not use non-canonical FFR register value

by Andre Przywara

The "First Fault Register" (FFR) is an SVE register that mimics a predicate register, but clears bits when a load or store fails to handle an element of a vector. The supposed usage scenario is to initialise this register (using SETFFR), then *read* it later on to learn about elements that failed to load or store. Explicit writes to this register using the WRFFR instruction are only supposed to *restore* values previously read from the register (for context-switching only). As the manual describes, this register holds only certain values, it: "... contains a monotonic predicate value, in which starting from bit 0 there are zero or more 1 bits, followed only by 0 bits in any remaining bit positions." Any other value is UNPREDICTABLE and is not supposed to be "restored" into the register. The SVE test currently tries to write a signature pattern into the register, which is *not* a canonical FFR value. Apparently the existing setups treat UNPREDICTABLE as "read-as-written", but a new implementation actually only stores canonical values. As a consequence, the sve-test fails immediately when comparing the FFR value: ----------- # ./sve-test Vector length: 128 bits PID: 207 Mismatch: PID=207, iteration=0, reg=48 Expected [cf00] Got [0f00] Aborted ----------- Fix this by only populating the FFR with proper canonical values. Effectively the requirement described above limits us to 17 unique values over 16 bits worth of FFR, so we condense our signature down to 4 bits (2 bits from the PID, 2 bits from the generation) and generate the canonical pattern from it. Any bits describing elements above the minimum 128 bit are set to 0. This aligns the FFR usage to the architecture and fixes the test on microarchitectures implementing FFR in a more restricted way. Signed-off-by: Andre Przywara <andre.przywara(a)arm.com> --- tools/testing/selftests/arm64/fp/sve-test.S | 22 ++++++++++++++++----- 1 file changed, 17 insertions(+), 5 deletions(-) diff --git a/tools/testing/selftests/arm64/fp/sve-test.S b/tools/testing/selftests/arm64/fp/sve-test.S index 9210691aa998..e3e08d9c7020 100644 --- a/tools/testing/selftests/arm64/fp/sve-test.S +++ b/tools/testing/selftests/arm64/fp/sve-test.S @@ -284,16 +284,28 @@ endfunction // Set up test pattern in the FFR // x0: pid // x2: generation +// +// We need to generate a canonical FFR value, which consists of a number of +// low "1" bits, followed by a number of zeros. This gives us 17 unique values +// per 16 bits of FFR, so we create a 4 bit signature out of the PID and +// generation, and use that as the initial number of ones in the pattern. +// We fill the upper lanes of FFR with zeros. // Beware: corrupts P0. function setup_ffr mov x4, x30 - bl pattern + and w0, w0, #0x3 + bfi w0, w2, #2, #2 + mov w1, #1 + lsl w1, w1, w0 + sub w1, w1, #1 + ldr x0, =ffrref - ldr x1, =scratch - rdvl x2, #1 - lsr x2, x2, #3 - bl memcpy + strh w1, [x0], 2 + rdvl x1, #1 + lsr x1, x1, #3 + sub x1, x1, #2 + bl memclr mov x0, #0 ldr x1, =ffrref -- 2.25.1

