[LTP] [PATCH v2 4/5] syscalls/mallinfo02: Add a basic test to check use mmap or sbrk

[Yang Xu]

Hi Li
>
>
> On Thu, Feb 4, 2021 at 8:12 PM Yang Xu <xuyang2018.jy@cn.fujitsu.com
> <mailto:xuyang2018.jy@cn.fujitsu.com>> wrote:
>
>     According mallinfo man-page, hblkhd member represents
>     "The number of bytes in blocks currently allocated using mmap(2).".
>     For allocations greater than or equal to 128K and that can't be
>     satisfied from
>     the free list, the memory-allocation functions employ mmap(2)
>     instead of increasing
>     the program break using sbrk(2).
>
>     In this case, we test 20k size to use sbrk and 128k size to use mmap.
>
>     Signed-off-by: Yang Xu <xuyang2018.jy@cn.fujitsu.com
>     <mailto:xuyang2018.jy@cn.fujitsu.com>>
>     ---
>     v1->v2:
>     1.Use mallopt(M_MMAP_THRESHOLD, 131072) to avoid dynamic mmap threshold
>     2.Use tst_print_malinfo api
>     runtest/syscalls | 1 +
>     testcases/kernel/syscalls/mallinfo/.gitignore | 1 +
>     .../kernel/syscalls/mallinfo/mallinfo02.c | 64 +++++++++++++++++++
>     3 files changed, 66 insertions(+)
>     create mode 100644 testcases/kernel/syscalls/mallinfo/mallinfo02.c
>
>     diff --git a/runtest/syscalls b/runtest/syscalls
>     index 753340068..a8fa3f7bf 100644
>     --- a/runtest/syscalls
>     +++ b/runtest/syscalls
>     @@ -683,6 +683,7 @@ lstat02 lstat02
>     lstat02_64 lstat02_64
>
>     mallinfo01 mallinfo01
>     +mallinfo02 mallinfo02
>
>     mallopt01 mallopt01
>
>     diff --git a/testcases/kernel/syscalls/mallinfo/.gitignore
>     b/testcases/kernel/syscalls/mallinfo/.gitignore
>     index a7e32a637..678ac277e 100644
>     --- a/testcases/kernel/syscalls/mallinfo/.gitignore
>     +++ b/testcases/kernel/syscalls/mallinfo/.gitignore
>     @@ -1 +1,2 @@
>     /mallinfo01
>     +/mallinfo02
>     diff --git a/testcases/kernel/syscalls/mallinfo/mallinfo02.c
>     b/testcases/kernel/syscalls/mallinfo/mallinfo02.c
>     new file mode 100644
>     index 000000000..d5bed45a8
>     --- /dev/null
>     +++ b/testcases/kernel/syscalls/mallinfo/mallinfo02.c
>     @@ -0,0 +1,64 @@
>     +// SPDX-License-Identifier: GPL-2.0-or-later
>     +/*
>     + * Copyright (c) 2021 FUJITSU LIMITED. All rights reserved.
>     + * Author: Yang Xu <xuyang2018.jy@cn.fujitsu.com
>     <mailto:xuyang2018.jy@cn.fujitsu.com>>
>     + */
>     +
>     +/*\
>     + * [DESCRIPTION]
>     + *
>     + * Basic mallinfo() test for malloc() using sbrk or mmap.
>     + * It size > MMAP_THRESHOLD, it will use mmap. Otherwise, use sbrk.
>     +\*/
>     +
>     +#include "tst_test.h"
>     +#include "tst_safe_macros.h"
>     +#include "tst_mallinfo.h"
>     +
>     +#ifdef HAVE_MALLINFO
>     +void test_mallopt(void)
>
>
> what about renaming to test_mallinfo(void) ?
Yes, sorry for typo.
>
>     +{
>     + struct mallinfo info;
>     + int size;
>     + char *buf;
>     +
>     + buf = SAFE_MALLOC(20480);
>     +
>     + info = mallinfo();
>     + if (info.uordblks > 20480 && info.hblkhd == 0) {
>     + tst_res(TPASS, "malloc() uses sbrk when size < 128k");
>     + } else {
>     + tst_res(TFAIL, "malloc() use mmap when size < 128k");
>     + tst_print_mallinfo("Test malloc(20480)", &info);
>     + }
>     + free(buf);
>     +
>     + info = mallinfo();
>     + size = MAX(info.fordblks, 131072);
>     +
>     + buf = SAFE_MALLOC(size);
>     + info = mallinfo();
>     + if (info.hblkhd > size && info.hblks > 0) {
>     + tst_res(TPASS, "malloc() uses mmap when size >= 128k");
>     + } else {
>     + tst_res(TFAIL, "malloc uses sbrk when size >= 128k");
>
>
> Why not 'TFAIL | TERRNO' ?
I don't see mallinfo() will fail and it should always succeed.
>
>     + tst_print_mallinfo("Test malloc(1024*128)", &info);
>     + }
>     +
>     + free(buf);
>     +}
>     +
>     +static void setup(void)
>     +{
>     + if (mallopt(M_MMAP_THRESHOLD, 131072) == 0)
>     + tst_res(TFAIL, "mallopt(M_MMAP_THRESHOLD, 128K) failed");
>
>
> Here as well.
Look mallopt man-pages, it said "
RETURN VALUE
        On success, mallopt() returns 1.  On error, it returns 0.
ERRORS
        On error, errno is not set
"
That is why I don't use TERRNO.

>
>     +}
>     +
>     +static struct tst_test test = {
>     + .setup = setup,
>     + .test_all = test_mallopt,
>     +};
>     +
>     +#else
>     +TST_TEST_TCONF("system doesn't implement non-POSIX mallinfo()");
>     +#endif
>     --
>     2.23.0
>
>
>
>
>
> --
> Regards,
> Li Wang