I have a somewhat complex (but practical) situation I'm trying to
measure (looking at Goyal's io-controller patches).
o 24-disk MD RAID10 set (/dev/md0)
o 12 linear LV volumes crafted from /dev/md0
o Ext3 FS created on each LV volume
o 16GiB test file created on each FS
# du -s -h /mnt/lv[01]/data.bin
33G /mnt/lv0/data.bin
33G /mnt/lv1/data.bin
When I execute the following job file (only using 2 of the 12 files/FS):
[global]
rw=rw
rwmixread=80
randrepeat=1
size=32g
direct=0
ioengine=libaio
iodepth=32
iodepth_low=32
iodepth_batch=32
iodepth_batch_complete=6
overwrite=0
bs=4k
runtime=30
[lv0]
filename=/mnt/lv0/data.bin
[test]
filename=/mnt/lv1/data.bin
the I/O portion of the run completes, but whilst attempting to display
the Disk stats it hangs whilst outputting:
...
Run status group 0 (all jobs):
READ: io=3,602MB, aggrb=120MB/s, minb=61,754KB/s, maxb=64,135KB/s,
mint=30002msec, maxt=30005msec
WRITE: io=903MB, aggrb=30,813KB/s, minb=15,537KB/s, maxb=16,016KB/s,
mint=30002msec, maxt=30005msec
Disk stats (read/write):
<<<hangs...>>>
Breaking in (via gdb) yields:
(gdb) where
#0 0x0000000000428bb4 in aggregate_slaves_stats
(masterdu=0x7f21bbf511e8)
at diskutil.c:458
#1 0x000000000042905c in show_disk_util () at diskutil.c:528
#2 0x00000000004121bb in show_run_stats () at stat.c:663
#3 0x000000000040acad in main (argc=2, argv=0x7fff6b83bba8) at
fio.c:1654
setting a break at:
454 ios[0] += dus->ios[0];
and using 'cont' & "print *slavedu" yields:
(gdb) print *slavedu
$3 = {list = {next = 0x28000156a7, prev = 0x1571500006e19}, slavelist =
{
next = 0x7f21bbf513f8, prev = 0x7f21bbf513f8},
name = 0x74b4 <Address 0x74b4 out of bounds>,
sysfs_root = 0x4aaa6cce <Address 0x4aaa6cce out of bounds>,
path = "\030�\r\000\000\000\000\000\000\020i�!\177\000\000\000\000\000
\000\000\000\000\000�Z�Z\000\000\000\000\024\000\000\000ﾭ�dm-1\000\000
\000\000�Z�Z", '\0' <repeats 12 times>, "�\001\000\000ﾭ��G�!\177\000
\000�G�!\177\000\000�G�!\177\000\000�G�!\177\000\000�I�!\177\000\000�W
\203k�\177\000\000/sys/block/dm-1/slaves/../../md0/stat", '\0' <repeats
98 times>, major = 0, minor = 0,
dus = {ios = {0, 0}, merges = {0, 0}, sectors = {0, 0}, ticks = {0,
0},
io_ticks = 0, time_in_queue = 0}, last_dus = {ios = {0, 0}, merges =
{0,
0}, sectors = {0, 0}, ticks = {0, 0}, io_ticks = 0, time_in_queue
= 0},
slaves = {next = 0x0, prev = 0x0}, msec = 9, time = {tv_sec = 0,
tv_usec = 0}, lock = 0x0, users = 0}
(gdb) cont
Continuing.
Breakpoint 1, aggregate_slaves_stats (masterdu=0x7f21bbf511e8)
at diskutil.c:454
454 ios[0] += dus->ios[0];
(gdb) print *slavedu
$4 = {list = {next = 0x7f21bbf515e8, prev = 0x7f21bbf511e8}, slavelist =
{
next = 0x7f21bbf54780, prev = 0x7f21bbf54780},
name = 0x7f21bbf515c8 "md0",
sysfs_root = 0x7fff6b8357f0 "/sys/block/dm-1/slaves/../../md0",
path = "/sys/block/dm-0/slaves/../../md0/stat", '\0' <repeats 218
times>,
major = 9, minor = 0, dus = {ios = {0, 0}, merges = {0, 0}, sectors =
{0,
0}, ticks = {0, 0}, io_ticks = 0, time_in_queue = 0}, last_dus =
{ios = {
567924, 118793}, merges = {0, 0}, sectors = {71929094, 950344},
ticks = {
0, 0}, io_ticks = 0, time_in_queue = 0}, slaves = {
next = 0x7f21bbf515f8, prev = 0x7f21bbf543f8}, msec = 0, time = {
tv_sec = 1252682928, tv_usec = 935566}, lock = 0x7f21bc973000, users
= 0}
(gdb) cont
Continuing.
Breakpoint 1, aggregate_slaves_stats (masterdu=0x7f21bbf511e8)
at diskutil.c:454
454 ios[0] += dus->ios[0];
(gdb) print *slavedu
$5 = {list = {next = 0x28000156a7, prev = 0x1571500006e19}, slavelist =
{
next = 0x7f21bbf513f8, prev = 0x7f21bbf513f8},
name = 0x74b4 <Address 0x74b4 out of bounds>,
sysfs_root = 0x4aaa6cce <Address 0x4aaa6cce out of bounds>,
path = "\030�\r\000\000\000\000\000\000\020i�!\177\000\000\000\000\000
\000\000\000\000\000�Z�Z\000\000\000\000\024\000\000\000ﾭ�dm-1\000\000
\000\000�Z�Z", '\0' <repeats 12 times>, "�\001\000\000ﾭ��G�!\177\000
\000�G�!\177\000\000�G�!\177\000\000�G�!\177\000\000�I�!\177\000\000�W
\203k�\177\000\000/sys/block/dm-1/slaves/../../md0/stat", '\0' <repeats
98 times>, major = 0, minor = 0,
dus = {ios = {0, 0}, merges = {0, 0}, sectors = {0, 0}, ticks = {0,
0},
io_ticks = 0, time_in_queue = 0}, last_dus = {ios = {0, 0}, merges =
{0,
0}, sectors = {0, 0}, ticks = {0, 0}, io_ticks = 0, time_in_queue
= 0},
slaves = {next = 0x0, prev = 0x0}, msec = 9, time = {tv_sec = 0,
tv_usec = 0}, lock = 0x0, users = 0}
and then it seems to be bouncing between these two "things".
Now using a totally separate disk & FS & data file:
# du -s -h /mnt/lv0/data.bin /mnt/test/data.bin
33G /mnt/lv0/data.bin
33G /mnt/test/data.bin
(/mnt/test is *not* constructed from the MD device)
and changing the job file to look like:
[test]
filename=/mnt/test/data.bin
(Removing the /dev/vg/lv1 file)
It runs to completion correctly.
It seems to me that there may be some error in the logic dealing with
finding the underlying devices for different mount points/files the come
to the same underlying device (/dev/md0, in this case?)?
Alan
--
To unsubscribe from this list: send the line "unsubscribe fio" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
