[LTP] [PATCH 02/13] Hugetlb: Migrating libhugetlbfs mmap-cow
Li Wang
liwang@redhat.com
Mon Dec 26 07:57:12 CET 2022
On Sun, Dec 25, 2022 at 11:42 PM Tarun Sahu <tsahu@linux.ibm.com> wrote:
> Migrating the libhugetlbfs/testcases/mmap-cow.c test
>
> Test Description: Tests copy-on-write semantics of large pages where a
> number of threads map the same file with the MAP_PRIVATE flag. The threads
> then write into their copy of the mapping and recheck the contents to
> ensure they were not corrupted by the other threads.
>
> Signed-off-by: Tarun Sahu <tsahu@linux.ibm.com>
> ---
> runtest/hugetlb | 1 +
> testcases/kernel/mem/.gitignore | 1 +
> .../kernel/mem/hugetlb/hugemmap/hugemmap21.c | 131 ++++++++++++++++++
> 3 files changed, 133 insertions(+)
> create mode 100644 testcases/kernel/mem/hugetlb/hugemmap/hugemmap21.c
>
> diff --git a/runtest/hugetlb b/runtest/hugetlb
> index 2dffa8421..71b4d57e4 100644
> --- a/runtest/hugetlb
> +++ b/runtest/hugetlb
> @@ -22,6 +22,7 @@ hugemmap17 hugemmap17
> hugemmap18 hugemmap18
> hugemmap19 hugemmap19
> hugemmap20 hugemmap20
> +hugemmap21 hugemmap21
> hugemmap05_1 hugemmap05 -m
> hugemmap05_2 hugemmap05 -s
> hugemmap05_3 hugemmap05 -s -m
> diff --git a/testcases/kernel/mem/.gitignore
> b/testcases/kernel/mem/.gitignore
> index dfd372892..74edfa392 100644
> --- a/testcases/kernel/mem/.gitignore
> +++ b/testcases/kernel/mem/.gitignore
> @@ -21,6 +21,7 @@
> /hugetlb/hugemmap/hugemmap18
> /hugetlb/hugemmap/hugemmap19
> /hugetlb/hugemmap/hugemmap20
> +/hugetlb/hugemmap/hugemmap21
> /hugetlb/hugeshmat/hugeshmat01
> /hugetlb/hugeshmat/hugeshmat02
> /hugetlb/hugeshmat/hugeshmat03
> diff --git a/testcases/kernel/mem/hugetlb/hugemmap/hugemmap21.c
> b/testcases/kernel/mem/hugetlb/hugemmap/hugemmap21.c
> new file mode 100644
> index 000000000..481edb4b0
> --- /dev/null
> +++ b/testcases/kernel/mem/hugetlb/hugemmap/hugemmap21.c
> @@ -0,0 +1,131 @@
> +// SPDX-License-Identifier: LGPL-2.1-or-later
> +/*
> + * Copyright (C) 2005-2006 IBM Corporation.
> + * Author: David Gibson & Adam Litke
> + */
> +
> +/*\
> + * [Description]
> + *
> + * Tests copy-on-write semantics of large pages where a number of threads
> + * map the same file with the MAP_PRIVATE flag. The threads then write
> + * into their copy of the mapping and recheck the contents to ensure they
> + * were not corrupted by the other threads.
> + */
> +
> +#include <stdio.h>
> +#include <sys/mount.h>
> +#include <limits.h>
> +#include <sys/param.h>
> +#include <sys/types.h>
> +#include <stdlib.h>
> +#include <string.h>
> +#include <unistd.h>
> +#include <sys/stat.h>
> +#include <fcntl.h>
> +#include <unistd.h>
> +#include <sys/shm.h>
> +#include <sys/wait.h>
> +
> +#include "hugetlb.h"
> +
> +#define BUF_SZ 256
> +#define THREADS 5
> +#define NR_HUGEPAGES 6
> +#define MNTPOINT "hugetlbfs/"
> +
> +static int fd = -1;
> +static long hpage_size;
> +
> +static void do_work(int thread, size_t size, int fd)
> +{
> + char *addr;
> + size_t i;
> + char pattern = thread+65;
> +
> + addr = SAFE_MMAP(NULL, size, PROT_READ|PROT_WRITE, MAP_PRIVATE,
> fd, 0);
> +
> + tst_res(TINFO, "Thread %d (pid %d): Mapped at address %p",
> + thread, getpid(), addr);
> +
> + for (i = 0; i < size; i++)
> + memcpy((char *)addr+i, &pattern, 1);
> +
> + if (msync(addr, size, MS_SYNC))
> + tst_brk(TBROK|TERRNO, "Thread %d (pid %d): msync() failed",
> + thread, getpid());
> +
> + for (i = 0; i < size; i++)
> + if (addr[i] != pattern) {
> + tst_res(TFAIL, "thread %d (pid: %d): Corruption at
> %p; "
> + "Got %c, Expected %c", thread, getpid(),
> + &addr[i], addr[i], pattern);
> + goto cleanup;
> + }
> + tst_res(TINFO, "Thread %d (pid %d): Pattern verified",
> + thread, getpid());
>
Maybe combining the address output with the content of patterns is better?