4 years, 3 months

3
2
0 0

[RFC 0/2] CPU-Idle latency selftest framework

by Pratik Rajesh Sampat

A kernel module + userspace driver to estimate the wakeup latency caused by going into stop states. The motivation behind this program is to find significant deviations behind advertised latency and residency values. The patchset measures latencies for two kinds of events. IPIs and Timers As this is a software-only mechanism, there will additional latencies of the kernel-firmware-hardware interactions. To account for that, the program also measures a baseline latency on a 100 percent loaded CPU and the latencies achieved must be in view relative to that. To achieve this, we introduce a kernel module and expose its control knobs through the debugfs interface that the selftests can engage with. The kernel module provides the following interfaces within /sys/kernel/debug/latency_test/ for, IPI test: ipi_cpu_dest = Destination CPU for the IPI ipi_cpu_src = Origin of the IPI ipi_latency_ns = Measured latency time in ns Timeout test: timeout_cpu_src = CPU on which the timer to be queued timeout_expected_ns = Timer duration timeout_diff_ns = Difference of actual duration vs expected timer Sample output on a POWER9 system is as follows: # --IPI Latency Test--- # Baseline Average IPI latency(ns): 3114 # Observed Average IPI latency(ns) - State0: 3265 # Observed Average IPI latency(ns) - State1: 3507 # Observed Average IPI latency(ns) - State2: 3739 # Observed Average IPI latency(ns) - State3: 3807 # Observed Average IPI latency(ns) - State4: 17070 # Observed Average IPI latency(ns) - State5: 1038174 # Observed Average IPI latency(ns) - State6: 1068784 # # --Timeout Latency Test-- # Baseline Average timeout diff(ns): 1420 # Observed Average timeout diff(ns) - State0: 1640 # Observed Average timeout diff(ns) - State1: 1764 # Observed Average timeout diff(ns) - State2: 1715 # Observed Average timeout diff(ns) - State3: 1845 # Observed Average timeout diff(ns) - State4: 16581 # Observed Average timeout diff(ns) - State5: 939977 # Observed Average timeout diff(ns) - State6: 1073024 Things to keep in mind: 1. This kernel module + bash driver does not guarantee idleness on a core when the IPI and the Timer is armed. It only invokes sleep and hopes that the core is idle once the IPI/Timer is invoked onto it. Hence this program must be run on a completely idle system for best results 2. Even on a completely idle system, there maybe book-keeping tasks or jitter tasks that can run on the core we want idle. This can create outliers in the latency measurement. Thankfully, these outliers should be large enough to easily weed them out. 3. A userspace only selftest variant was also sent out as RFC based on suggestions over the previous patchset to simply the kernel complexeity. However, a userspace only approach had more noise in the latency measurement due to userspace-kernel interactions which led to run to run variance and a lesser accurate test. Another downside of the nature of a userspace program is that it takes orders of magnitude longer to complete a full system test compared to the kernel framework. RFC patch: https://lkml.org/lkml/2020/9/2/356 4. For Intel Systems, the Timer based latencies don't exactly give out the measure of idle latencies. This is because of a hardware optimization mechanism that pre-arms a CPU when a timer is set to wakeup. That doesn't make this metric useless for Intel systems, it just means that is measuring IPI/Timer responding latency rather than idle wakeup latencies. (Source: https://lkml.org/lkml/2020/9/2/610) For solution to this problem, a hardware based latency analyzer is devised by Artem Bityutskiy from Intel. https://youtu.be/Opk92aQyvt0?t=8266 https://intel.github.io/wult/ Pratik Rajesh Sampat (2): cpuidle: Extract IPI based and timer based wakeup latency from idle states selftest/cpuidle: Add support for cpuidle latency measurement drivers/cpuidle/Makefile | 1 + drivers/cpuidle/test-cpuidle_latency.c | 157 ++++++++++ lib/Kconfig.debug | 10 + tools/testing/selftests/Makefile | 1 + tools/testing/selftests/cpuidle/Makefile | 6 + tools/testing/selftests/cpuidle/cpuidle.sh | 316 +++++++++++++++++++++ tools/testing/selftests/cpuidle/settings | 2 + 7 files changed, 493 insertions(+) create mode 100644 drivers/cpuidle/test-cpuidle_latency.c create mode 100644 tools/testing/selftests/cpuidle/Makefile create mode 100755 tools/testing/selftests/cpuidle/cpuidle.sh create mode 100644 tools/testing/selftests/cpuidle/settings -- 2.17.1

4 years, 3 months

3
6
0 0

[RFC PATCH v4 0/9] KVM: selftests: some improvement and a new test for kvm page table

