[LTP] [RFC PATCH] fallocate05: increase the fallocate and defallocate size

[Ralph Siemsen]

On Fri, Sep 24, 2021 at 12:18:45PM +0800, Li Wang wrote:
>
>That's weird.
>
>What about the testing result with unlimit the tmpfs size?

With the .dev_min_size field set to zero, it still causes OOM. Looking 
at the test output, it seems to use 256MB in this case:

tst_test.c:1421: TINFO: Testing on tmpfs
tst_test.c:922: TINFO: Skipping mkfs for TMPFS filesystem
tst_test.c:903: TINFO: Limiting tmpfs size to 256MB
tst_test.c:1353: TINFO: Timeout per run is 0h 15m 00s
tst_fill_fs.c:32: TINFO: Creating file mntpoint/file0 size 21710183
tst_fill_fs.c:32: TINFO: Creating file mntpoint/file1 size 8070086
tst_fill_fs.c:32: TINFO: Creating file mntpoint/file2 size 3971177
tst_fill_fs.c:32: TINFO: Creating file mntpoint/file3 size 36915315
tst_fill_fs.c:32: TINFO: Creating file mntpoint/file4 size 70310993
tst_fill_fs.c:32: TINFO: Creating file mntpoint/file5 size 4807935
tst_fill_fs.c:32: TINFO: Creating file mntpoint/file6 size 90739786
tcf-agent invoked oom-killer: gfp_mask=0x100cca(GFP_HIGHUSER_MOVABLE), order=0, oom_score_adj=0
[...]
Mem-Info:
active_anon:229 inactive_anon:44809 isolated_anon:0
  active_file:7 inactive_file:4 isolated_file:0
  unevictable:0 dirty:0 writeback:0
  slab_reclaimable:1205 slab_unreclaimable:3757
  mapped:334 shmem:42064 pagetables:226 bounce:0
  free:1004 free_pcp:0 free_cma:0
Node 0 active_anon:916kB inactive_anon:179236kB active_file:28kB inactive_file:88kB unevictable:0kB isolated(anon):0kB isolated(file) :0kB mapped:1336kB dirty:0kB writeback:0kB shmem:168256kB writeback_tmp:0kB kernel_stack:1016kB all_unreclaimable? no
Normal free:3776kB min:1872kB low:2340kB high:2808kB 
reserved_highatomic:0KB active_anon:916kB inactive_anon:179236kB active_file:28k B inactive_file:16kB unevictable:0kB writepending:0kB present:262144kB managed:220688kB mlocked:0kB pagetables:904kB bounce:0kB free_pcp:224kB local_pcp:0kB free_cma:0kB
lowmem_reserve[]: 0 0 0
Normal: 1*4kB (M) 1*8kB (M) 22*16kB (U) 35*32kB (UE) 16*64kB (UE) 9*128kB (UE) 0*256kB 0*512kB 0*1024kB 0*2048kB 0*4096kB 0*8192kB 0* 16384kB = 3660kB
42138 total pagecache pages

>> tst_test.c:903: TINFO: Limiting tmpfs size to 64MB
>
>Hmm, set to 16MB, 32MB? test result?

It does not reach the tmpfs test, because btrfs is unhappy:

tst_test.c:922: TINFO: Formatting /dev/loop0 with btrfs opts='' extra opts=''
ERROR: '/dev/loop0' is too small to make a usable filesystem
ERROR: minimum size for each btrfs device is 47185920
tst_test.c:922: TBROK: mkfs.btrfs failed with exit code 1

With a size of 48MB, machine still crashes with OOM.

>Can you post the /proc/meminfo here? I'm curious how
>small memory it is can not tolerate 64M consuming.

Here is what I get right after booting up, before starting ltp.sh tests. 
I've already disabled numerous services (nginx, redis, etc) to try and 
free up more memory.

MemTotal:         220688 kB
MemFree:          121064 kB
MemAvailable:     157484 kB
Buffers:            9376 kB
Cached:            38052 kB
SwapCached:            0 kB
Active:            16320 kB
Inactive:          45176 kB
Active(anon):        844 kB
Inactive(anon):    22492 kB
Active(file):      15476 kB
Inactive(file):    22684 kB
Unevictable:           0 kB
Mlocked:               0 kB
HighTotal:             0 kB
HighFree:              0 kB
LowTotal:         220688 kB
LowFree:          121064 kB
SwapTotal:             0 kB
SwapFree:              0 kB
Dirty:                60 kB
Writeback:             0 kB
AnonPages:         14140 kB
Mapped:            19244 kB
Shmem:              9268 kB
KReclaimable:       6260 kB
Slab:              20816 kB
SReclaimable:       6260 kB
SUnreclaim:        14556 kB
KernelStack:        1008 kB
PageTables:         1160 kB
NFS_Unstable:          0 kB
Bounce:                0 kB
WritebackTmp:          0 kB
CommitLimit:      110344 kB
Committed_AS:      93916 kB
VmallocTotal:    1818624 kB
VmallocUsed:        2308 kB
VmallocChunk:          0 kB
Percpu:              496 kB

Regards,
Ralph