i.e.
--- a/testcases/kernel/mem/hugetlb/hugemmap/hugemmap21.c
+++ b/testcases/kernel/mem/hugetlb/hugemmap/hugemmap21.c
@@ -45,9 +45,6 @@ static void do_work(int thread, size_t size, int fd)
addr = SAFE_MMAP(NULL, size, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd,
0);
- tst_res(TINFO, "Thread %d (pid %d): Mapped at address %p",
- thread, getpid(), addr);
-
for (i = 0; i < size; i++)
memcpy((char *)addr+i, &pattern, 1);
@@ -62,8 +59,8 @@ static void do_work(int thread, size_t size, int fd)
&addr[i], addr[i], pattern);
goto cleanup;
}
- tst_res(TINFO, "Thread %d (pid %d): Pattern verified",
- thread, getpid());
+ tst_res(TINFO, "Thread %d (pid %d): Pattern %c verified at address
%p",
+ thread, getpid(), pattern, addr);
cleanup:
SAFE_MUNMAP(addr, size);
> +
> +cleanup:
> + SAFE_MUNMAP(addr, size);
> + exit(0);
> +}
> +
> +static void run_test(void)
> +{
> + char *addr;
> + size_t size, itr;
> + int i, pid;
> + pid_t *wait_list;
> +
> + wait_list = SAFE_MALLOC(THREADS * sizeof(pid_t));
> + size = (NR_HUGEPAGES / (THREADS+1)) * hpage_size;
> +
> +
> + /* First, mmap the file with MAP_SHARED and fill with data
> + * If this is not done, then the fault handler will not be
> + * called in the kernel since private mappings will be
> + * created for the children at prefault time.
> + */
> + addr = SAFE_MMAP(NULL, size, PROT_READ|PROT_WRITE, MAP_SHARED, fd,
> 0);
> +
> + for (itr = 0; itr < size; itr += 8)
> + memcpy(addr+itr, "deadbeef", 8);
> +
> + for (i = 0; i < THREADS; i++) {
> + pid = SAFE_FORK();
> +
> + if (pid == 0)
> + do_work(i, size, fd);
> +
> + wait_list[i] = pid;
> + }
> + tst_reap_children();
> +
> + SAFE_MUNMAP(addr, size);
> + free(wait_list);
> + tst_res(TPASS, "mmap COW working as expected.");
> +}
> +
> +static void setup(void)
> +{
> + hpage_size = SAFE_READ_MEMINFO(MEMINFO_HPAGE_SIZE)*1024;
>
We do have a dedicated function named tst_get_hugepage_size();
could be used for getting huge page size.
The rest part looks good to me.
Reviewed-by: Li Wang <liwang@redhat.com>
> + fd = tst_creat_unlinked(MNTPOINT, 0);
> +}
> +
> +static void cleanup(void)
> +{
> + if (fd >= 1)
> + SAFE_CLOSE(fd);
> +}
> +
> +static struct tst_test test = {
> + .needs_root = 1,
> + .mntpoint = MNTPOINT,
> + .needs_hugetlbfs = 1,
> + .needs_tmpdir = 1,
> + .forks_child = 1,
> + .setup = setup,
> + .cleanup = cleanup,
> + .test_all = run_test,
> + .hugepages = {NR_HUGEPAGES, TST_NEEDS},
> +};
> --
> 2.31.1
>
>
--
Regards,
Li Wang
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