[LTP] [PATCH 1/1] swapping01: make test more robust

[Petr Vorel <pvorel@suse.cz>]

Hi Alexander, Li,

First I found quite hard to have correct setup to avoid TCONF "Not enough swap
space to test". It often requires to add additional swap file via mkswap && swapon
and use some RAM with:

dd if=/dev/zero of=/dev/shm/fill bs=1k count=14024k

It'd be great if test could do required setup itself.
And it'd also help at least to print swap_free_init and mem_over_max in that TCONF:

        if (swap_free_init < mem_over_max)
-               tst_brk(TCONF, "Not enough swap space to test.");
+               tst_brk(TCONF, "Not enough swap space to test (%ld < %ld)", swap_free_init, mem_over_max);


I tried to debug swapping01 on s390x (without this patch) with using additional
swap and eat RAM with dd. and got bus error (core dumped). Is that due too
aggressive memory eating? I'm not able to crash it on intel arch.

# strace ./swapping01
execve("./swapping01", ["./swapping01"], 0x3ffdd9fdd30 /* 163 vars */) = 0
brk(NULL)                               = 0x18ce000
mmap(NULL, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x3ffb41fc000
access("/etc/ld.so.preload", R_OK)      = -1 ENOENT (No such file or directory)
openat(AT_FDCWD, "/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = 3
fstat(3, {st_mode=S_IFREG|0644, st_size=51982, ...}) = 0
mmap(NULL, 51982, PROT_READ, MAP_PRIVATE, 3, 0) = 0x3ffb4100000
close(3)                                = 0
openat(AT_FDCWD, "/lib64/libpthread.so.0", O_RDONLY|O_CLOEXEC) = 3
read(3, "\177ELF\2\2\1\0\0\0\0\0\0\0\0\0\0\3\0\26\0\0\0\1\0\0\0\0\0\0\205\370"..., 832) = 832
fstat(3, {st_mode=S_IFREG|0755, st_size=160168, ...}) = 0
mmap(NULL, 143720, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x3ffb4080000
mprotect(0x3ffb409d000, 4096, PROT_NONE) = 0
mmap(0x3ffb409e000, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x1d000) = 0x3ffb409e000
mmap(0x3ffb40a0000, 12648, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x3ffb40a0000
close(3)                                = 0
openat(AT_FDCWD, "/lib64/libc.so.6", O_RDONLY|O_CLOEXEC) = 3
read(3, "\177ELF\2\2\1\3\0\0\0\0\0\0\0\0\0\3\0\26\0\0\0\1\0\0\0\0\0\2\263\250"..., 832) = 832
fstat(3, {st_mode=S_IFREG|0755, st_size=2012560, ...}) = 0
mmap(NULL, 1765032, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x3ffb3e80000
mprotect(0x3ffb4025000, 4096, PROT_NONE) = 0
mmap(0x3ffb4026000, 24576, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x1a5000) = 0x3ffb4026000
mmap(0x3ffb402c000, 11944, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x3ffb402c000
close(3)                                = 0
mmap(NULL, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x3ffb41fa000
mprotect(0x3ffb4026000, 12288, PROT_READ) = 0
mprotect(0x3ffb409e000, 4096, PROT_READ) = 0
mprotect(0x1025000, 4096, PROT_READ)    = 0
mprotect(0x3ffb41a7000, 4096, PROT_READ) = 0
munmap(0x3ffb4100000, 51982)            = 0
set_tid_address(0x3ffb41fb060)          = 124658
set_robust_list(0x3ffb41fb070, 24)      = 0
rt_sigaction(SIGRTMIN, {sa_handler=0x3ffb4088050, sa_mask=[], sa_flags=SA_SIGINFO}, NULL, 8) = 0
rt_sigaction(SIGRT_1, {sa_handler=0x3ffb4088108, sa_mask=[], sa_flags=SA_RESTART|SA_SIGINFO}, NULL, 8) = 0
rt_sigprocmask(SIG_UNBLOCK, [RTMIN RT_1], NULL, 8) = 0
prlimit64(0, RLIMIT_STACK, NULL, {rlim_cur=8192*1024, rlim_max=RLIM64_INFINITY}) = 0
getpid()                                = 124658
geteuid()                               = 0
openat(AT_FDCWD, "/sys/devices/system/cpu/online", O_RDONLY|O_CLOEXEC) = 3
read(3, "0-1\n", 8192)                  = 4
close(3)                                = 0
access("/dev/shm", F_OK)                = 0
getpid()                                = 124658
openat(AT_FDCWD, "/dev/shm/ltp_swapping01_124658", O_RDWR|O_CREAT|O_EXCL, 0600) = 3
chmod("/dev/shm/ltp_swapping01_124658", 0666) = 0
ftruncate(3, 4096)                      = 0
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_SHARED, 3, 0) = 0x3ffb4100000
unlink("/dev/shm/ltp_swapping01_124658") = 0
close(3)                                = 0
rt_sigaction(SIGALRM, {sa_handler=0x1005a88, sa_mask=[ALRM], sa_flags=SA_RESTART}, {sa_handler=SIG_DFL, sa_mask=[], sa_flags=0}, 8) = 0
rt_sigaction(SIGUSR1, {sa_handler=0x1005910, sa_mask=[USR1], sa_flags=SA_RESTART}, {sa_handler=SIG_DFL, sa_mask=[], sa_flags=0}, 8) = 0
--- SIGBUS {si_signo=SIGBUS, si_code=BUS_ADRERR, si_addr=0x3ffb4100000} ---
+++ killed by SIGBUS (core dumped) +++
Bus error (core dumped)

$ cat /proc/meminfo
MemTotal:       12300520 kB
MemFree:         3218768 kB
MemAvailable:    5748908 kB
Buffers:            6956 kB
Cached:          8756848 kB
SwapCached:            0 kB
Active:          6651856 kB
Inactive:        2152212 kB
Active(anon):    6198384 kB
Inactive(anon):    24904 kB
Active(file):     453472 kB
Inactive(file):  2127308 kB
Unevictable:       18292 kB
Mlocked:           18292 kB
SwapTotal:       2538488 kB
SwapFree:        2538488 kB
Dirty:                16 kB
Writeback:             0 kB
AnonPages:         56544 kB
Mapped:            32840 kB
Shmem:           6175368 kB
KReclaimable:     105912 kB
Slab:             156604 kB
SReclaimable:     105912 kB
SUnreclaim:        50692 kB
KernelStack:        6672 kB
PageTables:         1976 kB
NFS_Unstable:          0 kB
Bounce:                0 kB
WritebackTmp:          0 kB
CommitLimit:     8688748 kB
Committed_AS:    6360300 kB
VmallocTotal:   132120576 kB
VmallocUsed:       49520 kB
VmallocChunk:          0 kB
Percpu:            67680 kB
AnonHugePages:     22528 kB
ShmemHugePages:        0 kB
ShmemPmdMapped:        0 kB
CmaTotal:              0 kB
CmaFree:               0 kB
HugePages_Total:       0
HugePages_Free:        0
HugePages_Rsvd:        0
HugePages_Surp:        0
Hugepagesize:       1024 kB
Hugetlb:               0 kB
DirectMap4k:        6144 kB
DirectMap1M:     4188160 kB
DirectMap2G:     8388608 kB

Kind regards,
Petr