xfstests, xfs test 080 fails on arm 32bit

[Dave Chinner]

On Tue, Sep 29, 2015 at 03:32:55PM +0200, Angelo Dureghello wrote:
> Hi,
> 
> executing this test on a 32bit arm. i get (i traced mmapping sizes):
> 
> # ./start_xfs_test.sh
> QA output created by 080
> [  161.827446] XFS (mmcblk0p5): Mounting V4 Filesystem
> [  162.357952] XFS (mmcblk0p5): Ending clean mount
> 
> mmapping 512000000
> mmapping 512000000
> mmapping 512000000
> mmapping 512000000
> mmapping 512000000
> mmapping 512000000
> 
> oio ( 3241) 15:18:17
> ---------------------
> mmap() failed - 0xffffffff 12
> 
> doio ( 3241) 15:18:17
> ---------------------
> mmap-read() request failed:  Cannot allocate memory (12)
> Request number 15
>           fd 4 is file /media/p5/rwtest.file - open flags are 0 O_RDONLY,
>           read done at file offset 978498
>           number of requests is 1, strides per request is 1
>           i/o byte count = 119505
>           memory alignment is unaligned
> 
> syscall:  mmap-read(NULL, 512000000, PROT_READ, MAP_SHARED, 4, 0)
>     file is mmaped to: 0x0
>     file-mem=0xeee42, length=119505, buffer=0x484a6

Does it close/unmap the other files it mmaps? i.e. 32 bit only has a
3GB address space for user applications (IIRC), so the 6th 512MB
mapping will run the process out of address space and hence fail....

> doio ( 3241) 15:18:17
> ---------------------
> doio(): operation 120 returned != 0
> rwtest.sh : iogen reported errors (r=141)
> 
> 
> Is it possible the test was thought to pass on 64bit systems ?

Works just fine on 64 bit systems:

 $ sudo ./check xfs/080
 FSTYP         -- xfs (debug)
 PLATFORM      -- Linux/x86_64 test2 4.3.0-rc1-dgc+
 MKFS_OPTIONS  -- -f -bsize=4096 /dev/sdg
 MOUNT_OPTIONS -- -o context=system_u:object_r:nfs_t:s0 /dev/sdg
 /mnt/scratch

 xfs/080 2s ... 7s
 Ran: xfs/080
 Passed all 1 tests

And looking at the memory footprint:

  PID USER      PR  NI    VIRT    RES    SHR S  %CPU %MEM     TIME+ COMMAND
 3300 root      20   0 3010672   1612   1344 D   4.7  0.0   0:00.14 doio

Yup, 3GB of virtual address space used, 1.6MB of actual memory used.

_require_64bit_userspace is probably needed here...

Cheers,

Dave.
-- 
Dave Chinner
david at fromorbit.com