by Yanan Wang

Hi, This v4 series can mainly include two parts. Based on kvm queue branch: https://git.kernel.org/pub/scm/virt/kvm/kvm.git/log/?h=queue Links of v1: https://lore.kernel.org/lkml/20210208090841.333724-1-wangyanan55@huawei.com/ Links of v2: https://lore.kernel.org/lkml/20210225055940.18748-1-wangyanan55@huawei.com/ Links of v3: https://lore.kernel.org/lkml/20210301065916.11484-1-wangyanan55@huawei.com/ In the first part, all the known hugetlb backing src types specified with different hugepage sizes are listed, so that we can specify use of hugetlb source of the exact granularity that we want, instead of the system default ones. And as all the known hugetlb page sizes are listed, it's appropriate for all architectures. Besides, a helper that can get granularity of different backing src types(anonumous/thp/hugetlb) is added, so that we can use the accurate backing src granularity for kinds of alignment or guest memory accessing of vcpus. In the second part, a new test is added: This test is added to serve as a performance tester and a bug reproducer for kvm page table code (GPA->HPA mappings), it gives guidance for the people trying to make some improvement for kvm. And the following explains what we can exactly do through this test. The function guest_code() can cover the conditions where a single vcpu or multiple vcpus access guest pages within the same memory region, in three VM stages(before dirty logging, during dirty logging, after dirty logging). Besides, the backing src memory type(ANONYMOUS/THP/HUGETLB) of the tested memory region can be specified by users, which means normal page mappings or block mappings can be chosen by users to be created in the test. If ANONYMOUS memory is specified, kvm will create normal page mappings for the tested memory region before dirty logging, and update attributes of the page mappings from RO to RW during dirty logging. If THP/HUGETLB memory is specified, kvm will create block mappings for the tested memory region before dirty logging, and split the blcok mappings into normal page mappings during dirty logging, and coalesce the page mappings back into block mappings after dirty logging is stopped. So in summary, as a performance tester, this test can present the performance of kvm creating/updating normal page mappings, or the performance of kvm creating/splitting/recovering block mappings, through execution time. When we need to coalesce the page mappings back to block mappings after dirty logging is stopped, we have to firstly invalidate *all* the TLB entries for the page mappings right before installation of the block entry, because a TLB conflict abort error could occur if we can't invalidate the TLB entries fully. We have hit this TLB conflict twice on aarch64 software implementation and fixed it. As this test can imulate process from dirty logging enabled to dirty logging stopped of a VM with block mappings, so it can also reproduce this TLB conflict abort due to inadequate TLB invalidation when coalescing tables. Links about the TLB conflict abort: https://lore.kernel.org/lkml/20201201201034.116760-3-wangyanan55@huawei.com/ --- Change logs: v3->v4: - Add a helper to get system default hugetlb page size - Add tags of Reviewed-by of Ben in the patches v2->v3: - Add tags of Suggested-by, Reviewed-by in the patches - Add a generic micro to get hugetlb page sizes - Some changes for suggestions about v2 series v1->v2: - Add a patch to sync header files - Add helpers to get granularity of different backing src types - Some changes for suggestions about v1 series --- Yanan Wang (9): tools headers: sync headers of asm-generic/hugetlb_encode.h tools headers: Add a macro to get HUGETLB page sizes for mmap KVM: selftests: Use flag CLOCK_MONOTONIC_RAW for timing KVM: selftests: Make a generic helper to get vm guest mode strings KVM: selftests: Add a helper to get system configured THP page size KVM: selftests: Add a helper to get system default hugetlb page size KVM: selftests: List all hugetlb src types specified with page sizes KVM: selftests: Adapt vm_userspace_mem_region_add to new helpers KVM: selftests: Add a test for kvm page table code include/uapi/linux/mman.h | 2 + tools/include/asm-generic/hugetlb_encode.h | 3 + tools/include/uapi/linux/mman.h | 2 + tools/testing/selftests/kvm/Makefile | 3 + .../selftests/kvm/demand_paging_test.c | 8 +- .../selftests/kvm/dirty_log_perf_test.c | 14 +- .../testing/selftests/kvm/include/kvm_util.h | 4 +- .../testing/selftests/kvm/include/test_util.h | 21 +- .../selftests/kvm/kvm_page_table_test.c | 476 ++++++++++++++++++ tools/testing/selftests/kvm/lib/kvm_util.c | 59 ++- tools/testing/selftests/kvm/lib/test_util.c | 122 ++++- tools/testing/selftests/kvm/steal_time.c | 4 +- 12 files changed, 659 insertions(+), 59 deletions(-) create mode 100644 tools/testing/selftests/kvm/kvm_page_table_test.c -- 2.19.1

4 years, 3 months

3
24
0 0

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