[LTP] [PATCH v4] Migrating the libhugetlbfs/testcases/shm-gettest.c test

[Cyril Hrubis]

Hi!
> Test Description: This testcase creates shared memory segments
> backed by hugepages, writes specific patterns to each segment,
> verifies pattern and detaches a shared memory segments in a loop.
> 
> This looping test was added to verify the functionality of
> large page backed shared memory segments. A segment is created,
> written, verified, and detached for specified number of times.
> 
> -Updated 'kernel/mem/.gitignore'
> -Updated 'runtest/hugetlb' for number of iterations with -i 10
> 
> Signed-off-by: Sachin P Bappalige <sachinpb@linux.ibm.com>
> ---
>  runtest/hugetlb                               |  1 +
>  testcases/kernel/mem/.gitignore               |  1 +
>  .../mem/hugetlb/hugeshmget/hugeshmget06.c     | 78 +++++++++++++++++++
>  3 files changed, 80 insertions(+)
>  create mode 100644 testcases/kernel/mem/hugetlb/hugeshmget/hugeshmget06.c
> 
> diff --git a/runtest/hugetlb b/runtest/hugetlb
> index 299c07ac9..f294e9aaa 100644
> --- a/runtest/hugetlb
> +++ b/runtest/hugetlb
> @@ -55,3 +55,4 @@ hugeshmget01 hugeshmget01 -i 10
>  hugeshmget02 hugeshmget02 -i 10
>  hugeshmget03 hugeshmget03 -i 10
>  hugeshmget05 hugeshmget05 -i 10
> +hugeshmget06 hugeshmget06 -i 10
> diff --git a/testcases/kernel/mem/.gitignore b/testcases/kernel/mem/.gitignore
> index c96fe8bfc..d88484fa1 100644
> --- a/testcases/kernel/mem/.gitignore
> +++ b/testcases/kernel/mem/.gitignore
> @@ -47,6 +47,7 @@
>  /hugetlb/hugeshmget/hugeshmget02
>  /hugetlb/hugeshmget/hugeshmget03
>  /hugetlb/hugeshmget/hugeshmget05
> +/hugetlb/hugeshmget/hugeshmget06
>  /ksm/ksm01
>  /ksm/ksm02
>  /ksm/ksm03
> diff --git a/testcases/kernel/mem/hugetlb/hugeshmget/hugeshmget06.c b/testcases/kernel/mem/hugetlb/hugeshmget/hugeshmget06.c
> new file mode 100644
> index 000000000..85a731113
> --- /dev/null
> +++ b/testcases/kernel/mem/hugetlb/hugeshmget/hugeshmget06.c
> @@ -0,0 +1,78 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/*
> + * Copyright (C) 2005-2006, IBM Corporation.
> + * Author: David Gibson & Adam Litke
> + */
> +
> +/*\
> + * [Description]
> + * This testcase creates shared memory segments backed by hugepages,
> + * writes specific patterns to each segment, verifies pattern,
> + * and detaches a shared memory segments in a loop.
> + * It ensures that the hugepage backed shared memory functionalities
> + * works correctly by validating the data written to segment.
> + */
> +
> +#include "hugetlb.h"
> +#include "tst_safe_sysv_ipc.h"
> +
> +#define MNTPOINT "hugetlbfs/"
> +#define NR_HUGEPAGES 4
> +
> +static long hpage_size;
> +static int shmid = -1, key = -1;
> +
> +static void run_test(void)
> +{
> +	size_t i, j;
> +	char pattern;
> +	char *shmaddr;
> +
> +	shmaddr = SAFE_SHMAT(shmid, 0, SHM_RND);
> +	tst_res(TINFO, "shmaddr: %p", shmaddr);
> +
> +	for (i = 0; i < NR_HUGEPAGES; i++) {
> +		pattern = 65 + (i % 26);
> +		tst_res(TINFO, "Touching %p with %c",
> +		shmaddr + (i * hpage_size), pattern);
> +		memset(shmaddr + (i * hpage_size), pattern, hpage_size);
> +	}
> +
> +	for (i = 0; i < NR_HUGEPAGES; i++) {
> +		pattern = 65 + (i % 26);
> +		tst_res(TINFO, "Verifying %p", (shmaddr + (i * hpage_size)));
> +		for (j = 0; j < (size_t)hpage_size; j++)
> +			if (*(shmaddr + (i * hpage_size) + j) != pattern) {
> +				tst_res(TFAIL, "Got wrong byte 0x%02x expected 0x%02x",
> +						*(shmaddr + (i * hpage_size) + j),
> +						pattern);
> +				return;
> +			}
> +	}
> +	SAFE_SHMDT((const void *)shmaddr);
> +	tst_res(TPASS, "shm hugepages works correctly");
> +}
> +
> +static void setup(void)
> +{
> +	hpage_size = tst_get_hugepage_size();
> +	tst_res(TINFO, "hugepage size is %ld", hpage_size);
> +	shmid = SAFE_SHMGET(key, NR_HUGEPAGES * hpage_size, SHM_HUGETLB|IPC_CREAT|SHM_R|SHM_W);

This uses hardcoded key (-1). Why can't we use IPC_PRIVATE here instead?

> +	tst_res(TINFO, "shmid: 0x%x", shmid);
> +}
> +
> +static void cleanup(void)
> +{
> +	if (shmid >= 0)
> +		SAFE_SHMCTL(shmid, IPC_RMID, NULL);
> +}
> +
> +static struct tst_test test = {
> +	.needs_root = 1,
> +	.mntpoint = MNTPOINT,
> +	.needs_hugetlbfs = 0,

If you do not need it, just do not list it here. Uninitialized variables
are set to zero automatically.

> +	.setup = setup,
> +	.cleanup = cleanup,
> +	.test_all = run_test,
> +	.hugepages = {NR_HUGEPAGES, TST_NEEDS},
> +};
> -- 
> 2.43.0
> 

-- 
Cyril Hrubis
chrubis@suse.cz